Aims: Atypical anti-psychotic drugs (APDs) are widely used in psychotic disorders refractory to conventional neuroleptic agents.
Results: Three cases of new-onset diabetes are reported in Caucasian men who were on clozapine (one) or olanzapine (two) for 3-6 months. They had a distinct presentation: weight loss, ketosis (one ketoacidosis), severe hyperglycaemia requiring insulin therapy, and relative insulin deficiency as reflected by glucagon stimulatory tests. In all cases, insulin was stopped within 1 month after the APD was discontinued.
Conclusions: Novel APDs not only induce diabetes as a result of weight gain in predisposed patients, but can also lead to a reversible state of insulin deficiency, and sometimes ketoacidosis.