Two cases of agranulocytosis occurring after addition of a butyrophenone to a course of phenothiazine treatment are reported and possible mechanisms for this interaction are discussed. Agranulocytosis is a well-documented adverse effect of phenothiazine administration (Vincent, 1986). Important factors are the total amount of drug given and the duration of administration. Agranulocytosis usually occurs within the first three months of therapy (Pisciotta, 1971; Marcus & Mulvihill, 1978) and the relationship with the cumulative dose has been emphasised (Ananth et al, 1973). Agranulocytosis following prolonged administration has been rarely reported (Denber, 1970, Pisciotta, 1978). We report two cases where agranulocytosis developed in patients with a long previous exposure to phenothiazines, treated for the first time with a combination of phenothiazines and a butyrophenone.

A 27-year-old neuroleptic-stabilised schizophrenic patient presented with a three-day history of psychomotor retardation, disturbed sleep, and social and emotional withdrawal following reduction of his anticholinergic dosage; his symptoms had intensified after an increase in neuroleptic dosage, based on a diagnosis of psychotic decompensation. Recognition of a cholinergic syndrome and institution of appropriate anticholinergic treatment resulted in rapid improvement. The clinical distinction between a cholinergic overdrive state and schizophrenic exacerbation, while sometimes difficult, can be critical in selecting appropriate management.

A patient with de Clérambault's syndrome (erotomania) following brain damage and epilepsy is described. The delusion appeared after brain surgery for subarachnoid haemorrhage, and remained chronic. Erotomania in this patient may be judged to be aetiologically related to organic brain damage.

The case of a young, unmarried boy, who had moderate mental retardation, epilepsy, and post-ictal psychosis, is described here. During the psychosis, he believed he was pregnant, and had related behavioural disturbances. The review of other such cases reveals that organic brain damage was evident in all cases. Brain damage seems to be the more likely causative factor than psychodynamic factors.