Metformin and sitagliptin are oral diabetes medicines that help control blood sugar levels.

Metformin works by decreasing glucose (sugar) production in the liver and decreasing absorption of glucose by the intestines. Sitagliptin works by regulating the levels of insulin your body produces after eating.

Metformin and sitagliptin is a combination medicine that is used together with diet and exercise to improve blood sugar control in adults with type 2 diabetes mellitus. This medicine is not for treating type 1 diabetes.

Metformin and sitagliptin may also be used for purposes not listed in this medication guide.

You should not use this medicine if you are allergic to metformin or sitagliptin (Januvia), or if you have severe kidney disease or diabetic ketoacidosis (call your doctor for treatment with insulin).

Tell your doctor if you have ever had:

• kidney disease (your kidney function may need to be checked before and while you are taking this medicine);
• liver disease;
• heart disease;
• pancreatitis;
• high triglycerides (a type of fat in the blood);
• gallstones; or
• alcoholism.

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. This may be more likely if you have other medical conditions, a severe infection, chronic alcoholism, or if you are 65 or older. Ask your doctor about your risk.

If you need to have surgery or any type of x-ray or CT scan using a dye that is injected into your veins, you may need to temporarily stop taking metformin and sitagliptin. Be sure your caregivers know ahead of time that you are using this medication.

Follow your doctor's instructions about using this medicine if you are pregnant or you become pregnant. Controlling diabetes is very important during pregnancy, and having high blood sugar may cause complications in both the mother and the baby.

Metformin may stimulate ovulation in a premenopausal woman and may increase the risk of unintended pregnancy. Talk to your doctor about your risk.

It may not be safe to breastfeed while using this medicine. Ask your doctor about any risk.

This medicine is not approved for use by anyone younger than 18 years old.

Use Janumet XR (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).

Stop taking this medicine and call your doctor right away if you have symptoms of pancreatitis: severe pain in your upper stomach spreading to your back, nausea and vomiting, loss of appetite, or fast heartbeats.

Some people using metformin develop lactic acidosis, which can be fatal. Get emergency medical help if you have even mild symptoms such as:

• unusual muscle pain;
• feeling cold;
• trouble breathing;
• feeling dizzy, light-headed, tired, or very weak;
• stomach pain, vomiting; or
• irregular heart rate.

Call your doctor at once if you have any of these serious side effects:

• severe autoimmune reaction--itching, blisters, breakdown of the outer layer of skin;
• severe or ongoing pain in your joints;
• little or no urinating; or
• symptoms of heart failure--shortness of breath (even while lying down), swelling in your legs or feet, rapid weight gain.

Common side effects may include:

• low blood sugar (if you also use insulin or another oral diabetes medication);
• upset stomach, indigestion, gas, diarrhea, nausea, vomiting;
• headache, weakness; or
• cold symptoms such as runny or stuffy nose, sneezing, sore throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid drinking alcohol. It lowers blood sugar and may increase your risk of lactic acidosis.