Introduction:
People with schizophrenia are at increased risk of developing metabolic disturbances. This risk may be further exacerbated by the use of antipsychotic agents. Research is still ongoing to determine the metabolic impact of antipsychotics on glucose regulation. In this case report we review some of the possible mechanisms of action of antipsychotic medication on glucose regulation.

Case presentation:
We present the case of a 50-year-old man diagnosed with paranoid schizophrenia who developed type 2 diabetes mellitus whilst on treatment with second generation antipsychotics (SGA). His diabetes was controlled by a combination of antidiabetic drugs that were associated with his psychotropic treatment. Due to deterioration in his mental state, the patient was admitted on two occasions to a psychiatric unit during which his prescribed medication (olanzapine and risperidone) was discontinued and changed to aripiprazole. On both occasions, the patient suffered hypoglycaemic episodes and his antidiabetic treatment had to be adjusted accordingly. The patient did not require any antidiabetic treatment whilst on aripiprazole during the follow up period.

Conclusion:
Clinicians face regular dilemmas in trying to find the right balance between achieving control over a patient's mental illness and reducing any adverse effects associated with the prescribed medication. In patients receiving concomitant antidiabetic therapy, caution should be exercised when changing from one SGA to another. Whilst more longitudinal data are required, a trial of alternative SGAs, including aripiprazole in those developing type 2 diabetes and impaired glucose tolerance may be a worthwhile therapeutic option.