There are in the literature a few case reports about the development of a manic-psychotic features after the use of antibiotics.This side effect is compared to the frequent and widespread use not very common.

Awareness about the potential neuropsychiatric side effects of antibiotics.

A 53 year old man was seen with since two days manifest agitation, religious utterances, confusion, sleep disturbance and sexual disinheriting. He started ten days before admission a course with Amoxicillin / Clavulanic-acid 500/125 mg t.i.d. for erysipelas to the right leg. He seems to be manic psychotic. During the hospitalization he refused to take the prescribed risperidon. He took only the lorazepam. On the third hospital day the psychiatric symptoms were fully remitted. He had two years ago the same psychiatric symptoms after a seven-day treatment with cotrimoxazole. His condition is completely disappeared within 24 hours after cotrimoxazol discontinuation and without any intake of psychotropic drugs. Pathophysiology: Unclear. Possibly interact antibiotics with different neurotransmitters: for example penicillin inhibits GABA- A and benzodiazepine receptors. This leads to a stimulation of the central nervous system resulting in neurotoxicity and reduction of the seizure threshold. The inhibition of the hepatic P450 enzyme system which results in increased serum levels of antibiotics and subsequently to neurotoxicity. Prostaglandins and cortisol may also play a role.

Manic-psychosis as a side-effect of antibiotics is rare and the symptoms usually disappear within a few days after stopping the antibiotic and a treatment with psychotropic drugs is usually not necessary.