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metformin and sitagliptin

Generic Name: metformin and sitagliptin (met FOR min and SI ta glip tin)
Brand Name: Janumet, Janumet XR

What is metformin and sitagliptin?

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.

What is the most important information I should know about metformin and sitagliptin?

You should not use this medicine if you have severe kidney disease or diabetic ketoacidosis (call your doctor for treatment with insulin).

This medicine may cause a serious condition called lactic acidosis. Get emergency medical help if you have even mild symptoms such as: muscle pain or weakness, numb or cold feeling in your arms and legs, trouble breathing, stomach pain, nausea with vomiting, slow or uneven heart rate, dizziness, or feeling very weak or tired.

What should I discuss with my health care provider before taking metformin and sitagliptin?

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).

Some people taking metformin develop a serious condition called lactic acidosis. This may be more likely if you have liver or kidney disease, congestive heart failure, a heart attack or stroke, a severe infection, if you are 65 or older, if you are dehydrated, or if you drink a lot of alcohol. Talk with your doctor about your risk.

To make sure metformin and sitagliptin is safe for you, tell your doctor if you have:

  • kidney disease (your kidney function may need to be checked before you take this medicine);

  • liver disease;

  • a history of heart disease;

  • pancreatitis;

  • high triglycerides (a type of fat in the blood);

  • gallstones;

  • a history of alcoholism; or

  • if you are over 80 years old and have not recently had your kidney function checked.

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 will need to temporarily stop taking metformin and sitagliptin. Be sure your caregivers know ahead of time that you are using this medication.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

It is not known whether metformin and sitagliptin passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

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

How should I take metformin and sitagliptin?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take metformin and sitagliptin with meals.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

Janumet tablets may not completely dissolve in the body. Part of the tablet may appear in your stool. This is a normal side effect of Janumet and will not make the medicine less effective.

Call your doctor if you see a tablet in your stool several times.

Low blood sugar (hypoglycemia) can happen to everyone who has diabetes. Symptoms include headache, hunger, sweating, irritability, dizziness, nausea, fast heart rate, and feeling anxious or shaky. To quickly treat low blood sugar, always keep a fast-acting source of sugar with you such as fruit juice, hard candy, crackers, raisins, or non-diet soda.

Your doctor can prescribe a glucagon emergency injection kit to use in case you have severe hypoglycemia and cannot eat or drink. Be sure your family and close friends know how to give you this injection in an emergency.

Also watch for signs of high blood sugar (hyperglycemia) such as increased thirst or urination, blurred vision, headache, and tiredness.

Blood sugar levels can be affected by stress, illness, surgery, exercise, alcohol use, or skipping meals. Ask your doctor before changing your dose or medication schedule.

Metformin and sitagliptin is only part of a complete treatment program that may also include diet, exercise, weight control, regular blood sugar testing, and special medical care. Follow your doctor's instructions very closely.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember (be sure to take the medicine with food). Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. You may have signs of low blood sugar, such as extreme weakness, blurred vision, sweating, trouble speaking, tremors, stomach pain, confusion, and seizure (convulsions).

What should I avoid while taking metformin and sitagliptin?

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

Metformin and sitagliptin side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

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 develop lactic acidosis while taking metformin. Early symptoms may get worse over time and this condition can be fatal. Stop taking this medicine and get emergency medical help if you have even mild symptoms such as:

  • muscle pain or weakness;

  • numb or cold feeling in your arms and legs;

  • trouble breathing;

  • feeling dizzy, light-headed, tired, or very weak;

  • stomach pain, nausea with vomiting; or

  • slow or uneven 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;

  • heart problems--shortness of breath (even while lying down), feeling weak or tired, rapid weight gain, swelling (especially in your feet, legs, or midsection); or

  • severe skin reaction--fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common side effects may include:

  • upset stomach, 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.

See also: Side effects (in more detail)

Metformin and sitagliptin dosing information

Usual Adult Dose for Diabetes Type 2:

Dose should be individualized based on patient's current regimen, effectiveness, and tolerability.
Maximum dose: Metformin 2000 mg-sitagliptin 100 mg orally daily

Metformin-sitagliptin immediate release:
-Patients not currently treated with metformin: Metformin 500 mg-sitagliptin 50 mg orally twice a day

-Patients already treated with metformin: Sitagliptin 50 mg and the dose of metformin previously prescribed (500 mg or 1000 mg) orally twice a day. Metformin 1000 mg-sitagliptin 50 mg orally twice a day is recommended for patients already taking metformin 850 mg orally twice a day.

Metformin-sitagliptin extended release:
-Patients not currently treated with metformin: Metformin 1000 mg-sitagliptin 100 mg orally once a day

-Patients already treated with metformin: Sitagliptin 100 mg and the dose of metformin previously prescribed (500 mg or 1000 mg) once a day. For patients taking metformin immediate-release 850 mg or 1000 mg twice a day, the recommended dose is two tablets of sitagliptin metformin 1000 mg-50 mg sitagliptin taken together once a day.

Patients changing between immediate-release and extended-release: Maintain the same daily dose of metformin-sitagliptin

Comments: Co-administration of metformin-sitagliptin with an insulin secretagogue (e.g., sulfonylurea) or insulin may require lower doses of insulin secretagogue or insulin to reduce the risk of hypoglycemia.

What other drugs will affect metformin and sitagliptin?

Many drugs can interact with metformin and sitagliptin. Some drugs can affect how well metformin and sitagliptin controls your blood sugar. Other drugs may increase your risk of lactic acidosis. Not all possible interactions are listed in this medication guide. Tell your doctor about all medicines you use, and those you start or stop using. Give a list of all your medicines to any healthcare provider who treats you.

Where can I get more information?

  • Your pharmacist can provide more information about metformin and sitagliptin.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 6.07.

Last reviewed: January 30, 2017
Date modified: May 03, 2017

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