Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 38-57: Theophylline & Caffeine Overdose + Key Features Download Section PDF Listen +++ ++ Methylxanthines including theophylline and caffeine are nonselective adenosine receptor antagonists In overdose, toxicity results from the release of endogenous catecholamines with beta-1- and beta-2-adrenergic stimulation Theophylline May cause intoxication after an acute single overdose or Intoxication may occur as a result of chronic accidental repeated overmedication or reduced elimination resulting from liver dysfunction or interacting drug (eg, cimetidine, erythromycin) Usual serum half-life of theophylline is 4–6 h; this may increase to > 20 h after overdose Caffeine in energy drinks or herbal or dietary supplement products can produce similar toxicity + Clinical Findings Download Section PDF Listen +++ ++ Mild intoxication Nausea Vomiting Tachycardia Tremulousness Severe intoxication (serum levels > 100 mg/L [555 mcmol/L]) Ventricular and supraventricular tachyarrhythmias Hypotension Seizures Status epilepticus is common and often intractable to usual anticonvulsants Symptoms may be delayed for hours after acute ingestion, especially if a sustained-release preparation was taken Serious toxicity may develop at lower levels (40–60 mg/L [222–333 mcmol/L]) with chronic intoxication + Diagnosis Download Section PDF Listen +++ ++ Serum theophylline concentration Hypokalemia, hyperglycemia, and metabolic acidosis are common after acute overdose + Treatment Download Section PDF Listen +++ ++ Activated charcoal Give after acute ingestion 60–100 g orally or via gastric tube, mixed in aqueous slurry Do not use for comatose or convulsing patients unless it can be given by gastric tube and airway is protected by a cuffed endotracheal tube Repeat doses may enhance gut decontamination and elimination by "gut dialysis" Consider whole-bowel irrigation for large ingestions of sustained-release preparations Indications for hemodialysis Status epilepticus Markedly elevated serum theophylline levels (eg, > 100 mg/L [555 mcmol/L] after acute overdose or possibly for levels > 60 mg/L [333 mcmol/L] with chronic intoxication) Treatment of seizures Lorazepam, 2–3 mg intravenously Diazepam, 5–10 mg intravenously Phenobarbital, 10–15 mg/kg intravenously Phenytoin is not effective Hypotension and tachycardia may respond to beta-blocker therapy even in low doses Esmolol, 25–50 mcg/kg/min by intravenous infusion Propranolol, 0.5–1.0 mg intravenously