Janumet (Sitagliptin/Metformin)

(℞) Prescription Required

    Janumet (Sitagliptin/Metformin) Dosage and Side Effects

    JANUMET or JANUMET XR are used in addition to diet and exercise to improve blood sugar levels in patients with type 2 diabetes mellitus.

    Warnings and Precautions

    Serious Warnings and Precautions

    JANUMET and JANUMET XR contain metformin which can rarely cause lactic acidosis. Lactic acidosis can cause death and must be treated in the hospital (see section Lactic Acidosis: below). Since alcohol may increase the risk of lactic acidosis caused by metformin you should not drink a lot of alcohol if you take JANUMET and JANUMET XR (see section Lactic Acidosis: below).

    Lactic Acidosis:

    Stop taking JANUMET or JANUMET XR if you get the following symptoms of lactic acidosis:

    • You feel very weak and tired.
    • You have unusual (not normal) muscle pain.
    • You have trouble breathing.
    • You have stomach pain with nausea and vomiting, or diarrhea.
    • You feel cold, especially in your arms and legs.
    • You feel dizzy or lightheaded.
    • You have a slow or irregular heartbeat.
    • Your medical condition suddenly changes.

    You have a higher chance of getting lactic acidosis if you:

    • Have kidney problems.
    • Have congestive heart failure that requires treatment with medicines.
    • Drink a lot of alcohol (very often or short-term “binge” drinking).
    • Get dehydrated (lose a large amount of body fluids). This can happen if you are sick with a fever, vomiting, or diarrhea. Dehydration can also happen when you sweat a lot with activity or exercise and don't drink enough fluids.
    • Have certain x-ray tests with injectable dyes or contrast agents used.
    • Have surgery.
    • Have a heart attack, severe infection, or stroke.
    • Are 80 years of age or older and have not had your kidney function tested.

    Cases of inflammation of the pancreas (pancreatitis) which may be severe and lead to death have been reported in patients taking JANUMETor JANUMET XR.

    BEFORE or while taking JANUMET or JANUMET XR talk to your physician or pharmacist if:

    • You have or have had pancreatitis (inflammation of the pancreas) or any risk factors for pancreatitis such as gallstones (solid particles that form in the gall bladder), a history of alcoholism, high triglyceride levels.
    • You are receiving treatment with insulin since this drug can increase the risk of hypoglycemia (low blood sugar). When JANUMETor JANUMET XR is used in combination with sulfonylurea or insulin, low blood sugar can occur. Your physician may consider lowering the dose of the sulfonylurea or insulin. Take precautions to avoid low blood sugar while driving or using machinery.
    • You have or have had an allergic reaction to sitagliptin, metformin, JANUMET or JANUMET XR.
    • You have heart problems including congestive heart failure (a condition where your heart becomes weaker and less able to pump the blood that your body needs).
    • You have or have had kidney problems.
    • You have liver problems.
    • Drink alcohol a lot (all the time or short-term “binge” drinking).
    • You are pregnant or plan to become pregnant. JANUMET or JANUMET XR are not recommended for use during pregnancy.
    • You are breast-feeding or plan to breast-feed. You should not use JANUMET or JANUMET XR if you are breast feeding. It is not known if JANUMET or JANUMET XR passes into breast milk.
    • Are older than 80 years. Patients over 80 years should not take JANUMET or JANUMET XR unless their kidney function is checked and it is normal.

    JANUMET and JANUMET XR are not recommended for use in children under 18 years of age.

    Side Effects

    Like all medicines, JANUMET and JANUMET XR may cause side effects.

    The most common side effects in patients taking sitagliptin alone include: stuffy or runny nose and sore throat.

    Common side effects of metformin include: diarrhea, nausea, upset stomach, abdominal bloating, gas, loss of appetite. Similar adverse experiences were seen in patients treated with extended-release metformin products.

    In rare cases, metformin, one of the medicines in JANUMET and JANUMET XR, can cause a serious side effect called lactic acidosis. This is caused by a buildup of lactic acid in your blood. This build-up can cause serious damage. You should also stop using JANUMET or JANUMET XR and call your physician right away if you have signs of lactic acidosis. Lactic acidosis is a medical emergency that must be treated in a hospital.

    When JANUMET or JANUMET XR is used with a sulfonylurea medicine or with insulin, low blood sugar (hypoglycemia) can occur. Lower doses of the sulfonylurea medicine or insulin may be required while you used JANUMET or JANUMET XR. The signs and symptoms of low blood sugar may include headache, drowsiness, weakness, dizziness, confusion, irritability, hunger, fast heartbeat, sweating, and feeling jittery. Discuss with your physician or pharmacist how to treat low blood sugar.

    Tell your physician or pharmacist if you develop any unusual side effect, or any of the above side effects that do not go away or get worse.

    Additional side effects have been reported in general use with JANUMET, JANUMET XR or sitagliptin, one of the medicines in JANUMET or JANUMET XR. These side effects have been reported when JANUMET, JANUMET XR or sitagliptin have been used by themselves and/or with other diabetes medicines:

    • Allergic reactions, which may be serious, including rash, hives, and swelling of the face, lips, tongue, and throat that may cause difficulty in breathing or swallowing. If you have an allergic reaction, stop taking JANUMET or JANUMET XR and call your physician right away. Your physician may prescribe a medication to treat your allergic reaction and a different medication for your diabetes.
    • Inflammation of the pancreas.
    • Kidney problems (sometimes requiring dialysis).
    • Constipation.
    • Vomiting.
    • Headache.
    • Joint pain.
    • Muscle aches.
    • Arm or leg pain.
    • Back pain.
    • Itching.
    • Blisters.

    Interactions with this medication

    Some drugs may interact with JANUMET or JANUMET XR. Careful monitoring is advised. Tell your doctor if you are taking:

    • other diabetes drugs such as glyburide
    • furosemide
    • nifedipine
    • cationic drugs (e.g., amiloride, digoxin, morphine, procainamide, quinidine, quinine, ranitidine, triamterene, trimethoprim, and vancomycin)
    • other drugs tend to produce hyperglycemia (high blood sugar) and may lead to a loss of blood sugar control. Some example of drugs that can increase the blood sugar include:
      • Thiazide and other diuretics (water pills)
      • Corticosteroids
      • Phenothiazines
      • Thyroid products
      • Estrogens or estrogens plus progestogen
      • Oral contraceptives
      • Phenytoin
      • Nicotinic Acid
      • Sympathomimetics
      • Calcium channel blocking drugs
      • Isoniazid
      • Beta-2-agonists
    • ACE inhibitor drugs may lower blood glucose and the combination with JANUMET or JANUMET XR should be carefully monitored.

    Before using any drugs or herbal products, check with your physician or your pharmacist.

    Proper Use of this medication

    Take JANUMET or JANUMET XR exactly as your physician has prescribed. Your physician will tell you how many JANUMET or JANUMETXR tablets to take and how often you should take them.

    Your physician may need to increase your dose to control your blood sugar.

    Usual dose:

    JANUMET should generally be given twice daily with meals to lower your chance of an upset stomach.

    JANUMET XR should be taken once a day with food preferably in the evening to lower your chance of an upset stomach.

    If you take JANUMET XR, swallow the JANUMET XR tablets whole. Do not chew, cut, or crush the tablets. Tell your doctor if you cannot swallow JANUMET XR whole.

    Very rarely, you may see something that looks like the JANUMET XR tablet in your stool (bowel movement). If this happens, check your blood sugar. If your blood sugar control has changed, contact your doctor. Do not stop taking JANUMET XR without talking to your doctor.

    Continue to take JANUMET or JANUMET XR as long as your physician prescribes it so you can continue to help control your blood sugar.

    You may need to stop JANUMET or JANUMET XR for a short time. Call your physician for instructions if you:

    • have a condition that may be associated with dehydration (large loss of body fluids) such as being sick with severe vomiting, diarrhea or fever, or if you drink fluids a lot less than normal.
    • plan to have surgery.
    • are going to get or receive an injection of dye or contrast agent for an x-ray procedure.


    In case of drug overdose, contact a health care practitioner, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.

    Missed dose:

    If you miss a dose, take it with food as soon as you remember. If you do not remember until it is time for your next dose, skip the missed dose and go back to your regular schedule. Do not take two doses of JANUMET or JANUMET XR at the same time.

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    The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.