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RIFAXIMIN

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Classification   |    Detailed evidence-based information

Substances Included Synonyms

Therapeutic Toxic Class

    A) Rifaximin, a derivative of rifamycin, is a semisynthetic, nonsystemic antibiotic. It acts by binding to the beta-subunit of bacterial DNA-dependent RNA polymerase which results in the inhibition of bacterial RNA synthesis.

Specific Substances

    1) Fatroximin
    2) L-105
    3) L-105 (Ansamacrolide antibiotic)
    4) L 105SV
    5) Normix
    6) Rifacol
    7) Rifamycin L 105
    8) Rifamycin L 105SV
    9) Rifaxidin
    10) Rifaximina
    11) Rifaximine
    12) Ritacol
    13) 4-Deoxy-4'-methylpyrido(1',2'-1,2)imidazo(5,4-c)rifamycin SV
    14) Molecular Formula: C43-H51-N3-O11
    15) CAS 80621-81-4

Available Forms Sources

    A) FORMS
    1) Rifaximin is available in the US as a 200 mg and 550 mg tablets for oral administration (Prod Info XIFAXAN(R) oral tablets, 2010).
    B) USES
    1) Rifaximin is used to treat patients 12 years of age or older with traveler's diarrhea caused by noninvasive strains of Escherichia coli. It is also used to reduce the risk of overt hepatic encephalopathy recurrence in patients 18 years of age or older (Prod Info XIFAXAN(R) oral tablets, 2010).

Overview

Life Support

    A) This overview assumes that basic life support measures have been instituted.

Clinical Effects

    0.2.1) SUMMARY OF EXPOSURE
    A) WITH THERAPEUTIC USE
    1) The most common adverse effects (greater than or equal to 2%) are flatulence, headache, abdominal pain, rectal tenesmus, defecation urgency, nausea, vomiting, constipation, and fever. However, these effects may be caused by the underlying disease.
    2) Other reported adverse effects include allergic dermatitis, rash, urticaria, pruritus, weight loss, abdominal distension, diarrhea, dry throat, gingival disorder, inguinal hernia, dry lips, blood in stool, hematuria, choluria, dysuria, polyuria, proteinuria, urinary frequency, lymphocytosis, monocytosis, neutropenia, tinnitus, increases in aspartate aminotransferase, arthralgia, muscle spasms, myalgia, neck pain, headache, motion sickness, fatigue, malaise, abnormal dreams, dizziness, migraine, insomnia, syncope, loss of taste, respiratory tract infections, dyspnea, nasal passage irritation, nasopharyngitis, pharyngitis, pharyngolaryngeal pain, rhinitis, and rhinorrhea.
    B) WITH POISONING/EXPOSURE
    1) Overdose data are limited. Following the administration of doses higher than the recommended dose (greater than 600 mg/day), adverse effects were similar to those observed at lower doses (recommended dose of 200 mg taken three times a day).
    0.2.3) VITAL SIGNS
    A) WITH THERAPEUTIC USE
    1) Fever (3%) has been reported with the use of rifaximin in clinical trials (n=320). However, it may be caused by the underlying disease (Prod Info XIFAXAN(R) oral tablets, 2010).
    0.2.20) REPRODUCTIVE
    A) Teratogenicity has been reported in animals.

Laboratory Monitoring

    A) Monitor fluid and electrolyte status in patients with severe vomiting and/or diarrhea.
    B) Monitor CBC, renal and hepatic function tests in symptomatic patients.

Treatment Overview

    0.4.2) ORAL/PARENTERAL EXPOSURE
    A) Rifaximin undergoes minimal absorption from the gastrointestinal tract (bioavailability less than 0.4%). GI decontamination is generally not indicated.
    B) In case of rifaximin overdose, treatment is symptomatic and supportive.

Range Of Toxicity

    A) Overdose data is limited. Following the administration of doses higher than the recommended dose (greater than 600 mg/day), adverse effects were similar to those observed at lower doses (recommended dose of 200 mg taken three times a day).

Clinical Effects

Summary Of Exposure

    A) WITH THERAPEUTIC USE
    1) The most common adverse effects (greater than or equal to 2%) are flatulence, headache, abdominal pain, rectal tenesmus, defecation urgency, nausea, vomiting, constipation, and fever. However, these effects may be caused by the underlying disease.
    2) Other reported adverse effects include allergic dermatitis, rash, urticaria, pruritus, weight loss, abdominal distension, diarrhea, dry throat, gingival disorder, inguinal hernia, dry lips, blood in stool, hematuria, choluria, dysuria, polyuria, proteinuria, urinary frequency, lymphocytosis, monocytosis, neutropenia, tinnitus, increases in aspartate aminotransferase, arthralgia, muscle spasms, myalgia, neck pain, headache, motion sickness, fatigue, malaise, abnormal dreams, dizziness, migraine, insomnia, syncope, loss of taste, respiratory tract infections, dyspnea, nasal passage irritation, nasopharyngitis, pharyngitis, pharyngolaryngeal pain, rhinitis, and rhinorrhea.
    B) WITH POISONING/EXPOSURE
    1) Overdose data are limited. Following the administration of doses higher than the recommended dose (greater than 600 mg/day), adverse effects were similar to those observed at lower doses (recommended dose of 200 mg taken three times a day).

Vital Signs

    3.3.1) SUMMARY
    A) WITH THERAPEUTIC USE
    1) Fever (3%) has been reported with the use of rifaximin in clinical trials (n=320). However, it may be caused by the underlying disease (Prod Info XIFAXAN(R) oral tablets, 2010).

Heent

    3.4.4) EARS
    A) WITH THERAPEUTIC USE
    1) Tinnitus, ear pain and motion sickness have been reported infrequently with the use of rifaximin (Prod Info XIFAXAN(R) oral tablets, 2010).

Respiratory

    3.6.2) CLINICAL EFFECTS
    A) RESPIRATORY FINDING
    1) WITH THERAPEUTIC USE
    a) Respiratory tract infections, dyspnea, nasal passage irritation, nasopharyngitis, pharyngitis, pharyngolaryngeal pain, rhinitis and rhinorrhea have been reported with the use of rifaximin (Prod Info XIFAXAN(R) oral tablets, 2010).

Neurologic

    3.7.2) CLINICAL EFFECTS
    A) CENTRAL NERVOUS SYSTEM FINDING
    1) WITH THERAPEUTIC USE
    a) Headache (10%), motion sickness, fatigue, malaise, abnormal dreams, dizziness, migraine, insomnia, syncope, and loss of taste have been reported with the use of rifaximin (Prod Info XIFAXAN(R) oral tablets, 2010).
    b) Headache was reported in one of eighteen healthy volunteers after oral administration of 400 mg rifaximin (Descombe et al, 1994).

Gastrointestinal

    3.8.2) CLINICAL EFFECTS
    A) GASTROINTESTINAL TRACT FINDING
    1) WITH THERAPEUTIC USE
    a) Flatulence (11%), abdominal pain (7%), rectal tenesmus (7%), defecation urgency (6%), nausea (5%), constipation (4%), vomiting (2%), abdominal distension, diarrhea, dry throat, dry lips, and blood in stool have been reported with the use of rifaximin (600 mg daily) in clinical trials (n=320). However, these effects may be caused by the underlying disease (Prod Info XIFAXAN(R) oral tablets, 2010; Gillis & Brogden, 1995; Bucci & Palmieri, 1993). In clinical studies of patients receiving 1100 mg daily, 20 (14%) patients developed nausea, which was similar to the placebo group (n=21 (13%)) (Prod Info XIFAXAN(R) oral tablets, 2010).
    b) The detection of adverse gastrointestinal events probably would have been difficult in patients with infectious diarrhea or diverticular disease, given the similarity of presenting disease symptoms to common gastrointestinal complaints (Gillis & Brogden, 1995).
    B) DIARRHEA
    1) WITH THERAPEUTIC USE
    a) CLOSTRIDIUM DIFFICILE-ASSOCIATED DIARRHEA
    1) Clostridium difficile-associated diarrhea has been reported with rifaximin during postmarketing experience. Symptoms may range from mild diarrhea to fatal colitis (Prod Info XIFAXAN(R) oral tablets, 2010)

Hepatic

    3.9.2) CLINICAL EFFECTS
    A) INJURY OF LIVER
    1) WITH THERAPEUTIC USE
    a) Increases in aspartate aminotransferase have been reported with the use of rifaximin (Prod Info XIFAXAN(R) oral tablets, 2010).

Genitourinary

    3.10.2) CLINICAL EFFECTS
    A) UROGENITAL FINDING
    1) WITH THERAPEUTIC USE
    a) Hematuria, choluria, dysuria, polyuria, proteinuria and urinary frequency have been reported infrequently with rifaximin use (Prod Info XIFAXAN(R) oral tablets, 2010).

Hematologic

    3.13.2) CLINICAL EFFECTS
    A) HEMATOLOGY FINDING
    1) WITH THERAPEUTIC USE
    a) Lymphocytosis, monocytosis, and neutropenia have been reported infrequently with rifaximin use (Prod Info XIFAXAN(R) oral tablets, 2010).

Dermatologic

    3.14.2) CLINICAL EFFECTS
    A) SKIN FINDING
    1) WITH THERAPEUTIC USE
    a) Prolonged therapy with high doses of rifaximin has been associated with infrequent urticarial skin reaction (Gillis & Brogden, 1995).
    b) Increased sweating has been reported with the use of rifaximin (Prod Info Xifaxan(TM), 2004).

Musculoskeletal

    3.15.2) CLINICAL EFFECTS
    A) PAIN
    1) WITH THERAPEUTIC USE
    a) Arthralgia, muscle spasms, myalgia, and neck pain have been reported infrequently with rifaximin use (Prod Info XIFAXAN(R) oral tablets, 2010).

Endocrine

    3.16.2) CLINICAL EFFECTS
    A) WEIGHT LOSS FINDING
    1) WITH THERAPEUTIC USE
    a) Weight loss was reported in two patients treated with rifaximin for hepatic encephalopathy (Bucci & Palmieri, 1993).

Immunologic

    3.19.2) CLINICAL EFFECTS
    A) HYPERSENSITIVITY REACTION
    1) WITH THERAPEUTIC USE
    a) Allergic dermatitis, rash, urticaria, angioneurotic edema, flushing, pruritus and anaphylaxis have been reported with the use of rifaximin during postmarketing surveillance. In some cases, the events occurred within 15 minutes of drug administration (Prod Info XIFAXAN(R) oral tablets, 2010).

Reproductive

    3.20.1) SUMMARY
    A) Teratogenicity has been reported in animals.
    3.20.2) TERATOGENICITY
    A) ANIMAL STUDIES
    1) During animal studies, rifaximin was teratogenic at doses up to 33 times the recommended human dose. No effect on pre- or postnatal development was reported at doses up to 300 mg/kg per day (up to 5 times the recommended human dose for traveler's diarrhea) (Prod Info XIFAXAN(R) oral tablets, 2015).
    3.20.3) EFFECTS IN PREGNANCY
    A) RISK SUMMARY
    1) Administer during pregnancy only if the benefit justifies the risk to the fetus and inform the patient of the potential for fetal harm (Prod Info XIFAXAN(R) oral tablets, 2015).
    3.20.4) EFFECTS DURING BREAST-FEEDING
    A) RISK SUMMARY
    1) It is unknown if rifaximin is excreted in human milk. Exercise caution when administering to a lactating woman and weigh the benefits of breastfeeding with the potential risk to the infant (Prod Info XIFAXAN(R) oral tablets, 2015).
    3.20.5) FERTILITY
    A) ANIMAL STUDIES
    1) There were no reports of adverse effects on fertility in animals administered rifaximin at doses up to 300 mg/kg per day (approximately 5 times the recommended human dose for traveler's diarrhea) (Prod Info XIFAXAN(R) oral tablets, 2015).

Carcinogenicity

    3.21.1) IARC CATEGORY
    A) IARC Carcinogenicity Ratings for CAS80621-81-4 (International Agency for Research on Cancer (IARC), 2016; International Agency for Research on Cancer, 2015; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010a; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2008; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2007; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2006; IARC, 2004):
    1) Not Listed

Laboratory Monitoring

Monitoring Parameters Levels

    4.1.1) SUMMARY
    A) Monitor fluid and electrolyte status in patients with severe vomiting and/or diarrhea.
    B) Monitor CBC, renal and hepatic function tests in symptomatic patients.

Treatment

Life Support

    A) Support respiratory and cardiovascular function.

Monitoring

    A) Monitor fluid and electrolyte status in patients with severe vomiting and/or diarrhea.
    B) Monitor CBC, renal and hepatic function tests in symptomatic patients.

Oral Exposure

    6.5.1) PREVENTION OF ABSORPTION/PREHOSPITAL
    A) Rifaximin undergoes minimal absorption from the gastrointestinal tract (bioavailability less than 0.4%). GI decontamination is generally not indicated.
    6.5.2) PREVENTION OF ABSORPTION
    A) SUMMARY
    1) Rifaximin undergoes minimal absorption from the gastrointestinal tract (bioavailability less than 0.4%). GI decontamination is generally not indicated.
    6.5.3) TREATMENT
    A) SUPPORT
    1) In case of rifaximin overdose, treatment should be symptomatic and supportive.
    B) MONITORING OF PATIENT
    1) Monitor fluid and electrolyte status in patients with severe vomiting and/or diarrhea.
    2) Monitor CBC, renal function and hepatic enzymes in symptomatic patients.

Enhanced Elimination

    A) HEMODIALYSIS
    1) There is no information regarding the effectiveness of hemodialysis or hemoperfusion for the removal of rifaximin from plasma. Since systemic absorption is minimal (bioavailability less than 0.4%), methods to enhance systemic elimination are unlikely to be necessary.

Range Of Toxicity

Summary

    A) Overdose data is limited. Following the administration of doses higher than the recommended dose (greater than 600 mg/day), adverse effects were similar to those observed at lower doses (recommended dose of 200 mg taken three times a day).

Therapeutic Dose

    7.2.1) ADULT
    A) HEPATIC ENCEPHALOPATHY
    1) 550 mg tablet orally 2 times daily (Prod Info XIFAXAN(R) oral tablets, 2015).
    B) IRRITABLE BOWEL SYNDROME
    1) 550 mg tablet orally 3 times daily for 14 days; this regimen can be repeated up to 2 times if needed (Prod Info XIFAXAN(R) oral tablets, 2015).
    C) TRAVELERS' DIARRHEA
    1) 200 mg tablet orally 3 times daily for 3 days (Prod Info XIFAXAN(R) oral tablets, 2015).
    7.2.2) PEDIATRIC
    A) HEPATIC ENCEPHALOPATHY
    1) The safety and effectiveness of rifaximin in pediatric patients less than 18 years of age have not been established (Prod Info XIFAXAN(R) oral tablets, 2015).
    B) IRRITABLE BOWEL SYNDROME
    1) The safety and effectiveness of rifaximin in pediatric patients less than 18 years of age have not been established (Prod Info XIFAXAN(R) oral tablets, 2015).
    C) TRAVELERS' DIARRHEA
    1) 12 YEARS OR OLDER: 200 mg tablet orally 3 times daily for 3 days (Prod Info XIFAXAN(R) oral tablets, 2015).
    2) LESS THAN 12 YEARS: Safety and effectiveness in pediatric patients less than 12 years of age have not been established (Prod Info XIFAXAN(R) oral tablets, 2015).

Maximum Tolerated Exposure

    A) Overdose data is limited. Following the administration of doses higher than the recommended dose (greater than 600 mg/day), adverse effects were similar to those observed at lower doses (recommended dose of 200 mg taken three times a day) (Prod Info Xifaxan(TM), 2004).

Serum Plasma Blood Concentrations

    7.5.1) THERAPEUTIC CONCENTRATIONS
    A) THERAPEUTIC CONCENTRATION LEVELS
    1) Gram-positive bacteria, MIC from 0.015 to 2 mcg/mL. Value indicates in vitro minimum inhibitory concentration; antibacterial activity of rifaximin is greater against gram-positive than against gram-negative bacteria (Venturini & Marchi, 1986).

Workplace Standards

    A) ACGIH TLV Values for CAS80621-81-4 (American Conference of Governmental Industrial Hygienists, 2010):
    1) Not Listed

    B) NIOSH REL and IDLH Values for CAS80621-81-4 (National Institute for Occupational Safety and Health, 2007):
    1) Not Listed

    C) Carcinogenicity Ratings for CAS80621-81-4 :
    1) ACGIH (American Conference of Governmental Industrial Hygienists, 2010): Not Listed
    2) EPA (U.S. Environmental Protection Agency, 2011): Not Listed
    3) IARC (International Agency for Research on Cancer (IARC), 2016; International Agency for Research on Cancer, 2015; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010a; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2008; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2007; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2006; IARC, 2004): Not Listed
    4) NIOSH (National Institute for Occupational Safety and Health, 2007): Not Listed
    5) MAK (DFG, 2002): Not Listed
    6) NTP (U.S. Department of Health and Human Services, Public Health Service, National Toxicology Project ): Not Listed

    D) OSHA PEL Values for CAS80621-81-4 (U.S. Occupational Safety, and Health Administration (OSHA), 2010):
    1) Not Listed

Toxicity Information

    7.7.1) TOXICITY VALUES
    A) LD50- (ORAL)RAT:
    1) Greater than 2 grams/kilogram (RTECS, 2004)

Pharmacology Toxicology

Pharmacologic Mechanism

    A) Rifaximin is a product of synthesis of rifamycin, an antibiotic with low gastrointestinal absorption and good antibacterial activity (Marchi et al, 1985). It acts on the beta-subunit of the deoxyribonucleic acid (DNA)-dependent ribonucleic acid (RNA) polymerase enzyme of microorganisms to inhibit RNA synthesis (Prod Info Xifaxan(TM), 2004; Gillis & Brogden, 1995).
    B) SPECTRUM OF ACTIVITY
    1) In clinical studies, rifaximin has demonstrated activity against noninvasive strains of Escherichia coli (Prod Info XIFAXAN(R) oral tablets, 2010).
    2) In vitro data indicated that the susceptibility of Gram-positive organisms to rifaximin is greater than that of Gram-negative organisms (Venturini & Marchi, 1986). Rifaximin possesses good inhibitory activity against species of Staphylococcus, Streptococcus and Enterococcus, as well as Bacillus cereus, Moraxella catarrhalis and Haemophilus influenzae. Activity is lower against species of Enterobacteriaceae, Pseudomonas, Acinetobacter, and Helicobacter species; conflicting data exist for activity against Bacteroides species (Gillis & Brogden, 1995; Venturini & Marchi, 1986).
    C) MINIMUM INHIBITORY CONCENTRATIONS
    1) Since rifaximin undergoes essentially no systemic absorption, measurable plasma drug concentrations are very low; therefore, in-vitro susceptibility data, expressed as minimum concentrations inhibitory to 50% (MIC50) or 90% (MIC90) of strains tested, may not accurately predict antibacterial activity in the gastrointestinal tract (Venturini & Marchi, 1986).
    D) RESISTANCE PATTERNS
    1) Bacterial resistance rates of 30% to 90% have been reported after 5 days of rifaximin treatment. Within 1 to 2 weeks after treatment was halted, resistance rates had generally decreased to less than 20% in most strains tested; after 12 weeks, no resistant strains were detected (Gillis & Brogden, 1995).

Physicochemical

Molecular Weight

    A) 785.9 (Prod Info Xifaxan(TM), 2004)

References

General Bibliography

    1) 40 CFR 372.28: Environmental Protection Agency - Toxic Chemical Release Reporting, Community Right-To-Know, Lower thresholds for chemicals of special concern. National Archives and Records Administration (NARA) and the Government Printing Office (GPO). Washington, DC. Final rules current as of Apr 3, 2006.
    2) 40 CFR 372.65: Environmental Protection Agency - Toxic Chemical Release Reporting, Community Right-To-Know, Chemicals and Chemical Categories to which this part applies. National Archives and Records Association (NARA) and the Government Printing Office (GPO), Washington, DC. Final rules current as of Apr 3, 2006.
    3) 49 CFR 172.101 - App. B: Department of Transportation - Table of Hazardous Materials, Appendix B: List of Marine Pollutants. National Archives and Records Administration (NARA) and the Government Printing Office (GPO), Washington, DC. Final rules current as of Aug 29, 2005.
    4) 62 FR 58840: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 1997.
    5) 65 FR 14186: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2000.
    6) 65 FR 39264: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2000.
    7) 65 FR 77866: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2000.
    8) 66 FR 21940: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2001.
    9) 67 FR 7164: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2002.
    10) 68 FR 42710: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2003.
    11) 69 FR 54144: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2004.
    12) AIHA: 2006 Emergency Response Planning Guidelines and Workplace Environmental Exposure Level Guides Handbook, American Industrial Hygiene Association, Fairfax, VA, 2006.
    13) American Conference of Governmental Industrial Hygienists : ACGIH 2010 Threshold Limit Values (TLVs(R)) for Chemical Substances and Physical Agents and Biological Exposure Indices (BEIs(R)), American Conference of Governmental Industrial Hygienists, Cincinnati, OH, 2010.
    14) Berlo JA, Debruyne HJ, & Gortz JP: A prospective study in healthy volunteers of the topical absorption of a 5% rifaximin cream. Drugs Exptl Clin Res 1994; 5:205-208.
    15) Bucci L & Palmieri GC: Double-blind, double-dummy comparison between treatment with rifaximin and lactulose in patients with medium to severe degree hepatic encephalopathy.. Curr Med Res Opin 1993; 13:109-118.
    16) DFG: List of MAK and BAT Values 2002, Report No. 38, Deutsche Forschungsgemeinschaft, Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Wiley-VCH, Weinheim, Federal Republic of Germany, 2002.
    17) Descombe JJ, Dubourg D, Picard M, et al: Pharmacokinetic study of rifaximin after oral administration in healthy volunteers. Int J Clin Pharm Res 1994; 2:51-56.
    18) EPA: Search results for Toxic Substances Control Act (TSCA) Inventory Chemicals. US Environmental Protection Agency, Substance Registry System, U.S. EPA's Office of Pollution Prevention and Toxics. Washington, DC. 2005. Available from URL: http://www.epa.gov/srs/.
    19) Gillis CJ & Brogden RN: Rifaximin a review of its antibacterial activity, pharmacokinetic properties and therapeutic potential in conditions mediated by gastrointestinal bacteria. Drugs 1995; 49:467-484.
    20) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: 1,3-Butadiene, Ethylene Oxide and Vinyl Halides (Vinyl Fluoride, Vinyl Chloride and Vinyl Bromide), 97, International Agency for Research on Cancer, Lyon, France, 2008.
    21) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol, 88, International Agency for Research on Cancer, Lyon, France, 2006.
    22) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Household Use of Solid Fuels and High-temperature Frying, 95, International Agency for Research on Cancer, Lyon, France, 2010a.
    23) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Smokeless Tobacco and Some Tobacco-specific N-Nitrosamines, 89, International Agency for Research on Cancer, Lyon, France, 2007.
    24) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Some Non-heterocyclic Polycyclic Aromatic Hydrocarbons and Some Related Exposures, 92, International Agency for Research on Cancer, Lyon, France, 2010.
    25) IARC: List of all agents, mixtures and exposures evaluated to date - IARC Monographs: Overall Evaluations of Carcinogenicity to Humans, Volumes 1-88, 1972-PRESENT. World Health Organization, International Agency for Research on Cancer. Lyon, FranceAvailable from URL: http://monographs.iarc.fr/monoeval/crthall.html. As accessed Oct 07, 2004.
    26) International Agency for Research on Cancer (IARC): IARC monographs on the evaluation of carcinogenic risks to humans: list of classifications, volumes 1-116. International Agency for Research on Cancer (IARC). Lyon, France. 2016. Available from URL: http://monographs.iarc.fr/ENG/Classification/latest_classif.php. As accessed 2016-08-24.
    27) International Agency for Research on Cancer: IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. World Health Organization. Geneva, Switzerland. 2015. Available from URL: http://monographs.iarc.fr/ENG/Classification/. As accessed 2015-08-06.
    28) Marchi E, Montecchi L, Venturini AP, et al: 4-deoxypyridol(1,2:1,2)imidazol(5,4-c)rifamycin SV derivatives. A new series of semisynthetic rifamycins with high antibacterial activity and low gastroenteric absorption. J Med Chem 1985; 28:960-963.
    29) NFPA: Fire Protection Guide to Hazardous Materials, 13th ed., National Fire Protection Association, Quincy, MA, 2002.
    30) NRC: Acute Exposure Guideline Levels for Selected Airborne Chemicals - Volume 1, Subcommittee on Acute Exposure Guideline Levels, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission of Life Sciences, National Research Council. National Academy Press, Washington, DC, 2001.
    31) NRC: Acute Exposure Guideline Levels for Selected Airborne Chemicals - Volume 2, Subcommittee on Acute Exposure Guideline Levels, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission of Life Sciences, National Research Council. National Academy Press, Washington, DC, 2002.
    32) NRC: Acute Exposure Guideline Levels for Selected Airborne Chemicals - Volume 3, Subcommittee on Acute Exposure Guideline Levels, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission of Life Sciences, National Research Council. National Academy Press, Washington, DC, 2003.
    33) NRC: Acute Exposure Guideline Levels for Selected Airborne Chemicals - Volume 4, Subcommittee on Acute Exposure Guideline Levels, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission of Life Sciences, National Research Council. National Academy Press, Washington, DC, 2004.
    34) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,2,3-Trimethylbenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2006k. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d68a&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    35) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,2,4-Trimethylbenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2006m. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d68a&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    36) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,2-Butylene Oxide (Proposed). United States Environmental Protection Agency. Washington, DC. 2008d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648083cdbb&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    37) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,2-Dibromoethane (Proposed). United States Environmental Protection Agency. Washington, DC. 2007g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064802796db&disposition=attachment&contentType=pdf. As accessed 2010-08-18.
    38) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,3,5-Trimethylbenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2006l. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d68a&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    39) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 2-Ethylhexyl Chloroformate (Proposed). United States Environmental Protection Agency. Washington, DC. 2007b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648037904e&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    40) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Acrylonitrile (Proposed). United States Environmental Protection Agency. Washington, DC. 2007c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648028e6a3&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    41) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Adamsite (Proposed). United States Environmental Protection Agency. Washington, DC. 2007h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    42) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Agent BZ (3-quinuclidinyl benzilate) (Proposed). United States Environmental Protection Agency. Washington, DC. 2007f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064803ad507&disposition=attachment&contentType=pdf. As accessed 2010-08-18.
    43) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Allyl Chloride (Proposed). United States Environmental Protection Agency. Washington, DC. 2008. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648039d9ee&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    44) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Aluminum Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    45) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Arsenic Trioxide (Proposed). United States Environmental Protection Agency. Washington, DC. 2007m. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480220305&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    46) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Automotive Gasoline Unleaded (Proposed). United States Environmental Protection Agency. Washington, DC. 2009a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7cc17&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    47) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Biphenyl (Proposed). United States Environmental Protection Agency. Washington, DC. 2005j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064801ea1b7&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    48) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Bis-Chloromethyl Ether (BCME) (Proposed). United States Environmental Protection Agency. Washington, DC. 2006n. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648022db11&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    49) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Boron Tribromide (Proposed). United States Environmental Protection Agency. Washington, DC. 2008a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064803ae1d3&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    50) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Bromine Chloride (Proposed). United States Environmental Protection Agency. Washington, DC. 2007d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648039732a&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    51) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Bromoacetone (Proposed). United States Environmental Protection Agency. Washington, DC. 2008e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064809187bf&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    52) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Calcium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    53) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Carbonyl Fluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2008b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064803ae328&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    54) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Carbonyl Sulfide (Proposed). United States Environmental Protection Agency. Washington, DC. 2007e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648037ff26&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    55) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Chlorobenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2008c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064803a52bb&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    56) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Cyanogen (Proposed). United States Environmental Protection Agency. Washington, DC. 2008f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064809187fe&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    57) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Dimethyl Phosphite (Proposed). United States Environmental Protection Agency. Washington, DC. 2009. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7cbf3&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    58) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Diphenylchloroarsine (Proposed). United States Environmental Protection Agency. Washington, DC. 2007l. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    59) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ethyl Isocyanate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648091884e&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    60) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ethyl Phosphorodichloridate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480920347&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    61) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ethylbenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2008g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064809203e7&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    62) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ethyldichloroarsine (Proposed). United States Environmental Protection Agency. Washington, DC. 2007j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    63) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Germane (Proposed). United States Environmental Protection Agency. Washington, DC. 2008j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963906&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    64) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Hexafluoropropylene (Proposed). United States Environmental Protection Agency. Washington, DC. 2006. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064801ea1f5&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    65) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ketene (Proposed). United States Environmental Protection Agency. Washington, DC. 2007. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020ee7c&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    66) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Magnesium Aluminum Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    67) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Magnesium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    68) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Malathion (Proposed). United States Environmental Protection Agency. Washington, DC. 2009k. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064809639df&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    69) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Mercury Vapor (Proposed). United States Environmental Protection Agency. Washington, DC. 2009b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a8a087&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    70) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyl Isothiocyanate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008k. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963a03&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    71) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyl Parathion (Proposed). United States Environmental Protection Agency. Washington, DC. 2008l. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963a57&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    72) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyl tertiary-butyl ether (Proposed). United States Environmental Protection Agency. Washington, DC. 2007a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064802a4985&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    73) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methylchlorosilane (Proposed). United States Environmental Protection Agency. Washington, DC. 2005. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5f4&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    74) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyldichloroarsine (Proposed). United States Environmental Protection Agency. Washington, DC. 2007i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    75) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyldichlorosilane (Proposed). United States Environmental Protection Agency. Washington, DC. 2005a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c646&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    76) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Mustard (HN1 CAS Reg. No. 538-07-8) (Proposed). United States Environmental Protection Agency. Washington, DC. 2006a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d6cb&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    77) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Mustard (HN2 CAS Reg. No. 51-75-2) (Proposed). United States Environmental Protection Agency. Washington, DC. 2006b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d6cb&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    78) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Mustard (HN3 CAS Reg. No. 555-77-1) (Proposed). United States Environmental Protection Agency. Washington, DC. 2006c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d6cb&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    79) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Tetroxide (Proposed). United States Environmental Protection Agency. Washington, DC. 2008n. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648091855b&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    80) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Trifluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2009l. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963e0c&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    81) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Parathion (Proposed). United States Environmental Protection Agency. Washington, DC. 2008o. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963e32&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    82) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Perchloryl Fluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2009c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7e268&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    83) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Perfluoroisobutylene (Proposed). United States Environmental Protection Agency. Washington, DC. 2009d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7e26a&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    84) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phenyl Isocyanate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008p. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096dd58&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    85) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phenyl Mercaptan (Proposed). United States Environmental Protection Agency. Washington, DC. 2006d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020cc0c&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    86) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phenyldichloroarsine (Proposed). United States Environmental Protection Agency. Washington, DC. 2007k. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    87) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phorate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008q. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096dcc8&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    88) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phosgene (Draft-Revised). United States Environmental Protection Agency. Washington, DC. 2009e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a8a08a&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    89) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phosgene Oxime (Proposed). United States Environmental Protection Agency. Washington, DC. 2009f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7e26d&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    90) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Potassium Cyanide (Proposed). United States Environmental Protection Agency. Washington, DC. 2009g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7cbb9&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    91) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Potassium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    92) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Propargyl Alcohol (Proposed). United States Environmental Protection Agency. Washington, DC. 2006e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020ec91&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    93) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Selenium Hexafluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2006f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020ec55&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    94) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Silane (Proposed). United States Environmental Protection Agency. Washington, DC. 2006g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d523&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    95) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Sodium Cyanide (Proposed). United States Environmental Protection Agency. Washington, DC. 2009h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7cbb9&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    96) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Sodium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    97) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Strontium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    98) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Sulfuryl Chloride (Proposed). United States Environmental Protection Agency. Washington, DC. 2006h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020ec7a&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    99) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Tear Gas (Proposed). United States Environmental Protection Agency. Washington, DC. 2008s. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096e551&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    100) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Tellurium Hexafluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2009i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7e2a1&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    101) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Tert-Octyl Mercaptan (Proposed). United States Environmental Protection Agency. Washington, DC. 2008r. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096e5c7&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    102) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Tetramethoxysilane (Proposed). United States Environmental Protection Agency. Washington, DC. 2006j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d632&disposition=attachment&contentType=pdf. As accessed 2010-08-17.
    103) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Trimethoxysilane (Proposed). United States Environmental Protection Agency. Washington, DC. 2006i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d632&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    104) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Trimethyl Phosphite (Proposed). United States Environmental Protection Agency. Washington, DC. 2009j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7d608&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    105) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Trimethylacetyl Chloride (Proposed). United States Environmental Protection Agency. Washington, DC. 2008t. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096e5cc&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    106) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Zinc Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    107) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for n-Butyl Isocyanate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008m. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064808f9591&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    108) National Institute for Occupational Safety and Health: NIOSH Pocket Guide to Chemical Hazards, U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Cincinnati, OH, 2007.
    109) National Research Council : Acute exposure guideline levels for selected airborne chemicals, 5, National Academies Press, Washington, DC, 2007.
    110) National Research Council: Acute exposure guideline levels for selected airborne chemicals, 6, National Academies Press, Washington, DC, 2008.
    111) National Research Council: Acute exposure guideline levels for selected airborne chemicals, 7, National Academies Press, Washington, DC, 2009.
    112) National Research Council: Acute exposure guideline levels for selected airborne chemicals, 8, National Academies Press, Washington, DC, 2010.
    113) Product Information: XIFAXAN(R) oral tablets, rifaximin oral tablets. Salix Pharmaceuticals (per manufacturer), Raleigh, NC, 2015.
    114) Product Information: XIFAXAN(R) oral tablets, rifaximin oral tablets. Salix Pharmaceuticals, Inc, Morrisville, NC, 2010.
    115) Product Information: Xifaxan(TM), rifaximin tablets. Salix Pharmaceuticals, Inc., Raleigh, NC, 2004.
    116) RTECS: Registry of Toxic Effects of Chemical Substances.. National Institute for Occupational Safety and Health. Cincinnati, OH (Internet Version). Edition expires 2004; provided by Truven Health Analytics Inc., Greenwood Village, CO.
    117) U.S. Department of Energy, Office of Emergency Management: Protective Action Criteria (PAC) with AEGLs, ERPGs, & TEELs: Rev. 26 for chemicals of concern. U.S. Department of Energy, Office of Emergency Management. Washington, DC. 2010. Available from URL: http://www.hss.doe.gov/HealthSafety/WSHP/Chem_Safety/teel.html. As accessed 2011-06-27.
    118) U.S. Department of Health and Human Services, Public Health Service, National Toxicology Project : 11th Report on Carcinogens. U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. Washington, DC. 2005. Available from URL: http://ntp.niehs.nih.gov/INDEXA5E1.HTM?objectid=32BA9724-F1F6-975E-7FCE50709CB4C932. As accessed 2011-06-27.
    119) U.S. Environmental Protection Agency: Discarded commercial chemical products, off-specification species, container residues, and spill residues thereof. Environmental Protection Agency's (EPA) Resource Conservation and Recovery Act (RCRA); List of hazardous substances and reportable quantities 2010b; 40CFR(261.33, e-f):77-.
    120) U.S. Environmental Protection Agency: Integrated Risk Information System (IRIS). U.S. Environmental Protection Agency. Washington, DC. 2011. Available from URL: http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showSubstanceList&list_type=date. As accessed 2011-06-21.
    121) U.S. Environmental Protection Agency: List of Radionuclides. U.S. Environmental Protection Agency. Washington, DC. 2010a. Available from URL: http://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol27/pdf/CFR-2010-title40-vol27-sec302-4.pdf. As accessed 2011-06-17.
    122) U.S. Environmental Protection Agency: List of hazardous substances and reportable quantities. U.S. Environmental Protection Agency. Washington, DC. 2010. Available from URL: http://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol27/pdf/CFR-2010-title40-vol27-sec302-4.pdf. As accessed 2011-06-17.
    123) U.S. Environmental Protection Agency: The list of extremely hazardous substances and their threshold planning quantities (CAS Number Order). U.S. Environmental Protection Agency. Washington, DC. 2010c. Available from URL: http://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol27/pdf/CFR-2010-title40-vol27-part355.pdf. As accessed 2011-06-17.
    124) U.S. Occupational Safety and Health Administration: Part 1910 - Occupational safety and health standards (continued) Occupational Safety, and Health Administration's (OSHA) list of highly hazardous chemicals, toxics and reactives. Subpart Z - toxic and hazardous substances. CFR 2010 2010; Vol6(SEC1910):7-.
    125) U.S. Occupational Safety, and Health Administration (OSHA): Process safety management of highly hazardous chemicals. 29 CFR 2010 2010; 29(1910.119):348-.
    126) United States Environmental Protection Agency Office of Pollution Prevention and Toxics: Acute Exposure Guideline Levels (AEGLs) for Vinyl Acetate (Proposed). United States Environmental Protection Agency. Washington, DC. 2006. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d6af&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    127) Venturini AP & Marchi E: In vitro and in vivo evaluation of L/105, a new topical intestinal rifamycin. Chemioterapia 1986; 5:257-262.
    128) Verardi S & Verardi V: Bile rifaximin concentration after oral administration in patients undergoing cholecystectomy. Farmaco 1990; 45:131-135.