Metformin
Reduces insulin resistance and glucose production in the liver through AMPK activation.
- Weight gain on antipsychotics1
- Prolactinemia on antipsychotics
- Hypertriglycerides on antipsychotics
Features
Dosing
Start 500 mg qd with food x 7 days then 1,000 mg qd. Use XR to prevent nausea.
Management
Works better when started early to prevent weight gain. Have patient weight themselves (naked, in morning, after using bathroom and before breakfast) before starting antipsychotic and again 1 month later. If they experience > 5% weight gain, start metformin.
Improves mood in diabetes. Antiaging effects.
TOLERABILITY: Nausea, gas, diarrhea, fatigue.
RISKS: Vitamin B12 deficiency with long-term use. Rare lactic acidosis.
EMR Text
Weight gain on antipsychotics
Metformin use based on APA treatment guidelines for antipsychotic weight gain, where it also improves insulin sensitivity, prolactin, and triglyceride levels.
Metformin side effects reviewed with patient, including B12 deficiency and lactic acidosis.