What other drugs affect Fortamet (Metformin)?
You may be more likely to have hyperglycemia (high blood sugar) if you are taking metformin with other drugs that raise blood sugar. Drugs that can raise blood sugar include: isoniazid diuretics (water pills) steroids (prednisone and others) phenothiazines (Compazine and others) thyroid medicine (Synthroid and others) birth control pills and other hormones seizure medicines (Dilantin and others); and diet pills, or medicines to treat asthma, colds or allergies You may be more likely to have hypoglycemia (low blood sugar) if you are taking metformin with other drugs that lower blood sugar. Drugs that can lower blood sugar include: some nonsteroidal anti-inflammatory drugs (NSAIDs) aspirin or other salicylates (including Pepto-Bismol) sulfa drugs (Bactrim and others) a monoamine oxidase inhibitor (MAOI) beta-blockers (Tenormin and others); or probenecid (Benemid) Some medications may interact with metformin. Tell your doctor if you are using any of the following drugs: furosemide (Lasix)