Drug adverse effect report: acute psychosis with co-amoxiclav
This case report in the BMJ ‘Drug Points’ strand describes symptoms of acute psychosis in a female patient treated with oral co-amoxiclav.
The patient received co-amoxiclav 375mg orally and within two hours became disorientated and confused. She presented to A&E, however by this time symptoms had resolved and examination was normal. Later the same day she received a further dose of 750mg and within 90 minutes her behaviour became increasingly agitated and bizarre, with visual hallucinations, persecutory delusions, and disordered speech. Her symptoms resolved on haloperidol plus midazolam and did not recur. A diagnosis was made, and examination of her hospital notes found that she had previously experienced hallucinations related to a single dose of co-amoxiclav given as surgical prophylaxis.
The authors note that there have been previous reports of psychiatric adverse effects with co-amoxiclav and also with amoxicillin, suggesting that this component is responsible. They caution that the possibility of drug-induced psychosis should be considered, even in the absence of pre-existing psychiatric illness or predisposing factors.
BMJ 2008;337:a1789 (link to extract)