Abstract

Clidinium bromide (N-methyl-quinuclidinyl-benzylate) is a rarely used antimuscarinic drug that is marketed in combination with chlordiazepoxide as an antispasmodic for use in irritable bowel syndrome. A case is reported of an accidental staggered overdose of clidinium bromide 50 mg in a patient using illicit chlordiazepoxide. The presenting features were mildly dilated pupils and palpitation secondary to sinus tachycardia that persisted for 11 h after the time of first ingestion. Emergency physicians should be aware of the potential for antimuscarinic toxicity in patients using illicit chlordiazepoxide.