You are in: eMedicine Specialties > Pediatrics: General Medicine > Pulmonology Hydrocarbon Inhalation InjuryArticle Last Updated: Jun 25, 2008AUTHOR AND EDITOR INFORMATIONAuthor: Jason M Kane, MD, FAAP, Assistant Professor of Pediatrics, Northwestern University Feinberg School of Medicine; Attending Physician, Department of Pediatrics, Section of Pediatric Critical Care and Cardiac Intensive Care, Children's Memorial Hospital Jason M Kane is a member of the following medical societies: American Academy of Pediatrics, American College of Chest Physicians, American Thoracic Society, and Society of Critical Care Medicine Coauthor(s): Emily B Nazarian, MD, Fellow, Department of Pediatrics, Division of Critical Care, University of Rochester Medical Center; Heidi Connolly, MD, Associate Professor of Pediatrics and Psychiatry, University of Rochester; Director, Pediatric Sleep Medicine Services, Strong Sleep Disorders Center Editors: Girish D Sharma, MD, Associate Professor, Department of Pediatrics, Rush University Medical Center, Rush Children's Hospital; Director of Pediatric Pulmonary Section and Rush Cystic Fibrosis Center; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Charles Callahan, DO, Professor, Deputy Chief of Clinical Services, Walter Reed Army Medical Center; Mary E Cataletto, MD, Associate Director, Division of Pediatric Pulmonology, Winthrop University Hospital; Associate Professor, Department of Clinical Pediatrics, State University of New York at Stony Brook; Michael R Bye, MD, Attending Physician, Pediatric Pulmonary Medicine, Columbia University Medical Center; Professor of Clinical Pediatrics, Division of Pulmonary Medicine, Columbia University College of Physicians and Surgeons Author and Editor Disclosure Synonyms and related keywords: hydrocarbon inhalation injury, volatile substance abuse, inhalant abuse, solvent abuse, sniffing, huffing, bagging, solvent, butane, toluene, sudden cardiac events, sudden sniffing death syndrome, ventricular dysrhythmias, sudden death, myocardial infarction, renal tubular acidosis, hypokalemia, hyperchloremia, frostbite, bone marrow damage, aplastic anemia, leukemia, toxic hepatitis, pulmonary injury, microcephaly, narrow bifrontal diameter, short palpebral fissures, hypoplastic mid face, wide nasal bridge, abnormal palmar creases, blunt fingertips, pulmonary hypertension, hydrocarbon aspiration, Parkinson disease, attention deficit, rhabdomyolysis, rhinitis, nasal mucosal erosions, epistaxis, hoarse voice, conjunctivitis, hypophosphatemia, hypercalcemia INTRODUCTIONBackgroundInhalation injury due to hydrocarbons can occur as a result of either accidental or intentional exposure. Inhalant abuse, the deliberate inhalation of hydrocarbons as a form of recreational drug use, has become a significant health issue affecting children. Epidemiologic data state that, among adolescents, inhalants are the second most widely used class of illicit drugs; more than 2 million children aged 12-17 years report using inhalants at least once in their lifetime. Death from intentional inhalation of hydrocarbon fumes is not uncommon and is usually due to sudden cardiac events or CNS depression. The recognition and treatment of inhalant abuse remain challenges for pediatricians and emergency physicians. Deliberate inhalation of volatile hydrocarbons for their mood-altering effects is popular among adolescents. Their low cost, ready availability, and ease of use contribute to this problem. Volatile hydrocarbons are contained in glues, solvents, lighter fluid, gasoline, and paints. Most inhalants are composed of several compounds, and almost all pressurized aerosol products can be abused because the propellants are volatile hydrocarbons. Inhalation is most commonly achieved by sniffing, huffing, or bagging.1 PathophysiologyThe exact mechanism of action for the volatile substances on the whole is unknown. Two theories have been postulated for the mechanism of action of inhalants. One hypothesis is that the volatile solvents produce a generalized slowing of axonal ion-channel transport by altering the membranes, similar to anesthetic gasses.2 The second theory suggests that potentiation of the GABA receptors occurs; a cross-tolerance between 1,1,1-trichloroethane, toluene, ethanol, barbiturates, and benzodiazepines is noted.3
Chronic abusers generally inhale 3-4 times daily for 10-15 minutes each time, although prolonged sessions of inhaling 6-7 hours a day as a group activity have been described. Tolerance and physical dependence can occur, although withdrawal symptoms are only infrequently reported. Two primary organ systems are affected by inhalation hydrocarbon toxicity: the CNS and the cardiopulmonary system. Volatile hydrocarbons are highly lipid soluble and readily cross the blood-brain barrier. Rapid absorption occurs across the large surface area of the pulmonary vascular bed, and peak blood levels are noted approximately 15-30 minutes after inhalation. Confusion, disorientation, disinhibition, and euphoria are exhibited early. Speech becomes slurred, and motor function becomes impaired, with gait becoming staggered. Hallucinations are frequently described, followed by CNS depression, drowsiness, and sleep. Coma can occur with prolonged or repeated exposures; however, this is unusual because the intentional exposure ceases as the user becomes drowsy. Sudden sniffing death syndrome was first described by Bass in 1970.4 Death occurs after the user is startled during or soon after inhalation. Hydrocarbons can sensitize the myocardium to endogenous and exogenous catecholamines, which can precipitate ventricular dysrhythmias and sudden death.5, 6 In addition, some limited data have shown toxic effects of hydrocarbons directly on the myocardium, and excess catecholamine concentrations may cause an increase in oxygen demand, coronary artery spasm, platelet aggregation, and thrombus formation.7 Numerous case reports also detail acute myocardial infarction as a complication following hydrocarbon inhalation.8, 9, 10 With acute intoxication, deaths due to asphyxiation from a plastic bag over the head or from aspiration of stomach contents are not unusual. Also, trauma-related injury and motor vehicle accidents have been reported, resulting from disinhibition and disorientation following inhalation. Many solvents, particularly toluene, are lipophilic and readily cross the placenta, resulting in characteristic fetal anomalies that include microcephaly, narrow bifrontal diameter, short palpebral fissures, hypoplastic mid face, wide nasal bridge, abnormal palmar creases, and blunt fingertips. The syndrome of toluene embryopathy closely resembles the phenotypic features found in fetal alcohol syndrome.15, 16 With long-term hydrocarbon inhalation, CNS damage occurs, including loss of cognitive functions, gait disturbances, and loss of coordination. Radiographic tests have demonstrated loss of brain mass and white-matter degeneration. Additionally, certain chemicals have been shown to have associations with specific CNS injuries, including peripheral neuropathy, deafness, and optic neuropathy. Other, less common complications of long-term hydrocarbon inhalation include restrictive pulmonary disease, pulmonary hypertension, and reduced diffusion capacity.17, 18, 19 Pulmonary toxicity can occur as a result of hydrocarbon aspiration. This injury differs from hydrocarbon inhalation injury. The most common clinical scenario of hydrocarbon aspiration is a young child unintentionally ingesting a hydrocarbon-containing compound such as lamp oil or a cleaning solvent. Hydrocarbons cause direct injury to the respiratory epithelium, producing inflammation and bronchospasm. Direct contact with alveolar membranes can lead to hemorrhage, hyperemia, edema, surfactant inactivation, leukocyte infiltration, and vascular thrombosis. The result is poor oxygen exchange, atelectasis, and pneumonitis. For more information, see Toxicity, Hydrocarbons. FrequencyUnited StatesNational surveys of adolescents in the United States have revealed that, after marijuana, inhalants are the most commonly used class of illicit drugs for 8th and 10th graders; inhalants are the third most widely used illicit drugs for 12th graders.20 The low cost, ease of use, and ready availability of organic solvents perpetuate their abuse. Epidemiologic data suggest a decrease in the prevalence of inhalant abuse, but overall abuse rates remain high. Although the trend of lifetime use decreases between the 8th and 12th grades, these data may underestimate the true lifetime use of older adolescents because many students have dropped out of school by the 12th grade and, thus, are no longer included in the survey. The typical person who abuses inhalants is a young male of lower socioeconomic class. Overall, males are twice as likely to abuse inhalants as females; however, between the 8th and 12th grades, the difference is less pronounced. Immigrants from Latin America and American Indians have a higher prevalence of use, and blacks have a low prevalence of inhalant abuse. Although inhalant abuse is typically thought of as being most common among adolescents, abuse among adults is also well described, and abuse in children as young as age 4-6 years has been reported.23, 24, 22 InternationalThe United Kingdom is the only major country in the Western world that tracks inhalant abuse fatalities; an incidence of 2 deaths per week has been documented. In Canada, the patterns of inhalant use are similar to those associated with other illicit substances for experimenters, intermittent users, and long-term abusers. Long-term use tends to be endemic in both the inner-city areas and remote communities, and data show an association between chronic use, lower socioeconomic class, and family dysfunction. Mortality/MorbidityAlthough hydrocarbon inhalation was previously thought to be a benign fad, permanent and significant pulmonary and neurologic sequelae clearly may persist even after abuse has discontinued. Recreational solvent inhalation may account for as much as 2% of all deaths among adolescent males. In the United Kingdom, 15% of deaths caused by inhalants occur as a result of suffocation, 15% are a result of accidental trauma, and 15% are a result of aspiration, whereas the remaining 55% are a result of sudden sniffing death syndrome.25, 26 The fact that 22% of victims of sudden sniffing death syndrome had no history of inhalant abuse is of significant concern, demonstrating that death can result from any episode of inhalant abuse. In the United States, inhalant abuse was responsible for 12.2% of the deaths reported to poison control centers in the group aged 13-19 years. Given that many inhalant-related deaths are never reported to poison control centers, this statistic grossly underestimates the true mortality due to inhalant abuse.22 As solvent abuse becomes chronic, damage to the CNS becomes irreversible, with changes occurring in the cerebellar and cerebral white matter, including demyelination and gliosis. Psychiatric disorders, spasticity, cognitive changes, and secondary Parkinson disease have been reported. Attention deficit and decreased memory retrieval may also occur.28 RacePrevious data suggested the highest inhalant abuse to be among Latin American immigrants. In adolescents aged 12-17 years, inhalant users were more likely to be American Indian or Alaskan Native (13.2%), followed by multiracial (11.2%) and white (9.5%).29, 22 Lowest reported rates were among blacks (5.3%) and Asians (6.5%). SexAccording to data from Wu et al in 2004, the lifetime prevalence rates of inhalant abuse were not significantly different for males and females aged 12-17 years.22 AgePeak age of inhalant abuse is 14-15 years, with onset of abuse occurring from ages 6-8 years. Use typically declines by the late teenage years; however, some users continue to abuse inhalants into adulthood. CLINICALHistoryA high index of suspicion is required because exposure to most volatile substances is not detectible by physical examination and because people who intentionally abuse inhalants initially deny hydrocarbon inhalation. Presentation of a patient with a characteristic odor of gasoline or kerosene likely suggests exposure; however, patients who present with altered mental status or intoxication should be scrutinized for the possibility of inhalation abuse in addition to abuse of other common drugs. Populations at higher risk should be questioned more carefully; high-risk populations include children and adolescents from families of low socioeconomic status, in whom unemployment and poverty rates are high, as well as those lacking adult supervision.
PhysicalPatients who have acute decompensation from solvent-inhalant abuse are frequently found near the offending agent; however, many patients who present to medical care have no obvious physical findings to suggest hydrocarbon exposure or inhalant abuse. Some patients may present with subtle signs of abuse, such as paint staining around the mouth or nose. A characteristic odor may be detectable on presentation because a significant proportion of the absorbed chemical exits the body via the lungs. Also, the product may have been spilled onto clothing during use. Evidence of chronic inhalant abuse may be more subtle. Patients presenting with unexplained peripheral neuropathy and weakness, diffuse GI symptoms, or neuropsychiatric symptoms should raise suspicion of chronic solvent-inhalant abuse. Electrolyte abnormalities, including hypokalemia, hypophosphatemia, and acidosis, should further raise suspicion. However, the nature of these symptoms is not diagnostic of solvent-inhalant abuse; therefore, a very broad differential diagnosis is required. Signs and symptoms are as follows:
CausesThe common idea that solvent inhalation is innocuous undoubtedly contributes to solvent-inhalant abuse. The wide availability of organic solvents in commonly used household products makes them readily accessible.
DIFFERENTIALSAcidosis, Metabolic Inhalation Injury Status Epilepticus Toxicity, Carbon Monoxide Toxicity, Ethanol Toxicity, Tricyclic Antidepressant Ventricular Fibrillation
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| Drug Name | Potassium phosphate (Neutra-Phos-K, K-Phos) |
|---|---|
| Description | Preferable to potassium chloride because it allows for correction of both hypokalemia and hypophosphatemia. Contains 4.4 mEq of potassium per 3 mmol of phosphate. Elemental phosphorus equals 31.25 mg/mmol. Should be ordered in millimols of phosphorus, not milliequivalents of potassium, to avoid confusion as to the phosphorus content. |
| Adult Dose | 3-4.5 g (95-142.4 mmol) per d PO divided tid/qid Alternatively, 1.5-2 g (47.5-63.3 mmol) IV over 24 h |
| Pediatric Dose | 0.08-0.24 mmol/kg IV infused over 4-6 h; reassess phosphorus level before additional doses |
| Contraindications | Hyperkalemia; renal failure; conditions in which potassium retention is present; oliguria or azotemia; crush syndrome; severe hemolytic reactions; anuria; adrenocortical insufficiency |
| Interactions | Concurrent use with ACE inhibitors may result in elevated serum potassium concentrations; potassium-sparing diuretics and potassium-containing salt substitutes can produce severe hyperkalemia; in patients taking digoxin, hypokalemia may result in digoxin toxicity; caution if discontinuing potassium administration in patients maintained on digoxin |
| Pregnancy | A - Fetal risk not revealed in controlled studies in humans |
| Precautions | Do not rapidly infuse because rapid or central IV infusion may cause cardiac arrhythmias; high plasma concentrations of potassium may cause death because of cardiac depression, arrhythmias, or arrest; plasma levels do not necessarily reflect tissue levels; patients receiving infusions >0.5 mEq (potassium) per kg/h (>20 mEq/h) should be on an ECG monitor; when a concentration >40 mEq (potassium) per L is infused, local pain and phlebitis may also follow; do not co-infuse with calcium-containing products |
| Drug Name | Calcium gluconate |
|---|---|
| Description | Patients with hypocalcemia may need replacement, particularly in the presence of carpopedal spasm or hypocalcemic seizures. One gram of calcium gluconate equals 90 mg of elemental calcium. |
| Adult Dose | 5-15 g/d PO/IV divided q6h |
| Pediatric Dose | Infants: 400-800 mg/kg/d PO divided q6h; alternatively, 200-500 mg/kg/24 h IV divided q6h Children: 200-500 mg/kg/d PO/IV divided q6h |
| Contraindications | Renal calculi; hypercalcemia; hypophosphatemia; renal or cardiac disease; digitalis toxicity; IV push |
| Interactions | May decrease effects of tetracyclines, atenolol, salicylates, iron salts, and fluoroquinolones; antagonizes effects of verapamil; large intakes of dietary fiber may decrease calcium absorption and levels |
| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus |
| Precautions | Do not exceed 100 mg/min IV if undiluted; for diluted IV infusion, do not exceed 120-240 mg/kg/h, with a maximum concentration of 50 mg/mL; do not administer IM or SC; avoid scalp veins; watch peripheral infusion because extravasation may cause tissue necrosis; IV infusion may be associated with hypotension and bradycardia; in digitalized patients, may be associated with arrhythmias |
These agents are used for withdrawal symptoms or seizure activity in inhalation cases.
| Drug Name | Phenobarbital (Luminal, Solfoton) |
|---|---|
| Description | Most helpful if withdrawal symptoms are evident. Can be continued for sedation for 5-10 d. Therapeutic level is 15-40 mg/L. |
| Adult Dose | Seizures: Loading dose: 15-20 mg/kg IV, start with 10 mg/kg and follow with the subsequent 10 mg/kg if needed; not to exceed 20 mg/kg Maintenance dose: 60-200 mg/d PO/IV divided bid/tid Sedation: 30-120 mg/d PO/IV divided bid/tid |
| Pediatric Dose | Seizures: Loading dose for neonates, infants, or children: 5-20 mg/kg/dose IV in a single or divided dose; may administer an additional 5 mg/kg/dose q15-30 min; not to exceed a cumulative dose of 30 mg/kg for seizure activity Maintenance dose (monitor levels): Neonates: 3-5 mg/kg/d PO/IV qd or divided bid Infants: 5-6 mg/kg/d PO/IV qd or divided bid Children 1-5 years: 6-8 mg/kg/d PO/IV qd or divided bid Children 6-12 years: 4-6 mg/kg/d PO/IV qd or divided bid >12 years: 1-3 mg/kg/d PO/IV qd or divided bid Sedation of children: 6 mg/kg/d PO divided tid |
| Contraindications | Documented hypersensitivity; severe respiratory disease; marked impairment of liver function; nephritis; porphyria |
| Interactions | CYP450 inducer; may decrease effects of chloramphenicol, digitoxin, corticosteroids, carbamazepine, theophylline, verapamil, metronidazole, and anticoagulants (patients stabilized on anticoagulants may require dosage adjustments if added to or withdrawn from their regimen); coadministration with alcohol may produce additive CNS effects and death; chloramphenicol, valproic acid, and MAOIs may increase phenobarbital toxicity; rifampin may decrease phenobarbital effects; induction of microsomal enzymes may result in decreased effects of PO contraceptives in women (must use additional contraceptive methods to prevent unwanted pregnancy; menstrual irregularities may also occur) |
| Pregnancy | D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus |
| Precautions | IV push not to exceed 1 mg/kg/min or 100 mg/min; IV administration may cause respiratory arrest and hypotension or paradoxical reactions in children (eg, hyperactivity, irritability, insomnia); caution in hepatic or renal disease; adverse effects include drowsiness, cognitive impairment, ataxia, hypotension, hepatitis, rash, respiratory depression, apnea, megaloblastic anemia, and anticonvulsant hypersensitivity syndrome |
| Drug Name | Diazepam (Valium) |
|---|---|
| Description | Used for sedation if withdrawal symptoms present. Depresses all levels of CNS (eg, limbic and reticular formation), possibly by increasing activity of GABA. Individualize dosage and increase cautiously to avoid adverse effects. |
| Adult Dose | 2-10 mg/dose PO q6-12h prn 2-10 mg/dose IV/IM prn; not to exceed 30 mg/8 h |
| Pediatric Dose | 0.12-0.8 mg/kg/d PO divided q6-8h 0.04-0.2 mg/kg/dose IV/IM q2-4h prn; not to exceed 0.6 mg/kg within an 8-h period |
| Contraindications | Documented hypersensitivity; narrow-angle glaucoma |
| Interactions | CNS toxicity increased with coadministration of other CNS depressants (eg, phenothiazines, barbiturates, alcohol, MAOIs) |
| Pregnancy | D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus |
| Precautions | Hypotension and respiratory depression may occur; use with caution in glaucoma, shock, and depression; administer the conventional IV product undiluted no faster than 2 mg/min; do not mix with IV fluids |
| Drug Name | Phenytoin (Dilantin) |
|---|---|
| Description | May act in motor cortex where may inhibit spread of seizure activity. Activity of brainstem centers responsible for tonic phase of grand mal seizures may also be inhibited. Dose should be individualized. Administer larger dose before retiring if dose cannot be divided equally. Therapeutic level is 10-20 mg/L. |
| Adult Dose | 100 mg/dose PO/IV q8h initially and carefully titrate to 300-600 mg/d (or 6-7 mg/kg/d) divided q8-24h |
| Pediatric Dose | Loading dose: 15-20 mg/kg IV; not to exceed 1500 mg/d Maintenance dose: 5 mg/kg/d PO/IV divided q8-12h initially Divide daily doses bid/tid unless extended cap Typical dosage ranges: Neonates: 5-8 mg/kg/d 6 months to 3 years: 8-10 mg/kg/d 4-6 years: 7.5-9 mg/kg/d 7-9 years: 7-8 mg/kg/d 10-16 years: 6-7 mg/kg/d |
| Contraindications | Documented hypersensitivity; sinoatrial block; second- and third-degree AV block; sinus bradycardia; Adams-Stokes syndrome |
| Interactions | Amiodarone, benzodiazepines, chloramphenicol, cimetidine, fluconazole, isoniazid, metronidazole, miconazole, phenylbutazone, succinimides, sulfonamides, omeprazole, phenacemide, disulfiram, ethanol (acute ingestion), trimethoprim, and valproic acid may increase phenytoin toxicity; CYP450 inducer; phenytoin effects may decrease when taken concurrently with barbiturates, diazoxide, ethanol (chronic ingestion), rifampin, antacids, charcoal, carbamazepine, theophylline, and sucralfate; phenytoin may decrease effects of acetaminophen, corticosteroids, dicumarol, disopyramide, doxycycline, estrogens, haloperidol, amiodarone, carbamazepine, cardiac glycosides, quinidine, theophylline, methadone, metyrapone, mexiletine, PO contraceptives, and valproic acid |
| Pregnancy | D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus |
| Precautions | Perform CBC counts and urinalyses when therapy is begun and at monthly intervals for several months thereafter to monitor for blood dyscrasias; discontinue use if a rash appears and do not resume use if rash is exfoliative, bullous, or purpuric; rapid IV infusion may result in death from cardiac arrest, marked by QRS widening; caution in acute intermittent porphyria and diabetes (may elevate blood sugars); discontinue use if hepatic dysfunction occurs |
| Drug Name | Lorazepam (Ativan) |
|---|---|
| Description | Sedative hypnotic with short onset of effects and relatively long half-life. By increasing the action of GABA, which is a major inhibitory neurotransmitter in the brain, may depress all levels of CNS, including limbic and reticular formation. Important to monitor patient's blood pressure after administering dose. Adjust as necessary. |
| Adult Dose | 4 mg/dose IV slowly over 2-5 min and repeat in 10-15 min prn; cumulative dose of 8 mg/d typically considered maximum 1-10 mg/d PO/IV/IM divided bid/tid |
| Pediatric Dose | Infants and children: 0.1 mg/kg IV slowly over 2-5 min; may repeat with dose of 0.05 mg/kg in 10-15 min if needed; not to exceed 4 mg/dose Adolescents: 0.07 mg/kg IV slowly over 2-5 min and repeat in 10-15 min prn; not to exceed 4 mg/dose |
| Contraindications | Documented hypersensitivity; preexisting CNS depression, hypotension, and narrow-angle glaucoma; reversal agents (eg, flumazenil) contraindicated when lorazepam used for life-threatening conditions (eg, control of intracranial pressure or status epilepticus) |
| Interactions | Toxicity of benzodiazepines in CNS increases when used concurrently with alcohol, phenothiazines, barbiturates, and MAOIs |
| Pregnancy | D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus |
| Precautions | Caution in renal or hepatic impairment, myasthenia gravis, organic brain syndrome, or Parkinson disease |
These agents may be required to treat tachycardias.
| Drug Name | Amiodarone (Cordarone) |
|---|---|
| Description | Class III antiarrhythmic. Has antiarrhythmic effects that overlap all 4 Vaughn-Williams antiarrhythmic classes. May inhibit AV conduction and sinus node function. Prolongs action potential and refractory period in myocardium and inhibits adrenergic stimulation. Only agent proven to reduce incidence and risk of cardiac sudden death, with or without obstruction to LV outflow. Very efficacious in converting atrial fibrillation and flutter to sinus rhythm and in suppressing recurrence of these arrhythmias. Has low risk of proarrhythmia effects, and any proarrhythmic reactions are generally delayed. Used in patients with structural heart disease. Most clinicians are comfortable with inpatient or outpatient loading with 400 mg PO tid for 1 wk because of low proarrhythmic effect, followed by weekly reductions with goal of lowest dose with desired therapeutic benefit (usual maintenance dose for AF 200 mg/d). During loading, patients must be monitored for bradyarrhythmias. Before administration, control the ventricular rate and CHF (if present) with digoxin or calcium channel blockers. PO efficacy may take weeks. With exception of disorders of prolonged repolarization (eg, LQTS), may be DOC for life-threatening ventricular arrhythmias refractory to beta blockade and initial therapy with other agents. |
| Adult Dose | Loading dose: 800-1600 mg/d PO in 1-2 doses for 1-3 wk, and decrease to 600-800 mg/d in 1-2 doses for 1 mo Maintenance dose: 400 mg/d PO Alternatively, 150 mg (10 mL) IV over first 10 min, followed by 360 mg (200 mL) over next 6 h and, then, 540 mg over next 18 h |
| Pediatric Dose | 10-15 mg/kg/d or 600-800 mg/1.73 m2/d PO for 4-14 d or until arrhythmia controlled |
| Contraindications | Documented hypersensitivity, complete AV block, and intraventricular conduction defects |
| Interactions | Increases effect and blood levels of theophylline, quinidine, procainamide, phenytoin, methotrexate, flecainide, digoxin, cyclosporine, beta blockers, and anticoagulants; cardiotoxicity of amiodarone is increased by macrolide antibiotics, ritonavir, sparfloxacin, and disopyramide; coadministration with calcium channel blockers, may cause an additive effect and decrease myocardial contractility further; cimetidine may increase amiodarone levels; protease inhibitors (eg, indinavir, ritonavir, amprenavir, nelfinavir) inhibit amiodarone metabolism resulting in increased serum levels and may prolong QT interval; coadministration may increase myopathy/rhabdomyolysis risk; associated with HMG-CoA reductase inhibitors (eg, simvastatin); other drugs that prolong the QT interval (eg, fluoroquinolones, erythromycin, dofetilide, tricyclic antidepressants, thioridazine) may increase life-threatening arrhythmia risk |
| Pregnancy | D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus |
| Precautions | Known to cause serious (and at times fatal) toxicities, including pulmonary and liver toxicities; may cause prolonged proarrhythmic effects; may cause optic neuritis/neuropathy or hypothyroidism or hyperthyroidism; CNS and GI toxicity may occur and typically dissipates with dose reduction |
National Institute on Drug Abuse. NIDA Research Report - Inhalant Abuse. National Institutes of Health. Available at http://www.nida.nih.gov/researchreports/inhalants/Inhalants.html.
Hydrocarbon Inhalation Injury excerpt
Article Last Updated: Jun 25, 2008