title: First-degree atrioventricular block in alprazolam overdose reversed by flumazenil.
abstract: This report describes a case of alprazolam overdose associated with marked first-degree atrioventricular block reversed by flumazenil. Animal and human evidence suggests activity of certain benzodiazepines at peripheral benzodiazepine receptors in the myocardium and elsewhere. Myocardial benzodiazepine receptor ligands appear to affect calcium-channel activity, which may explain the clinical findings. Benzodiazepines may behave like weak calcium-channel blockers. This case raises the possibility of a potential role for flumazenil as an adjunct in the management of calcium-channel blocker toxicity.
authors.affiliation: Oregon Poison Center, Department of Emergency Medicine, Oregon Health Sciences University, Portland 97201-3098, USA. mullinmi@ohsu.edu
authors.forename: M E
authors.initials: ME
authors.lastname: Mullins
mesh_terms: D000328:Adult; D000525:Alprazolam / Q000506:poisoning*; D014151:Anti-Anxiety Agents / Q000009:adverse effects; D000931:Antidotes / Q000627:therapeutic use*; D004562:Electrocardiography; D005442:Flumazenil / Q000627:therapeutic use*; D006327:Heart Block / Q000139:chemically induced / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008508:Medication Errors / Q000009:adverse effects*
chemical_list: D014151:Anti-Anxiety Agents; D000931:Antidotes; D005442:Flumazenil; D000525:Alprazolam