Acetaminophen

Due to lack of early clinical signs of toxicity, perform a Tylenol level on all patients with intentional drug OD.

7.5 g or >140 mg/kg

Toxic blood levels = 15 µg/dl

Rumacks Matthews nomogram—plotting acetaminophen levels vs. the time since ingestion can predict probable hepatotoxicity. Limited use in cases of chronic toxicity, time since ingestion unknown, and sustained release preparations.

7-24 h: Anorexia, nausea and vomiting, and diaphoresis. 24-48 h: Hepatic toxicity Pain in right upper quadrant with elevated liver enzymes (AST first)

72-96 h: Peak levels of hepatic enzymes and hepatic failure.

Resolution phase: Symptoms abate in ~4 d; 1-3 weeks for hepatic regeneration.

Obtain baseline levels and monitor liver enzymes for at least 3 d.

Activated charcoal ASAP after ingestion.

N-acetyl cysteine (Mucomyst) 140 mg /kg p.o. as loading dose and then 70 mg/kg every 4 h until 17 doses, while continuously monitoring acetaminophen levels. Optimal use within the first 8 h.

Hepatology consultation-for further management and in the event of hepatic failure to evaluate for possible liver transplant.

Aspirin (acetylsalicylic acid)

Toxic → 150-300 mg/kg

Lethal → 500 mg/kg

Chronic ingestion = 100 mg/kg/d over several days. Toxic blood levels = 39 µg/ml

Blood levels should be drawn in 6 h or more to predict further course.

Draw a level 2 h until decline.

Limited use in cases of chronic toxicity and sustained release preparations due to erratic and slowed absorption.

Initial symptoms include nausea, vomiting, tinnitus, hyperventilation, and altered level of consciousness.

Later symptoms suggestive of a poor prognosis include lethargy, pulmonary edema, convulsions, and coma.

Stat labs for complete blood cell count (CBC), CHEM 7, arterial blood gases (ABG), and PT/PTT.

Maintain continuous cardiac monitoring and pulse oximetry.

Gastrointestinal (GI) decontamination with activated charcoal/gastric lavage (within 1 h).

Careful rehydration/correction of K depletion.

Alkalinize urine, monitor serum pH to prevent systemic alkalosis.

Do not attempt forced diuresis.

Toxic levels or any acid-base imbalance warrants an admission to an ICU and nephrology consultation.

Amphetamines

20-25 mg/kg

Mydriasis, agitation, irritability, psychotic symptoms, fever, flushing, nausea, vomiting, and diarrhea.

Severe cases-rhabdomyolysis, renal failure, intracranial bleed, myocardial infarction (MI), arrthymias, aortic dissections, seizures, coma.

Monitor CHEM 7, creatine phosphokinase (CPK), EKG.

Administration of activated charcoal/gastric lavage (for large doses).

Management of agitation with benzodiazepines, avoiding neuroleptics as much as possible.

Avoid restraints to prevent rhabdomyolysis.

Adequate hydration to prevent acute renal failure secondary to rhabdomyolysis.

Treat hyperthermia, hypertension, and arrthymias.

Benzodiazepines

Drowsiness, ataxia, slurred speech, respiratory depression, coma.

Airway, breathing, and circulation.

Gastric lavage/activated charcoal.

Flumazenil (do not use in patients who are predisposed to or have a history of a seizure disorder)—fast action.

Treat hypotension and bradycardia.

Cocaine

Initial hyperadrenergic state, with mydriasis, hypertension, tachycardia and hyperventilation, muscular twitching, agitation, altered state of consciousness.

Sympathetic overload transitions into central nervous system (CNS) and cardiopulmonary depression, with complications encompassing seizures, stroke, subarachnoid hemorrhage, MI, arrhythmias, and pulmonary edema.

Baseline labs and continuous monitoring of CBC, CHEM 7, ABG, CPK, EKG.

Monitor and maintain airway, breathing, and circulation.

Management of agitation with benzodiazepines, avoiding neuroleptics as much as possible.

Avoid restraints to prevent rhabdomyolysis. Treat rhabdomyolysis, seizures, hyperthermia, hypertension, arrhythmias, and other cardiac complications.

Phenothiazines (haloperidol, chlorpromazine, thioridazine)

150 mg/kg

Anticholinergic effects, extrapyramidal effects, cardiac complications, seizures, coma.

Airway, breathing, and circulation.

Monitor CHEM 7, CPK.

Continuous cardiac monitoring.

Activated charcoal/gastric lavage.

Emesis contraindicated.

Treatment of arrhythmias, hypotension, hyperthermia, and seizures.

Atypical antipsychotics (clozapine, olanzapine, risperidone, quetiapine, and ziprasidone)

Anticholinergic effects, CNS depression, cardiac abnormalities (hypotension, tachycardia, QT and QTc prolongation, particularly with ziprasidone).

Agranulocytosis with clozapine.

Airway, breathing, and circulation.

Monitor CHEM 7, CPK liver function tests (LFTs).

Continous cardiac monitoring.

EKG/telemetry.

Activated charcoal/gastric lavage.

Tricyclic antidepressants (amitriptyline, nortriptyline, desipramine)

30-50 mg/kg lethal dose.

Erratic course, and patients may decompensate rapidly.

Earliest signs—altered mental status, slurred speech, tachycardia, hypoventilation, and anticholinergic symptoms.

Cardiovascular manifestations— increased QT interval, conduction defects, arrhythmias, and systemic hypotension.

CNS manifestations—agitation, myoclonic jerks, seizures, and coma.

Treat hypotension, arrhythmias, and seizures.

Monitor electrolytes and ABG.

Serum tricyclic antidepressant levels correlate poorly with severity of toxicity.

IV access, O2 and continuous cardiac monitoring, alkalinization.

Gastric lavage/multiple dose activated charcoal.

Treat hypotension, arrhythmias, and seizures.

Lithium

Single ingestions of 20 mg/kg → toxic

Peak levels of LiCO₃ in 2-4 h post ingestion.

Slow release formulations peak 6 h after ingestion.

Toxicity may be secondary to dehydration, decreased dietary sodium, and addition of thiazide diuretics, NSAIDS.

Mild intoxication → (1.5-2.0 mEq/L) GI → Vomiting, nausea, abdominal pain, thirst. Neurological → Tremor, ataxia, dizziness, slurred speech, nystagmus, lethargy, and muscle weakness. Moderate intoxication (2.0-2.5 mEq/L)

GI → persistent nausea and vomiting.

Neurological → blurred vision, muscle fasciculations, myoclonus, hyperactive deep tendon reflexes, choreoathetoid movements, convulsions, delirium, coma, hemodynamic failure.

Severe intoxication → Lithium level >2.5 mEq/L Seizures, cardiac arrhythmias, coarse tremors, hypotension, renal failure, and death.

Check Li levels, CHEM 7, renal function, EKG and continuous cardiac monitoring.

Gastric lavage (if ingestion less then 1 h ago), emesis, sodium polystyrene sulfonate.

Polyethylene glycol in the presence of rising lithium levels refractory to above treatment.

Vigorous hydration and maintenance of electrolyte balance is essential.

Hemodialysis indicated for Li level >4.0 mEq/L, renal failure, altered mental status, seizures, arrhythmias, and pulmonary edema.

Continue checking lithium levels until two consecutive levels show a downward trend.

Phencyclidine

Agitation, hallucinations, hypertension, hyperpyrexia, tachycardia, vertical nystagmus, rhabdomyolysis, decreased sensitivity to pain.

Stupor, coma, analgesia, seizures, respiratory depression, renal failure secondary to rhabdomyolysis.

Monitor electrolytes, CPK and BUN/Cr.

Supportive treatment.

Management of agitation with benzodiazepines, avoiding neuroleptics as much as possible.

Minimize stimulation and caution due to increased risk of violence.

Restraints should be avoided due to risk of rhabdomyolysis.

Decontamination measures such as gastric lavage may be countertherapeutic by way of increasing agitation.

Selective serotonin reuptake inhibitors (fluoxetine, sertraline, paroxetine, citalopram)

Altered mental status, confusion, vertigo, ataxia, psychosis, GI symptoms (nausea and vomiting), tachycardia, rare arrhythmias and seizures.

Monitor EKG (especially with citalopram) and for any symptoms that are suggestive of serotonin syndrome.

Gastric lavage/activated charcoal.

Treat arrhythmias, seizures.

Valproate

Somnolence, confusion, GI upset progressing to respiratory depression, arrhythmias, pancreatitis, and drug-induced hepatitis and coma.

Check CHEM 7, LFTs, amylase, lipase, CBC with differential.

Continuous cardiac monitoring.

Supportive management including respiratory support, gastric lavage.

Treat seizures.

This table presents characteristic features of drug overdose and general principles of acute management. Please refer to a detailed clinical reference for comprehensive management.