Acute psychosis after amantadine overdose

Area of Science:

• Pharmacology
• Neurology
• Toxicology

Background:

• Amantadine is an antiviral medication also prescribed for Parkinsonism and drug-induced movement disorders.
• Central nervous system toxicity is a known side effect of amantadine, ranging from mild symptoms to severe disorientation and hallucinations.

Observation:

• A case study details a previously healthy 35-year-old woman presenting with acute psychosis.
• Her symptoms included delirium and visual hallucinations, indicative of severe central nervous system effects.

Findings:

• The patient's psychosis was attributed to an unsuspected amantadine overdose.
• Concomitant use of diphenhydramine, an anticholinergic agent, was identified as a contributing factor to the severity of her presentation.

Implications:

• Amantadine toxicity should be considered in the differential diagnosis of altered mental status, especially in patients with known amantadine use or relevant medical conditions.
• Healthcare providers should be vigilant about potential amantadine toxicity, particularly when anticholinergic medications are co-administered.
• This case highlights the importance of a thorough medication history in diagnosing acute psychosis.