physician. He also continued insulin therapy for 3 months, when his physician changed the
regimen to pioglitazone 30 mg/day and metformin 250 mg twice/day. The change was made
because it became difficult for the patient's family to constantly monitor his insulin
regimen, glucose levels, and insulin compliance. After 1 week, hypoglycemia-like symptoms
reportedly developed, and metformin was discontinued. The patient's condition remained
relatively well controlled with pioglitazone monotherapy. Approximately 6 months later,
his fasting {*filter*} glucose level was 122 mg/dl, hemoglobin A1c 7.5% (normal < 6%), and
weight 171 pounds.

Literature Review
Several case reports of olanzapine-associated diabetes mellitus, as well as some pilot
clinical investigations of the effects of olanzapine on glucose regulation, have been
published.[5-16] One report stated that postmarketing surveillance had documented 139
cases of diabetes associated with olanzapine.[13] However, only a fraction of these case
reports have been published. A synopsis of key published case reports is presented in
Table 1.
A patient with diabetes previously controlled with diet experienced severe glucose
dysregulation only 3 weeks after starting olanzapine.[5] Therapy with {*filter*}agents was
tried but was not successful, and insulin eventually was started. Olanzapine was replaced
with quetiapine, but hyperglycemia continued. Both {*filter*} were discontinued, which resulted
in decreased insulin requirements.

In two instances,[6] one previously reported,[7] glucose dysregulation occurred within 12
weeks after olanzapine was begun. Insulin was discontinued in both patients 21 and 25 days
after withdrawal of olanzapine. Glucagon tests indicated that both patients had depressed
endogenous insulin secretion during therapy compared with test results 1 month after
discontinuation.

Diabetic ketoacidosis associated with olanzapine developed in a patient with no personal
or family history of diabetes.[7] The patient lost weight while taking olanzapine, and
laboratory tests indicated the presence of ketones in urine and serum. Due to
hypoglycemia, insulin was discontinued 15 days after olanzapine was stopped.

Glycemic control was severely altered in a patient previously well controlled with proper
diet and glyburide 5 mg/day.[8] Glucose readings were elevated within 1 month after
starting olanzapine. Insulin was added after the dosage of his {*filter*}agents was increased.
The patient also experienced severe edema and weight gain, elevated lipid levels, and