Psychosis with onset in late adulthood already constitutes a challenge on the differential diagnosis and treatment, especially in polypharmacy patients.

We present a case report of a 61-year old woman with a late-onset psychosis and discuss the clinical evolution and the pharmacological treatment.

The patient suffered from obesity, type II diabetes mellitus with poor glycemic control, and hypertension. She had a first psychotic episode at the age of 56, having persecutory delusional ideas and auditory hallucinations with psychomotor agitation and insomnia. She was first medicated with an atypical antipsychotic (olanzapine) with little response and worsening of the glycemic control. A switch was performed to haloperidol with remission of symptomatology with low doses (4 mg/day). Through follow-up the doses of haloperidol was decreased and eventually suspended, but having a relapse a few months later. Haloperidol was again introduced and the symptoms remitted. Stability was maintained, but the patient started to show lower limbs symmetrical rigidity and psychomotor retardation. It was decided to switch haloperidol to risperidone, but the patient reported side effects with its use, and had to stop it. Haloperidol was again introduced, but had to be discontinued after motor symptoms got worse. Again the patient had another recurrence of psychotic symptoms and it was decided to introduce paliperidone (6 mg/day) with good response and tolerability.

The safety and tolerability of antipsychotic medication is variable. When choosing a treatment in a patient with comorbid medical conditions, it can severely influence the desirable outcome.

The authors have not supplied their declaration of competing interest.