dextromethorphan and Dystonia

Topics: Antitussive Agents; Dextromethorphan; Diagnosis, Differential; Drug Evaluation, Preclinical; Dystonia; Emergency Service, Hospital; False Positive Reactions; Female; Humans; Infant; Phencyclidine; Poisoning; Risk Assessment; Unconsciousness; Urine

The effects of dextromethorphan and its metabolite dextrorphan on severity of dystonia were examined in mutant dystonic hamsters, an animal model of idiopathic paroxysmal dystonia, in which recent examinations have shown antidystonic effects of selective N-methyl-D-aspartate (NMDA) receptor antagonists. Dextromethorphan and dextrorphan are non-competitive NMDA receptor antagonists which additionally exhibit affinity for sigma receptors. Dextrorphan (20 and 40 mg/kg i.p.) significantly retarded the progression of dystonia at the higher dose, whereas dextromethorphan (20, 40, 60 mg/kg i.p.) failed to exert any antidystonic effects even at high doses which caused severe effects. The lack of antidystonic efficacy of dextromethorphan may be related to its higher affinity to sigma receptors compared with dextrorphan.

Topics: Animals; Antitussive Agents; Cricetinae; Dextromethorphan; Dextrorphan; Disease Progression; Dystonia; Neuroprotective Agents; Receptors, N-Methyl-D-Aspartate; Receptors, sigma

Accidental ingestions of cough and cold preparations containing dextromethorphan (DM) are common in the toddler age group and rarely have serious consequences. Even large intentional overdoses by adults seldom lead to serious morbidity. There have been no previous reports of an extrapyramidal reaction due to a DM ingestion.. We report a 30-month-old girl who ingested approximately 38 mg/kg dextromethorphan. She presented with opisthotonus, ataxia, and bidirectional nystagmus. There was no change in her status with the administration of naloxone. The child was given diphenhydramine with clearing of her opisthotonus but persistence of her ataxia and nystagmus.. A moderate ingestion of dextromethorphan in a toddler resulted in extrapyramidal symptoms with opisthotonus that responded to diphenhydramine. Dextromethorphan is known to have complex CNS effects and, in sufficient doses, may have dopamine receptor blocking activity resulting in this dystonic reaction.

Topics: Antidotes; Antitussive Agents; Ataxia; Child, Preschool; Dextromethorphan; Diphenhydramine; Dystonia; Female; Humans; Nystagmus, Pathologic; Poisoning

Topics: Antitussive Agents; Child; Dextromethorphan; Dystonia; Humans; Male