Contact Us    Contact Us     |     Feedback
MOBILE VIEW  | 

ETHINAMATE

Export To Excel

Classification   |    Detailed evidence-based information

Substances Included Synonyms

Therapeutic Toxic Class

    A) Ethinamate is a relatively short acting sedative, hypnotic drug that has tranquilizing but not muscle-relaxant properties (Foye, 1974).

Specific Substances

    1) 1-ethynl-1-cyclohexyl carbamate
    2) 1-ethynylcyclohexyl carbamate
    3) Carbamaic acid, 1-ethynylcyclohexyl ester
    4) Ethynylcyclohexyl carbamate
    5) Valmid(R)
    6) Molecular Formula: C9-H13-N-O2
    7) CAS 126-52-3

Available Forms Sources

    A) FORMS
    1) Brand names for ethinamate include Valmid (R) in the United States (JEF Reynolds , 1989).

Overview

Laboratory Monitoring

    A) No specific laboratories are required. Ethinamate may be measured in the serum, and its metabolites in the urine.
    B) If respiratory depression is severe, arterial blood gases may be required.

Treatment Overview

    0.4.2) ORAL/PARENTERAL EXPOSURE
    A) EMESIS: Ipecac-induced emesis is not recommended because of the potential for CNS depression.
    B) GASTRIC LAVAGE: Consider after ingestion of a potentially life-threatening amount of poison if it can be performed soon after ingestion (generally within 1 hour). Protect airway by placement in the head down left lateral decubitus position or by endotracheal intubation. Control any seizures first.
    1) CONTRAINDICATIONS: Loss of airway protective reflexes or decreased level of consciousness in unintubated patients; following ingestion of corrosives; hydrocarbons (high aspiration potential); patients at risk of hemorrhage or gastrointestinal perforation; and trivial or non-toxic ingestion.
    C) ACTIVATED CHARCOAL: Administer charcoal as a slurry (240 mL water/30 g charcoal). Usual dose: 25 to 100 g in adults/adolescents, 25 to 50 g in children (1 to 12 years), and 1 g/kg in infants less than 1 year old.
    D) HYPOTENSION: Infuse 10 to 20 mL/kg isotonic fluid. If hypotension persists, administer dopamine (5 to 20 mcg/kg/min) or norepinephrine (ADULT: begin infusion at 0.5 to 1 mcg/min; CHILD: begin infusion at 0.1 mcg/kg/min); titrate to desired response.
    E) Provide adequate respiratory and cardiovascular support.

Range Of Toxicity

    A) As little as 15 grams has been lethal, while up to 28 grams has been survived.

Life Support

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

Clinical Effects

    0.2.1) SUMMARY OF EXPOSURE
    A) WITH POISONING/EXPOSURE
    1) The toxicity of ethinamate is similar to that of the barbiturates. The primary toxicity is CNS and respiratory depression, sometimes accompanied by hypotension.
    0.2.5) CARDIOVASCULAR
    A) WITH POISONING/EXPOSURE
    1) Hypotension may be seen in severe cases.
    0.2.6) RESPIRATORY
    A) WITH POISONING/EXPOSURE
    1) Respiratory depression may be seen, similar to the barbiturates.
    0.2.7) NEUROLOGIC
    A) WITH THERAPEUTIC USE
    1) Therapeutically, children may experience a paradoxical excitement.
    B) WITH POISONING/EXPOSURE
    1) The primary effect in overdose is coma.
    0.2.8) GASTROINTESTINAL
    A) WITH THERAPEUTIC USE
    1) Vomiting has been seen with therapeutic dosing.
    0.2.10) GENITOURINARY
    A) ANIMAL AND LAB STUDIES - Ethinamate has been shown to be porphyrinogenic in animals and in some in vitro test systems.
    0.2.14) DERMATOLOGIC
    A) WITH THERAPEUTIC USE
    1) Various skin rashes have been reported with therapeutic use. Thrombocytopenia purpura has been noted as a hypersensitivity reaction.
    0.2.20) REPRODUCTIVE
    A) At the time of this review, no data were available to assess the teratogenic potential of this agent.
    B) Pregnancy Category C
    0.2.21) CARCINOGENICITY
    A) At the time of this review, no data were available to assess the carcinogenic or mutagenic potential of this agent.

Clinical Effects

Summary Of Exposure

    A) WITH POISONING/EXPOSURE
    1) The toxicity of ethinamate is similar to that of the barbiturates. The primary toxicity is CNS and respiratory depression, sometimes accompanied by hypotension.

Vital Signs

    3.3.2) RESPIRATIONS
    A) WITH POISONING/EXPOSURE
    1) RESPIRATORY DEPRESSION similar to that seen with the barbiturates would be expected in overdose (Prod Info, 1989).
    3.3.3) TEMPERATURE
    A) WITH THERAPEUTIC USE
    1) FEVER associated with hypersensitivity reactions has been reported (JEF Reynolds , 1989).
    3.3.4) BLOOD PRESSURE
    A) WITH POISONING/EXPOSURE
    1) HYPOTENSION might be expected in severe cases of poisoning (Prod Info, 1989).

Cardiovascular

    3.5.1) SUMMARY
    A) WITH POISONING/EXPOSURE
    1) Hypotension may be seen in severe cases.
    3.5.2) CLINICAL EFFECTS
    A) HYPOTENSIVE EPISODE
    1) WITH POISONING/EXPOSURE
    a) Hypotension might be expected in severe cases of poisoning (Davis et al, 1959) Prod Info, 1989).

Respiratory

    3.6.1) SUMMARY
    A) WITH POISONING/EXPOSURE
    1) Respiratory depression may be seen, similar to the barbiturates.
    3.6.2) CLINICAL EFFECTS
    A) ACUTE RESPIRATORY INSUFFICIENCY
    1) WITH POISONING/EXPOSURE
    a) Respiratory depression similar to that seen with the barbiturates would be expected in overdose (Davis et al, 1959) Prod Info, 1989).

Neurologic

    3.7.1) SUMMARY
    A) WITH THERAPEUTIC USE
    1) Therapeutically, children may experience a paradoxical excitement.
    B) WITH POISONING/EXPOSURE
    1) The primary effect in overdose is coma.
    3.7.2) CLINICAL EFFECTS
    A) COMA
    1) WITH POISONING/EXPOSURE
    a) Coma would be the normal response to overdose with this agent (Prod Info, 1989).
    B) CENTRAL STIMULANT ADVERSE REACTION
    1) WITH THERAPEUTIC USE
    a) Excitement is a complication sometimes seen with therapeutic doses in children (JEF Reynolds , 1989).

Gastrointestinal

    3.8.1) SUMMARY
    A) WITH THERAPEUTIC USE
    1) Vomiting has been seen with therapeutic dosing.
    3.8.2) CLINICAL EFFECTS
    A) VOMITING
    1) WITH THERAPEUTIC USE
    a) Gastrointestinal upset has occurred with therapeutic use (JEF Reynolds , 1989).

Genitourinary

    3.10.1) SUMMARY
    A) ANIMAL AND LAB STUDIES - Ethinamate has been shown to be porphyrinogenic in animals and in some in vitro test systems.
    3.10.3) ANIMAL EFFECTS
    A) ANIMAL STUDIES
    1) PORPHYRIA
    a) ANIMAL AND LAB STUDIES - Ethinamate has been shown to be porphyrinogenic in animals and in some in vitro test systems (JEF Reynolds , 1989).

Dermatologic

    3.14.1) SUMMARY
    A) WITH THERAPEUTIC USE
    1) Various skin rashes have been reported with therapeutic use. Thrombocytopenia purpura has been noted as a hypersensitivity reaction.
    3.14.2) CLINICAL EFFECTS
    A) ERUPTION
    1) WITH THERAPEUTIC USE
    a) Various skin rashes have been reported with therapeutic use (JEF Reynolds , 1989).
    B) THROMBOCYTOPENIC PURPURA
    1) WITH THERAPEUTIC USE
    a) Thrombocytopenic purpura has been a rare side effect with therapeutic use (JEF Reynolds , 1989).

Reproductive

    3.20.1) SUMMARY
    A) At the time of this review, no data were available to assess the teratogenic potential of this agent.
    B) Pregnancy Category C
    3.20.2) TERATOGENICITY
    A) LACK OF INFORMATION
    1) At the time of this review, no data were available to assess the teratogenic potential of this agent.
    3.20.3) EFFECTS IN PREGNANCY
    A) PREGNANCY CATEGORY
    ETHINAMATEC
    Reference: Briggs et al, 1998

Carcinogenicity

    3.21.2) SUMMARY/HUMAN
    A) At the time of this review, no data were available to assess the carcinogenic or mutagenic potential of this agent.
    3.21.3) HUMAN STUDIES
    A) LACK OF INFORMATION
    1) At the time of this review, no data were available to assess the carcinogenic or mutagenic potential of this agent.

Laboratory Monitoring

Monitoring Parameters Levels

    4.1.1) SUMMARY
    A) No specific laboratories are required. Ethinamate may be measured in the serum, and its metabolites in the urine.
    B) If respiratory depression is severe, arterial blood gases may be required.
    4.1.2) SERUM/BLOOD
    A) BLOOD/SERUM CHEMISTRY
    1) Ethinamate is generally sought in the serum, and is generally part of a laboratory's coma screen (Ellenhorn & Barceloux, 1988).
    B) ACID/BASE
    1) If the patient has significant respiratory depression, arterial blood gases may be indicated.
    4.1.3) URINE
    A) URINARY LEVELS
    1) 4-hydroxyethinamate is found in the urine.

Methods

    A) MULTIPLE ANALYTICAL METHODS
    1) Ethinamate can be determined by various methods, including gas chromatography (Kulpman, 1979; (Kleber et al, 1977), through titrimetric determination using organic brominating agents (el Brashy et al, 1988) Walash et al, 1985), and by colorimetric determination by formation of silver acetylides (Rizk et al, 1980). Maurer et al (1990) described a gas chromatography/mass spectrometry procedure to identify barbiturates and other sedative-hypnotics including ethinamate in urine.
    B) OTHER
    1) Ethinamate is generally sought in the serum, the metabolite trans-4-hydroxyethinamate in the urine (Keber et al, 1977).

Treatment

Life Support

    A) Support respiratory and cardiovascular function.

Monitoring

    A) No specific laboratories are required. Ethinamate may be measured in the serum, and its metabolites in the urine.
    B) If respiratory depression is severe, arterial blood gases may be required.

Oral Exposure

    6.5.1) PREVENTION OF ABSORPTION/PREHOSPITAL
    A) EMESIS/NOT RECOMMENDED -
    1) Emesis is NOT recommended because CNS depression may be seen within 15 to 30 minutes.
    B) ACTIVATED CHARCOAL -
    1) PREHOSPITAL ACTIVATED CHARCOAL ADMINISTRATION
    a) Consider prehospital administration of activated charcoal as an aqueous slurry in patients with a potentially toxic ingestion who are awake and able to protect their airway. Activated charcoal is most effective when administered within one hour of ingestion. Administration in the prehospital setting has the potential to significantly decrease the time from toxin ingestion to activated charcoal administration, although it has not been shown to affect outcome (Alaspaa et al, 2005; Thakore & Murphy, 2002; Spiller & Rogers, 2002).
    1) In patients who are at risk for the abrupt onset of seizures or mental status depression, activated charcoal should not be administered in the prehospital setting, due to the risk of aspiration in the event of spontaneous emesis.
    2) The addition of flavoring agents (cola drinks, chocolate milk, cherry syrup) to activated charcoal improves the palatability for children and may facilitate successful administration (Guenther Skokan et al, 2001; Dagnone et al, 2002).
    2) CHARCOAL DOSE
    a) Use a minimum of 240 milliliters of water per 30 grams charcoal (FDA, 1985). Optimum dose not established; usual dose is 25 to 100 grams in adults and adolescents; 25 to 50 grams in children aged 1 to 12 years (or 0.5 to 1 gram/kilogram body weight) ; and 0.5 to 1 gram/kilogram in infants up to 1 year old (Chyka et al, 2005).
    1) Routine use of a cathartic with activated charcoal is NOT recommended as there is no evidence that cathartics reduce drug absorption and cathartics are known to cause adverse effects such as nausea, vomiting, abdominal cramps, electrolyte imbalances and occasionally hypotension (None Listed, 2004).
    b) ADVERSE EFFECTS/CONTRAINDICATIONS
    1) Complications: emesis, aspiration (Chyka et al, 2005). Aspiration may be complicated by acute respiratory failure, ARDS, bronchiolitis obliterans or chronic lung disease (Golej et al, 2001; Graff et al, 2002; Pollack et al, 1981; Harris & Filandrinos, 1993; Elliot et al, 1989; Rau et al, 1988; Golej et al, 2001; Graff et al, 2002). Refer to the ACTIVATED CHARCOAL/TREATMENT management for further information.
    2) Contraindications: unprotected airway (increases risk/severity of aspiration) , nonfunctioning gastrointestinal tract, uncontrolled vomiting, and ingestion of most hydrocarbons (Chyka et al, 2005).
    6.5.2) PREVENTION OF ABSORPTION
    A) EMESIS/NOT RECOMMENDED
    1) Because CNS depression may be seen within 15 to 30 minutes, emesis is not recommended.
    B) ACTIVATED CHARCOAL
    1) CHARCOAL ADMINISTRATION
    a) Consider administration of activated charcoal after a potentially toxic ingestion (Chyka et al, 2005). Administer charcoal as an aqueous slurry; most effective when administered within one hour of ingestion.
    2) CHARCOAL DOSE
    a) Use a minimum of 240 milliliters of water per 30 grams charcoal (FDA, 1985). Optimum dose not established; usual dose is 25 to 100 grams in adults and adolescents; 25 to 50 grams in children aged 1 to 12 years (or 0.5 to 1 gram/kilogram body weight) ; and 0.5 to 1 gram/kilogram in infants up to 1 year old (Chyka et al, 2005).
    1) Routine use of a cathartic with activated charcoal is NOT recommended as there is no evidence that cathartics reduce drug absorption and cathartics are known to cause adverse effects such as nausea, vomiting, abdominal cramps, electrolyte imbalances and occasionally hypotension (None Listed, 2004).
    b) ADVERSE EFFECTS/CONTRAINDICATIONS
    1) Complications: emesis, aspiration (Chyka et al, 2005). Aspiration may be complicated by acute respiratory failure, ARDS, bronchiolitis obliterans or chronic lung disease (Golej et al, 2001; Graff et al, 2002; Pollack et al, 1981; Harris & Filandrinos, 1993; Elliot et al, 1989; Rau et al, 1988; Golej et al, 2001; Graff et al, 2002). Refer to the ACTIVATED CHARCOAL/TREATMENT management for further information.
    2) Contraindications: unprotected airway (increases risk/severity of aspiration) , nonfunctioning gastrointestinal tract, uncontrolled vomiting, and ingestion of most hydrocarbons (Chyka et al, 2005).
    C) GASTRIC LAVAGE
    1) INDICATIONS: Consider gastric lavage with a large-bore orogastric tube (ADULT: 36 to 40 French or 30 English gauge tube {external diameter 12 to 13.3 mm}; CHILD: 24 to 28 French {diameter 7.8 to 9.3 mm}) after a potentially life threatening ingestion if it can be performed soon after ingestion (generally within 60 minutes).
    a) Consider lavage more than 60 minutes after ingestion of sustained-release formulations and substances known to form bezoars or concretions.
    2) PRECAUTIONS:
    a) SEIZURE CONTROL: Is mandatory prior to gastric lavage.
    b) AIRWAY PROTECTION: Place patients in the head down left lateral decubitus position, with suction available. Patients with depressed mental status should be intubated with a cuffed endotracheal tube prior to lavage.
    3) LAVAGE FLUID:
    a) Use small aliquots of liquid. Lavage with 200 to 300 milliliters warm tap water (preferably 38 degrees Celsius) or saline per wash (in older children or adults) and 10 milliliters/kilogram body weight of normal saline in young children(Vale et al, 2004) and repeat until lavage return is clear.
    b) The volume of lavage return should approximate amount of fluid given to avoid fluid-electrolyte imbalance.
    c) CAUTION: Water should be avoided in young children because of the risk of electrolyte imbalance and water intoxication. Warm fluids avoid the risk of hypothermia in very young children and the elderly.
    4) COMPLICATIONS:
    a) Complications of gastric lavage have included: aspiration pneumonia, hypoxia, hypercapnia, mechanical injury to the throat, esophagus, or stomach, fluid and electrolyte imbalance (Vale, 1997). Combative patients may be at greater risk for complications (Caravati et al, 2001).
    b) Gastric lavage can cause significant morbidity; it should NOT be performed routinely in all poisoned patients (Vale, 1997).
    5) CONTRAINDICATIONS:
    a) Loss of airway protective reflexes or decreased level of consciousness if patient is not intubated, following ingestion of corrosive substances, hydrocarbons (high aspiration potential), patients at risk of hemorrhage or gastrointestinal perforation, or trivial or non-toxic ingestion.
    6.5.3) TREATMENT
    A) HYPOTENSIVE EPISODE
    1) SUMMARY
    a) Infuse 10 to 20 milliliters/kilogram of isotonic fluid and keep the patient supine. If hypotension persists, administer dopamine or norepinephrine. Consider central venous pressure monitoring to guide further fluid therapy.
    2) DOPAMINE
    a) DOSE: Begin at 5 micrograms per kilogram per minute progressing in 5 micrograms per kilogram per minute increments as needed (Prod Info dopamine hcl, 5% dextrose IV injection, 2004). If hypotension persists, dopamine may need to be discontinued and a more potent vasoconstrictor (eg, norepinephrine) should be considered (Prod Info dopamine hcl, 5% dextrose IV injection, 2004).
    b) CAUTION: If ventricular dysrhythmias occur, decrease rate of administration (Prod Info dopamine hcl, 5% dextrose IV injection, 2004). Extravasation may cause local tissue necrosis, administration through a central venous catheter is preferred (Prod Info dopamine hcl, 5% dextrose IV injection, 2004).
    B) SUPPORT
    1) Provide adequate respiratory and cardiovascular support.
    2) Monitor pulse oximetry and/or ABGs, chest x-ray, and pulmonary function tests in symptomatic patients.

Enhanced Elimination

    A) HEMODIALYSIS
    1) Hemodilaysis may be of some value in the treatment of severe poisoning (JEF Reynolds , 1989), and has been tried clinically (Davis et al, 1959).

Range Of Toxicity

Summary

    A) As little as 15 grams has been lethal, while up to 28 grams has been survived.

Therapeutic Dose

    7.2.1) ADULT
    A) GENERAL
    1) The usual adult dose is 500 milligrams to 1 gram at bedtime (JEF Reynolds , 1989).

Minimum Lethal Exposure

    A) ACUTE
    1) As little as 15 grams of ethinamate has been lethal (Davis et al, 1959).

Maximum Tolerated Exposure

    A) ACUTE
    1) A patient has survived up to 28 grams (Davis et al, 1959).

Serum Plasma Blood Concentrations

    7.5.2) TOXIC CONCENTRATIONS
    A) TOXIC CONCENTRATION LEVELS
    1) CASE REPORTS
    a) In two fatalities, the postmortem blood concentrations were 100 milligrams/liter and 200 milligrams/liter (Gottschalk & Cravey, 1980).

Pharmacology Toxicology

Pharmacologic Mechanism

    A) Electroencephlograms done on patients taking this drug show slow activity and spindles similar to those noted in patients taking barbiturates, indicating that the mechanism of action may be similar (Foye, 1974).

Physicochemical

Physical Characteristics

    A) This compound exists as a white powder almost without odor (JEF Reynolds , 1989).

Molecular Weight

    A) 167.2

References

General Bibliography

    1) Alaspaa AO, Kuisma MJ, Hoppu K, et al: Out-of-hospital administration of activated charcoal by emergency medical services. Ann Emerg Med 2005; 45:207-12.
    2) Caravati EM, Knight HH, & Linscott MS: Esophageal laceration and charcoal mediastinum complicating gastric lavage. J Emerg Med 2001; 20:273-276.
    3) Chyka PA, Seger D, Krenzelok EP, et al: Position paper: Single-dose activated charcoal. Clin Toxicol (Phila) 2005; 43(2):61-87.
    4) Clifford JM, Cookson JH, & Wickham PE: Absorption and clearance of secobarbital, heptabarbital, methaqualone, and ethinamate. Clin Pharmacol Ther 1974; 16:376.
    5) Dagnone D, Matsui D, & Rieder MJ: Assessment of the palatability of vehicles for activated charcoal in pediatric volunteers. Pediatr Emerg Care 2002; 18:19-21.
    6) Davis RP, Blythe WB, & Newtgon M: The treatment of intoxication with ethynyl-cyclohexyl carbamate (Valmid) by extracorporeal hemodialysis: a case report. Yale J Biol Med 1959; 32:192-196.
    7) Ellenhorn MJ & Barceloux DG: Medical Toxicology: Diagnosis and Treatment of Human Poisoning, Elsevier, New York, NY, 1988.
    8) Elliot CG, Colby TV, & Kelly TM: Charcoal lung. Bronchiolitis obliterans after aspiration of activated charcoal. Chest 1989; 96:672-674.
    9) Essig CF: JAMA 1966; 196:714.
    10) FDA: Poison treatment drug product for over-the-counter human use; tentative final monograph. FDA: Fed Register 1985; 50:2244-2262.
    11) Foye WO: Principles of Medicinal Chemistry, Lea & Febiger, Philadelphia, PA, 1974.
    12) Fuller RW, Ratbun RC, & Parli CJ: Inhibition of drug metabolism by fluoxetine. Res Commun Chem Pathol Pharmacol 1976; 13:353-356.
    13) Golej J, Boigner H, Burda G, et al: Severe respiratory failure following charcoal application in a toddler. Resuscitation 2001; 49:315-318.
    14) Gottschalk LA & Cravey RH: Toxicological and Pathological Studies on Psychoactive Drug-Involved Deaths, Biomedical Publications, Davis, CA, 1980, pp 232-233.
    15) Graff GR, Stark J, & Berkenbosch JW: Chronic lung disease after activated charcoal aspiration. Pediatrics 2002; 109:959-961.
    16) Guenther Skokan E, Junkins EP, & Corneli HM: Taste test: children rate flavoring agents used with activated charcoal. Arch Pediatr Adolesc Med 2001; 155:683-686.
    17) Harris CR & Filandrinos D: Accidental administration of activated charcoal into the lung: aspiration by proxy. Ann Emerg Med 1993; 22:1470-1473.
    18) JEF Reynolds : Martindale: The Extra Pharmacopoeia (CD-ROM Version). The Pharmaceutical Press. London, UK (Internet Version). Edition expires 1989; provided by Truven Health Analytics Inc., Greenwood Village, CO.
    19) Kleber JW, Bechtol LD, & Brunson MK: GLC determination of ethinamate and its hydroxy derivative in biological fluids. J Pharm Sci 1977; 66:992-994.
    20) McMahon RE: The in vivo hydroxylation of 1-ethynylcyclohexyl carbamate. II. The orientation of hydroxylation. J Org Chem 1959; 24:1834-1837.
    21) McMahon RE: The in vivo hydroxylation of 1-ethynylcyclohexyl carbamate. J Am Chem Soc 1958; 80:411-414.
    22) None Listed: Position paper: cathartics. J Toxicol Clin Toxicol 2004; 42(3):243-253.
    23) Pollack MM, Dunbar BS, & Holbrook PR: Aspiration of activated charcoal and gastric contents. Ann Emerg Med 1981; 10:528-529.
    24) Preuss FR & Willig G: Die Struktur einiger renaler Ausscheidungspodukte des 1-Athinyl-cyclohexylcarbamat-(1). Arzneim Forsch 1963; 13:234-237.
    25) Product Information: dopamine hcl, 5% dextrose IV injection, dopamine hcl, 5% dextrose IV injection. Hospira,Inc, Lake Forest, IL, 2004.
    26) Rau NR, Nagaraj MV, Prakash PS, et al: Fatal pulmonary aspiration of oral activated charcoal. Br Med J 1988; 297:918-919.
    27) Rizk MS, Walash MI, & El-Brashy A: Colorimetric determination of acetylenic hypnotics by formation of silver acetylides. J Assoc Off Anal Chem 1980; 63:88-90.
    28) Speirs CF, Virden S, & Scott DF: A simultaneous plasma level and EEG assessment of an oral hypnotic (ethinamate). Eur J Pharmacol 1972; 20:127-129.
    29) Spiller HA & Rogers GC: Evaluation of administration of activated charcoal in the home. Pediatrics 2002; 108:E100.
    30) Thakore S & Murphy N: The potential role of prehospital administration of activated charcoal. Emerg Med J 2002; 19:63-65.
    31) Vale JA, Kulig K, American Academy of Clinical Toxicology, et al: Position paper: Gastric lavage. J Toxicol Clin Toxicol 2004; 42:933-943.
    32) Vale JA: Position Statement: gastric lavage. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists. J Toxicol Clin Toxicol 1997; 35:711-719.
    33) el Brashy A, Belal F, & Walash MI: Titrimetric determination of acetylenic hypnotics using organic brominating agents. Pharm Weekbl (Sci) 1988; 10:90-92.