6.5.1) PREVENTION OF ABSORPTION/PREHOSPITAL
A) 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) SUMMARY 1) Goals are to remove, detoxify, or prevent absorption of ingested substances.
2) UNIVERSAL ANTIDOTE: Non-activated charcoal, tannic acid, and magnesium oxide or hydroxide should NOT be used.
B) ACTIVATED CHARCOAL 1) There are very few drugs which are not adsorbed by activated charcoal (Hayden & Comstock, 1975; Temple & Mancini, 1980). Among them are alkali and acids, ferrous sulfate, lithium (Linakis et al, 1989) and N-methyl carbamate (Greensher et al, 1979). 2) CONTRAINDICATIONS: Charcoal should not be administered in cases of a simple caustic ingestion because it will obscure endoscopic evaluation or in hydrocarbon ingestion because of the risk of vomiting and aspiration, unless the major toxicologic risk is from another coingestant. 3) 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.
4) 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 a) A large amount of poison has been ingested with the potential to cause serious toxicity; recent ingestion. b) Advantages of lavage include its ability to potentially remove pills and pill fragments. Lavage must be performed within a short period of time following ingestion or its effectiveness decreases dramatically; some authors speculate that it may force gastric content beyond the pylorus (Saetta et al, 1991). c) Potential complications include vomiting, pulmonary aspiration, epistaxis, and laryngospasm. d) 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). 1) Consider lavage more than 60 minutes after ingestion of sustained-release formulations and substances known to form bezoars or concretions.
e) PRECAUTIONS: 1) SEIZURE CONTROL: Is mandatory prior to gastric lavage.
2) 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.
f) LAVAGE FLUID: 1) 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.
2) The volume of lavage return should approximate amount of fluid given to avoid fluid-electrolyte imbalance.
3) 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.
g) COMPLICATIONS: 1) 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).
2) Gastric lavage can cause significant morbidity; it should NOT be performed routinely in all poisoned patients (Vale, 1997).
h) CONTRAINDICATIONS: 1) 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.
i) CONTRAINDICATIONS: Gastric lavage should not be performed in cases of caustic ingestion because of the risk of GI perforation, or in hydrocarbon ingestion because of the risk of aspiration, unless the major toxicologic risk is from another coingestant. It is also contraindicated if an acid of alkali or suspected (Boyle et al, 2009). D) CATHARTIC 1) Use of cathartics is NOT routinely recommended. There has been documented toxicity from overdoses of magnesium sulfate (Outerbridge et al, 1973), sodium phosphate (Fassler et al, 1985; Garcia-Webb et al, 1984; Smilkstein et al, 1988), magnesium citrate (Jones et al, 1986), and sorbitol (Farley, 1986; Caldwell et al, 1987; Geffner & Opas, 1980).
E) MULTIPLE DOSE ACTIVATED CHARCOAL 1) Serial doses of charcoal have been useful for several drugs including phenobarbital, carbamazepine, quinine, theophylline, and dapsone (Levy, 1982; Vale et al, 1999). Multiple dose charcoal has not been shown to affect survival or outcome for any toxin. Routine use is NOT recommended. 2) MULTIPLE DOSE ACTIVATED CHARCOAL a) ADULT DOSE: Optimal dose not established. After an initial dose of 50 to 100 grams of activated charcoal, subsequent doses may be administered every 1, 2 or 4 hours at a dose equivalent to 12.5 grams/hour (Vale et al, 1999), do not exceed: 0.5 g/kg charcoal every 2 hours (Ghannoum & Gosselin, 2013; Mauro et al, 1994). There is some evidence that smaller more frequent doses are more effective at enhancing drug elimination than larger less frequent doses (Park et al, 1983; Ilkhanipour et al, 1992). PEDIATRIC DOSE: Optimal dose not established. After an initial dose of 25 to 50 grams in children aged 1 to 12 years (or 0.5 to 1 gram/kilogram body weight) (Chyka & Seger, 1997), subsequent doses may be administered every 1, 2 or 4 hours (Vale et al, 1999) in a dose equivalent to 6.25 grams/hour in children 1 to 12 years old.
b) Activated charcoal should be continued until the patient's clinical and laboratory parameters, including drug concentrations if available, are improving (Vale et al, 1999). The patient should be frequently assessed for the ability to protect the airway and evidence of decreased peristalsis or intestinal obstruction.
c) Use of cathartics has not been shown to increase drug elimination and may increase the likelihood of vomiting. Routine coadministration of a cathartic is NOT recommended (Vale et al, 1999).
d) AGENTS AMENABLE TO MDAC THERAPY: The following properties of a drug that are likely to allow MDAC therapy to be effective include: small volume of distribution, low protein binding, prolonged half-life, low intrinsic clearance, and a nonionized state at physiologic pH (Chyka, 1995; Ghannoum & Gosselin, 2013).
e) Vomiting is a common adverse effect; antiemetics may be necessary.
f) CONTRAINDICATIONS: Absolute contraindications include an unprotected airway, intestinal obstruction, a gastrointestinal tract that is not intact and agents that may increase the risk of aspiration (eg, hydrocarbons). Relative contraindications include decreased peristalsis (eg, decreased bowel sounds, abdominal distention, ileus, severe constipation) (Vale et al, 1999; Mauro et al, 1994).
g) COMPLICATIONS: Include constipation, intestinal bleeding, bowel obstruction, appendicitis, charcoal bezoars, and aspiration which may be complicated by acute respiratory failure, adult respiratory distress syndrome or bronchiolitis obliterans (Ghannoum & Gosselin, 2013; Ray et al, 1988; Atkinson et al, 1992; Gomez et al, 1994; Mizutani et al, 1991; Pollack et al, 1981; Harris & Filandrinos, 1993; Elliot et al, 1989; Mina et al, 2002; Harsch, 1986; Rau et al, 1988; Golej et al, 2001; Graff et al, 2002).
F) WHOLE BOWEL IRRIGATION 1) INDICATIONS: May be useful for ingestions of sustained release or enteric coated products, substances not well adsorbed by charcoal, unruptured packets containing illicit drugs or other toxins, or in patients with substantial ingestions presenting late after overdose. a) WHOLE BOWEL IRRIGATION/INDICATIONS: Whole bowel irrigation with a polyethylene glycol balanced electrolyte solution appears to be a safe means of gastrointestinal decontamination. It is particularly useful when sustained release or enteric coated formulations, substances not adsorbed by activated charcoal, or substances known to form concretions or bezoars are involved in the overdose. 1) Volunteer studies have shown significant decreases in the bioavailability of ingested drugs after whole bowel irrigation (Tenenbein et al, 1987; Kirshenbaum et al, 1989; Smith et al, 1991). There are no controlled clinical trials evaluating the efficacy of whole bowel irrigation in overdose.
b) CONTRAINDICATIONS: This procedure should not be used in patients who are currently or are at risk for rapidly becoming obtunded, comatose, or seizing until the airway is secured by endotracheal intubation. Whole bowel irrigation should not be used in patients with bowel obstruction, bowel perforation, megacolon, ileus, uncontrolled vomiting, significant gastrointestinal bleeding, hemodynamic instability or inability to protect the airway (Tenenbein et al, 1987). c) ADMINISTRATION: Polyethylene glycol balanced electrolyte solution (e.g. Colyte(R), Golytely(R)) is taken orally or by nasogastric tube. The patient should be seated and/or the head of the bed elevated to at least a 45 degree angle (Tenenbein et al, 1987). Optimum dose not established. ADULT: 2 liters initially followed by 1.5 to 2 liters per hour. CHILDREN 6 to 12 years: 1000 milliliters/hour. CHILDREN 9 months to 6 years: 500 milliliters/hour. Continue until rectal effluent is clear and there is no radiographic evidence of toxin in the gastrointestinal tract. d) ADVERSE EFFECTS: Include nausea, vomiting, abdominal cramping, and bloating. Fluid and electrolyte status should be monitored, although severe fluid and electrolyte abnormalities have not been reported, minor electrolyte abnormalities may develop. Prolonged periods of irrigation may produce a mild metabolic acidosis. Patients with compromised airway protection are at risk for aspiration. 6.5.3) TREATMENT
A) SUPPORT 1) Establish respiration and create an artificial airway, if necessary. Check adequacy of tidal volume. Establish venous access; preferably 2 large bore peripheral intravenous catheters. 2) Treat hypotension with fluids, try to avoid vasopressors if possible. If a patient does not respond to fluids, consider the possible agent ingested to select the ideal vasopressor. An alpha antagonism, such as olanzapine (an atypical antipsychotic) can respond to a direct alpha stimulation (ie, phenylephrine); a tricyclic antidepressant thought to deplete biogenic amines may respond to a mixed alpha agonist (ie, dopamine) or a direct alpha agonist (ie, norepinephrine) may be needed (Boyle et al, 2009). 3) CARDIOPULMONARY RESUSCITATION a) Although controversial and individual considerations exist, aggressive, prolonged cardiopulmonary resuscitation should be considered in the poisoned patient. Unlike the typical emergency patient with cardiac arrest due to ischemic heart disease who do not respond to 30 to 60 minutes of resuscitation efforts, many poisoned patients are younger and if supported usually recover (Boyle et al, 2009; Little, 2009)
b) Antidotes should be considered as appropriate if a cardiac arrest is due to suspected digoxin toxicity (eg, digoxin fragment antibody). Other agents to consider may be bicarbonate and high dose insulin (Little, 2009).
B) CLINICAL HISTORY/EXAMINATION OBSERVABLE 1) Following resuscitation efforts (if needed), a careful review of the patient's signs and symptoms along with determining the agent and amount ingested, time since exposure, and premorbid factors are needed to assess what further treatment may be needed (Little, 2009).
2) The initial history after an ingestion is often inaccurate. In one study in children, only 57% of 75 suspected exposures could be confirmed by urine or serum drug assays (analysis was restricted to exposures where there was an assay capable of detecting the putative toxin). The physical findings of the odor of toxin on the breath (positive predictive value 100%), toxin spilled on the clothing (PPV 77%; CI 67% to 87%), or the development of signs or symptoms consistent with the putative toxin (PPV 78%; CI 68% to 88%) were much more predictive than a history of someone having seen the child ingest a substance (Hwang et al, 2003).
C) INTUBATION 1) ASSESSING NEED FOR INTUBATION a) Early intubation is likely indicated in patients that develop an alteration or reduction in consciousness to protect the airway and reduce the risk of aspiration (Boyle et al, 2009). In Australia, a study of over 4500 overdoses admissions, prolonged stays in the intensive care unit were observed in patients with aspiration (n=126 hours) as compared to patients that did not aspirate (n=14.7 hours). An increase in mortality was also observed in patients that aspirated (8.5% versus 0.4%) (Little, 2009). 1) In patients with CNS depression, ventilatory drive may also be reduced, which can result in CO2 narcosis leading to acidosis and mental status deterioration. This finding may go unrecognized if the patient is placed on high flow oxygen where the O2 saturation remains adequate despite ventilatory failure (Boyle et al, 2009).
b) SERIAL BISPECTRAL INDEX - In a prospective, observational study using a convenience sample of patients being treated for a suspected sedative ingestion who presented to an Emergency Center, a mean decrease in Serial Bispectral Index (BIS) monitoring during the initial 20 minutes following admission was able to predict the eventual need for intubation. The BIS monitor (electroencephalogram) consists of a probe that is placed on the patient's forehead and displays an analog score of 1 to 100 that represents a patient's level of awareness. A score of 100 indicates that a patient is fully awake. Patients with a score of 70 or below are rarely aware of their surroundings. Of the 11 patients that did require intubation, the mean change in BIS score over the 20-minute observation period was -13.5 (95% CI 3.2 to -30.2), and the mean change in patients who did not require intubation was +6.7 (95% CI 3.3 to 10.1). Findings suggested that a decreasing BIS score over the observation period was associated with intubation in patients with an initial BIS score above 70. Its further hypothesized that a decreasing BIS score is associated with a patient that may still be absorbing the toxin and peak intoxication has not been reached. Although an altered mental status score correlated with BIS, it was unable to detect the subtle change in mental status that were detected with BIS (Miner et al, 2006). D) MONITORING OF PATIENT 1) Initiate continuous cardiac monitoring and obtain a baseline ECG as indicated; repeat as necessary or if that patient is at risk for delayed toxicity. Drugs that may induce QT prolongation (a QTc interval greater than 440 ms in men and 460 ms in women) may lead to ventricular dysrhythmias. Other agents may inhibit fast cardiac sodium channels leading to a prolonged QRS complex. Sodium channel blocking agents comprise multiple types of drugs that can produce slowed intraventricular conduction, unidirectional block, and the development of a re-entrant circuit which can lead to ventricular tachycardia or fibrillation (Boyle et al, 2009).
E) HYPERGLYCEMIA 1) INTERFERENCE WITH BLOOD GLUCOSE MEASUREMENT: Patients receiving parenteral medications that contain maltose or galactose, or oral medications containing xylose, may have falsely elevated blood glucose levels measured using glucose dehydrogenase pyrroloquinolinequinone (GDH-PQQ) based glucose monitoring systems. Some of these patients have been treated with insulin and developed life-threatening or fatal hypoglycemia. In addition, patients with true hypoglycemia may go untreated if the hypoglycemic state is masked by false elevation of glucose readings (Anon, 2005).
F) COMA 1) Aggressively treat and evaluate coma regardless of suspected cause. Intubate and ventilate as needed. Comatose patients should receive oxygen, naloxone (Narcan(R)), thiamine (adults) and either D50 or rapid determination of glucose level. Check core temperature to evaluate for hypo- or hyperthermia. Consider evaluation for CNS lesion or infection with CT and lumbar puncture. 2) NALOXONE: The single dose method is an intravenous bolus form with the initial adult and pediatric dose of 0.4 to 2 mg (5 ampules) repeated as necessary. 3) CAUTION: The use of naloxone may induce vomiting or WITHDRAWAL SYNDROMES (Nicholson, 1983). 4) NALOXONE/SUMMARY a) Naloxone, a pure opioid antagonist, reverses coma and respiratory depression from all opioids. It has no agonist effects and can safely be employed in a mixed or unknown overdose where it can be diagnostic and therapeutic without risk to the patient.
b) Indicated in patients with mental status and respiratory depression possibly related to opioid overdose (Hoffman et al, 1991).
c) DOSE: The initial dose of naloxone should be low (0.04 to 0.4 mg) with a repeat dosing as needed or dose escalation to 2 mg as indicated due to the risk of opioid withdrawal in an opioid-tolerant individual; if delay in obtaining venous access, may administer subcutaneously, intramuscularly, intranasally, via nebulizer (in a patient with spontaneous respirations) or via an endotracheal tube (Vanden Hoek,TL,et al).
d) Recurrence of opioid toxicity has been reported to occur in approximately 1 out of 3 adult ED opioid overdose cases after a response to naloxone. Recurrences are more likely with long-acting opioids (Watson et al, 1998)
5) NALOXONE DOSE/ADULT a) INITIAL BOLUS DOSE: Because naloxone can produce opioid withdrawal in an opioid-dependent individual leading to severe agitation and hypertension, the initial dose of naloxone should be low (0.04 to 0.4 mg) with a repeat dosing as needed or dose escalation to 2 mg as indicated (Vanden Hoek,TL,et al). 1) This dose can also be given intramuscularly or subcutaneously in the absence of intravenous access (Howland & Nelson, 2011; Prod Info naloxone HCl IV, IM, subcutaneous injection solution, 2008; Maio et al, 1987; Wanger et al, 1998).
b) Larger doses may be needed to reverse opioid effects. Generally, if no response is observed after 8 to 10 milligrams has been administered, the diagnosis of opioid-induced respiratory depression should be questioned (Howland & Nelson, 2011; Prod Info naloxone HCl IV, IM, subcutaneous injection solution, 2008). Very large doses of naloxone (10 milligrams or more) may be required to reverse the effects of a buprenorphine overdose (Gal, 1989; Jasinski et al, 1978). 1) Single doses of up to 24 milligrams have been given without adverse effect (Evans et al, 1973).
c) REPEAT DOSE: The effective naloxone dose may have to be repeated every 20 to 90 minutes due to the much longer duration of action of the opioid agonist used(Howland & Nelson, 2011). 1) OPIOID DEPENDENT PATIENTS: The goal of naloxone therapy is to reverse respiratory depression without precipitating significant withdrawal. Starting doses of naloxone 0.04 mg IV, or 0.001 mg/kg, have been suggested as appropriate for opioid-dependent patients without severe respiratory depression (Howland & Nelson, 2011). If necessary the dose may be repeated or increased gradually until the desired response is achieved (adequate respirations, ability to protect airway, responds to stimulation but no evidence of withdrawal) (Howland & Nelson, 2011). In the presence of opioid dependence, withdrawal symptoms typically appear within minutes of naloxone administration and subside in about 2 hours. The severity and duration of the withdrawal syndrome are dependant upon the naloxone dose and the degree and type of dependence.(Prod Info naloxone HCl IV, IM, subcutaneous injection solution, 2008)
2) PRECAUTION should be taken in the presence of a mixed overdose of a sympathomimetic with an opioid. Administration of naloxone may provoke serious sympathomimetic toxicity by removing the protective opioid-mediated CNS depressant effects. Arrhythmogenic effects of naloxone may also be potentiated in the presence of severe hyperkalemia (McCann et al, 2002).
d) NALOXONE DOSE/CHILDREN 1) LESS THAN 5 YEARS OF AGE OR LESS THAN 20 KG: 0.1 mg/kg IV/intraosseous/IM/subcutaneously maximum dose 2 mg; may repeat dose every 2 to 5 minutes until symptoms improve (Kleinman et al, 2010; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008)
2) 5 YEARS OF AGE OR OLDER OR GREATER THAN 20 KG: 2 mg IV/intraosseous/IM/subcutaneouslymay repeat dose every 2 to 5 minutes until symptoms improve (Kleinman et al, 2010; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008; Krauss & Green, 2006). Although naloxone may be given via the endotracheal tube for pediatric resuscitation, optimal doses are unknown. Some experts have recommended using 2 to 3 times the IV dose (Kleinman et al, 2010)
3) AVOIDANCE OF OPIOID WITHDRAWAL: In cases of known or suspected chronic opioid therapy, a lower dose of 0.01 mg/kg may be considered and titrated to effect to avoid withdrawal: INITIAL DOSE: 0.01 mg/kg body weight given IV. If this does not result in clinical improvement, an additional dose of 0.1 mg/kg body weight may be given. It may be given by the IM or subQ route if the IV route is not available (Prod Info naloxone HCl IV, IM, subcutaneous injection solution, 2008)
e) NALOXONE DOSE/NEONATE 1) The American Academy of Pediatrics recommends a neonatal dose of 0.1 mg/kg IV or intratracheally from birth until age 5 years or 20 kilograms of body weight (AAP, 1989; Kleinman et al, 2010).
2) Smaller doses (10 to 30 mcg/kg IV) have been successful in the setting of exposure via maternal administration of narcotics or administration to neonates in therapeutic doses for anesthesia (Wiener et al, 1977; Welles et al, 1984; Fischer & Cook, 1974; Brice et al, 1979).
3) POTENTIAL OF WITHDRAWAL: The risk of precipitating withdrawal in an addicted neonate should be considered. Withdrawal seizures have been provoked in infants from opioid-abusing mothers when the infants were given naloxone at birth to stimulate breathing (Gibbs et al, 1989).
4) In cases of inadvertent administration of an opioid overdose to a neonate, larger doses may be required. In one case of oral morphine intoxication, 0.16 milligram/kilogram/hour was required for 5 days (Tenenbein, 1984).
f) NALOXONE/ALTERNATE ROUTES 1) If intravenous access cannot be rapidly established, naloxone can be administered via subcutaneous or intramuscular injection, intranasally, or via inhaled nebulization in patients with spontaneous respirations. 2) INTRAMUSCULAR/SUBCUTANEOUS ROUTES: If an intravenous line cannot be secured due to hypoperfusion or lack of adequate veins then naloxone can be administered by other routes. 3) The intramuscular or subcutaneous routes are effective if hypoperfusion is not present (Prod Info naloxone HCl IV, IM, subcutaneous injection solution, 2008). The delay required to establish an IV, offsets the slower rate of subcutaneous absorption (Wanger et al, 1998). 4) Naloxone Evzio(TM) is a hand-held autoinjector intended for the emergency treatment of known or suspected opioid overdose. The autoinjector is equipped with an electronic voice instruction system to assist caregivers with administration. It is available as 0.4 mg/0.4 mL solution for injection in a pre-filled auto-injector (Prod Info EVZIO(TM) injection solution, 2014). 5) INTRANASAL ROUTE: Intranasal naloxone has been shown to be effective in opioid overdose; bioavailability appears similar to the intravenous route (Kelly & Koutsogiannis, 2002). Based on several case series of patients with suspected opiate overdose, the average response time of 3.4 minutes was observed using a formulation of 1 mg/mL/nostril by a mucosal atomization device (Kerr et al, 2009; Kelly & Koutsogiannis, 2002). However, a young adult who intentionally masticated two 25 mcg fentanyl patches and developed agonal respirations (6 breaths per minute), decreased mental status and mitotic pupils did not respond to intranasal naloxone (1 mg in each nostril) administered by paramedics. After 11 minutes, paramedics placed an IV and administered 1 mg of IV naloxone; respirations normalized and mental status improved. Upon admission, 2 additional doses of naloxone 0.4 mg IV were needed. The patient was monitored overnight and discharged the following day without sequelae. Its suggested that intranasal administration can lead to unpredictable absorption (Zuckerman et al, 2014). a) Narcan(R) nasal spray is supplied as a single 4 mg dose of naloxone hydrochloride in a 0.1 mL intranasal spray (Prod Info NARCAN(R) nasal spray, 2015).
b) FDA DOSING: Initial dose: 1 spray (4 mg) intranasally into 1 nostril. Subsequent doses: Use a new Narcan(R) nasal spray and administer into alternating nostrils. May repeat dose every 2 to 3 minutes. Requirement for repeat dosing is dependent on the amount, type, and route of administration of the opioid being antagonized. Higher or repeat doses may be required for partial agonists or mixed agonist/antagonists (Prod Info NARCAN(R) nasal spray, 2015).
c) AMERICAN HEART ASSOCIATION GUIDELINE DOSING: Usual dose: 2 mg intranasally as soon as possible; may repeat after 4 minutes (Lavonas et al, 2015). Higher doses may be required with atypical opioids (VandenHoek et al, 2010).
d) ABSORPTION: Based on limited data, the absorption rate of intranasal administration is comparable to intravenous administration. The peak plasma concentration of intranasal administration is estimated to be 3 minutes which is similar to the intravenous route (Kerr et al, 2009). In rare cases, nasal absorption may be inhibited by injury, prior use of intranasal drugs, or excessive secretions (Kerr et al, 2009).
6) NEBULIZED ROUTE: DOSE: A suggested dose is 2 mg naloxone with 3 mL of normal saline for suspected opioid overdose in patients with some spontaneous respirations (Weber et al, 2012). 7) ENDOTRACHEAL ROUTE: Endotracheal administration of naloxone can be effective(Tandberg & Abercrombie, 1982), optimum dose unknown but 2 to 3 times the intravenous dose had been recommended by some (Kleinman et al, 2010). g) NALOXONE/CONTINUOUS INFUSION METHOD 1) A continuous infusion of naloxone may be employed in circumstances of opioid overdose with long acting opioids (Howland & Nelson, 2011; Redfern, 1983).
2) The patient is given an initial dose of IV naloxone to achieve reversal of opioid effects and is then started on a continuous infusion to maintain this state of antagonism.
3) DOSE: Utilize two-thirds of the initial naloxone bolus on an hourly basis (Howland & Nelson, 2011; Mofenson & Caraccio, 1987). For an adult, prepare the dose by multiplying the effective bolus dose by 6.6, and add that amount to 1000 mL and administer at an IV infusion rate of 100 mL/hour (Howland & Nelson, 2011).
4) Dose and duration of action of naloxone therapy varies based on several factors; continuous monitoring should be used to prevent withdrawal induction (Howland & Nelson, 2011).
5) Observe patients for evidence of CNS or respiratory depression for at least 2 hours after discontinuing the infusion (Howland & Nelson, 2011).
h) NALOXONE/PREGNANCY 1) In general, the smallest dose of naloxone required to reverse life threatening opioid effects should be used in pregnant women. Naloxone detoxification of opioid addicts during pregnancy may result in fetal distress, meconium staining and fetal death (Zuspan et al, 1975). When naloxone is used during pregnancy, opioid abstinence may be provoked in utero (Umans & Szeto, 1985).
G) SEIZURE 1) Numerous toxins or exposures may produce seizures. Management includes maintaining a patent airway, adequate oxygenation, treating hypoglycemia if present and avoidance of injury. First-line treatment is benzodiazepines followed by barbiturates, as necessary. Propofol may also be considered. Phenytoin should be avoided because it is usually ineffective and may worsen symptoms. Appropriate diagnostic work-up should include brain imaging if the patient does not improve with pharmacologic interventions to rule out intracranial hemorrhage or injury (Boyle et al, 2009). 2) SUMMARY a) Attempt initial control with a benzodiazepine (eg, diazepam, lorazepam). If seizures persist or recur, administer phenobarbital or propofol.
b) Monitor for respiratory depression, hypotension, and dysrhythmias. Endotracheal intubation should be performed in patients with persistent seizures.
c) Evaluate for hypoxia, electrolyte disturbances, and hypoglycemia (or, if immediate bedside glucose testing is not available, treat with intravenous dextrose).
3) DIAZEPAM a) ADULT DOSE: Initially 5 to 10 mg IV, OR 0.15 mg/kg IV up to 10 mg per dose up to a rate of 5 mg/minute; may be repeated every 5 to 20 minutes as needed (Brophy et al, 2012; Prod Info diazepam IM, IV injection, 2008; Manno, 2003).
b) PEDIATRIC DOSE: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed (Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008).
c) Monitor for hypotension, respiratory depression, and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after repeated doses of diazepam .
4) NO INTRAVENOUS ACCESS a) DIAZEPAM may be given rectally or intramuscularly (Manno, 2003). RECTAL DOSE: CHILD: Greater than 12 years: 0.2 mg/kg; 6 to 11 years: 0.3 mg/kg; 2 to 5 years: 0.5 mg/kg (Brophy et al, 2012).
b) MIDAZOLAM has been used intramuscularly and intranasally, particularly in children when intravenous access has not been established. ADULT DOSE: 0.2 mg/kg IM, up to a maximum dose of 10 mg (Brophy et al, 2012). PEDIATRIC DOSE: INTRAMUSCULAR: 0.2 mg/kg IM, up to a maximum dose of 7 mg (Chamberlain et al, 1997) OR 10 mg IM (weight greater than 40 kg); 5 mg IM (weight 13 to 40 kg); INTRANASAL: 0.2 to 0.5 mg/kg up to a maximum of 10 mg/dose (Loddenkemper & Goodkin, 2011; Brophy et al, 2012). BUCCAL midazolam, 10 mg, has been used in adolescents and older children (5-years-old or more) to control seizures when intravenous access was not established (Scott et al, 1999).
5) LORAZEPAM a) MAXIMUM RATE: The rate of intravenous administration of lorazepam should not exceed 2 mg/min (Brophy et al, 2012; Prod Info lorazepam IM, IV injection, 2008).
b) ADULT DOSE: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist (Manno, 2003; Brophy et al, 2012).
c) PEDIATRIC DOSE: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue (Brophy et al, 2012; Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008; Sreenath et al, 2010; Chin et al, 2008).
6) PHENOBARBITAL a) ADULT LOADING DOSE: 20 mg/kg IV at an infusion rate of 50 to 100 mg/minute IV. An additional 5 to 10 mg/kg dose may be given 10 minutes after loading infusion if seizures persist or recur (Brophy et al, 2012).
b) Patients receiving high doses will require endotracheal intubation and may require vasopressor support (Brophy et al, 2012).
c) PEDIATRIC LOADING DOSE: 20 mg/kg may be given as single or divided application (2 mg/kg/minute in children weighing less than 40 kg up to 100 mg/min in children weighing greater than 40 kg). A plasma concentration of about 20 mg/L will be achieved by this dose (Loddenkemper & Goodkin, 2011).
d) REPEAT PEDIATRIC DOSE: Repeat doses of 5 to 20 mg/kg may be given every 15 to 20 minutes if seizures persist, with cardiorespiratory monitoring (Loddenkemper & Goodkin, 2011).
e) MONITOR: For hypotension, respiratory depression, and the need for endotracheal intubation (Loddenkemper & Goodkin, 2011; Manno, 2003).
f) SERUM CONCENTRATION MONITORING: Monitor serum concentrations over the next 12 to 24 hours. Therapeutic serum concentrations of phenobarbital range from 10 to 40 mcg/mL, although the optimal plasma concentration for some individuals may vary outside this range (Hvidberg & Dam, 1976; Choonara & Rane, 1990; AMA Department of Drugs, 1992).
7) OTHER AGENTS a) If seizures persist after phenobarbital, propofol or pentobarbital infusion, or neuromuscular paralysis with general anesthesia (isoflurane) and continuous EEG monitoring should be considered (Manno, 2003). Other anticonvulsants can be considered (eg, valproate sodium, levetiracetam, lacosamide, topiramate) if seizures persist or recur; however, there is very little data regarding their use in toxin induced seizures, controlled trials are not available to define the optimal dosage ranges for these agents in status epilepticus (Brophy et al, 2012): 1) VALPROATE SODIUM: ADULT DOSE: An initial dose of 20 to 40 mg/kg IV, at a rate of 3 to 6 mg/kg/minute; may give an additional dose of 20 mg/kg 10 minutes after loading infusion. PEDIATRIC DOSE: 1.5 to 3 mg/kg/minute (Brophy et al, 2012).
2) LEVETIRACETAM: ADULT DOSE: 1000 to 3000 mg IV, at a rate of 2 to 5 mg/kg/min IV. PEDIATRIC DOSE: 20 to 60 mg/kg IV (Brophy et al, 2012; Loddenkemper & Goodkin, 2011).
3) LACOSAMIDE: ADULT DOSE: 200 to 400 mg IV; 200 mg IV over 15 minutes (Brophy et al, 2012). PEDIATRIC DOSE: In one study, median starting doses of 1.3 mg/kg/day and maintenance doses of 4.7 mg/kg/day were used in children 8 years and older (Loddenkemper & Goodkin, 2011).
4) TOPIRAMATE: ADULT DOSE: 200 to 400 mg nasogastric/orally OR 300 to 1600 mg/day orally divided in 2 to 4 times daily (Brophy et al, 2012).
8) RECURRING SEIZURES a) If seizures are not controlled by the above measures, patients will require endotracheal intubation, mechanical ventilation, continuous EEG monitoring, a continuous infusion of an anticonvulsant, and may require neuromuscular paralysis and vasopressor support. Consider continuous infusions of the following agents: 1) MIDAZOLAM: ADULT DOSE: An initial dose of 0.2 mg/kg slow bolus, at an infusion rate of 2 mg/minute; maintenance doses of 0.05 to 2 mg/kg/hour continuous infusion dosing, titrated to EEG (Brophy et al, 2012). PEDIATRIC DOSE: 0.1 to 0.3 mg/kg followed by a continuous infusion starting at 1 mcg/kg/minute, titrated upwards every 5 minutes as needed (Loddenkemper & Goodkin, 2011).
2) PROPOFOL: ADULT DOSE: Start at 20 mcg/kg/min with 1 to 2 mg/kg loading dose; maintenance doses of 30 to 200 mcg/kg/minute continuous infusion dosing, titrated to EEG; caution with high doses greater than 80 mcg/kg/minute in adults for extended periods of time (ie, longer than 48 hours) (Brophy et al, 2012); PEDIATRIC DOSE: IV loading dose of up to 2 mg/kg; maintenance doses of 2 to 5 mg/kg/hour may be used in older adolescents; avoid doses of 5 mg/kg/hour over prolonged periods because of propofol infusion syndrome (Loddenkemper & Goodkin, 2011); caution with high doses greater than 65 mcg/kg/min in children for extended periods of time; contraindicated in small children (Brophy et al, 2012).
3) PENTOBARBITAL: ADULT DOSE: A loading dose of 5 to 15 mg/kg at an infusion rate of 50 mg/minute or lower; may administer additional 5 to 10 mg/kg. Maintenance dose of 0.5 to 5 mg/kg/hour continuous infusion dosing, titrated to EEG (Brophy et al, 2012). PEDIATRIC DOSE: A loading dose of 3 to 15 mg/kg followed by a maintenance dose of 1 to 5 mg/kg/hour (Loddenkemper & Goodkin, 2011).
4) THIOPENTAL: ADULT DOSE: 2 to 7 mg/kg, at an infusion rate of 50 mg/minute or lower. Maintenance dose of 0.5 to 5 mg/kg/hour continuous infusing dosing, titrated to EEG (Brophy et al, 2012)
b) Endotracheal intubation, mechanical ventilation, and vasopressors will be required (Brophy et al, 2012) and consultation with a neurologist is strongly advised. c) Neuromuscular paralysis (eg, rocuronium bromide, a short-acting nondepolarizing agent) may be required to avoid hyperthermia, severe acidosis, and rhabdomyolysis. If rhabdomyolysis is possible, avoid succinylcholine chloride, because of the risk of hyperkalemic-induced cardiac dysrhythmias. Continuous EEG monitoring is mandatory if neuromuscular paralysis is used (Manno, 2003). |