Precautions

Drug information provided by: Merative, Micromedex®

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to decide if you should continue to take it. Blood and urine tests may be needed to check for unwanted effects.

Under certain conditions, too much metformin can cause lactic acidosis. It usually occurs when other serious health problems are present, such as a heart attack or kidney failure. Symptoms of lactic acidosis include stomach discomfort, decreased appetite, diarrhea, fast or shallow breathing, a general feeling of discomfort, muscle pain or cramping, and unusual sleepiness, tiredness, or weakness. If you have more than one of these symptoms together, you should get immediate emergency medical help.

Do not let yourself get dehydrated. Be sure to drink extra fluids when you exercise or increase your activity, or if you have vomiting or diarrhea.

Pancreatitis (swelling and inflammation of the pancreas) may occur while you are using this medicine. Check with your doctor right away if you have a sudden and severe stomach pain, chills, constipation, nausea, vomiting, loss of appetite, fever, or lightheadedness.

Check with your doctor right away if you have chest pain or tightness, decreased urine output, dilated neck veins, extreme fatigue, irregular breathing, irregular heartbeat, swelling of the face, fingers, feet, or lower legs, trouble breathing, or weight gain. These may be signs of heart failure.

This medicine may cause serious allergic reactions, including anaphylaxis, angioedema, or certain skin conditions (eg, Stevens-Johnson syndrome), which can be life-threatening and require immediate medical attention. Call your doctor right away if you have blistering, peeling, or loosening of the skin, chest tightness, chills, cough, diarrhea, difficulty swallowing, dizziness, fast heartbeat, hives, itching, skin rash, joint or muscle pain, large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs, puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, or unusual tiredness or weakness while you are using this medicine.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine before having a major surgery or diagnostic tests, especially tests that use a contrast dye.

It is very important to carefully follow any instructions from your health care team about:

  • Alcohol—Drinking alcohol may cause severe low blood sugar. Discuss this with your health care team.
  • Other medicines—Do not take other medicines unless they have been discussed with your doctor. This especially includes nonprescription medicines, such as aspirin, and medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems.
  • Counseling—Other family members need to learn how to prevent side effects or help with side effects if they occur. Also, patients with diabetes may need special counseling about the changes in the dosing of their diabetes medicine that might occur with lifestyle changes, such as changes in exercise or diet. Furthermore, counseling on contraception and pregnancy may be needed, because of the problems that can occur in patients with diabetes during pregnancy.
  • Travel—Keep a recent prescription and your medical history with you. Be prepared for an emergency as you would normally. Make allowances for changing time zones and keep your meal times as close as possible to your usual meal times.
  • In case of emergency—There may be a time when you need emergency help for a problem caused by your diabetes. You need to be prepared for these emergencies. It is a good idea to wear a medical identification (ID) bracelet or neck chain at all times. Also, carry an ID card in your wallet or purse that says you have diabetes and that lists all of your medicines.

This medicine may cause hypoglycemia (low blood sugar). This is more common when this medicine is taken together with certain medicines. Low blood sugar must be treated before it causes you to pass out (unconsciousness). It is important that you learn which symptoms you usually have so you can treat it quickly. Some symptoms of low blood sugar include: behavior changes that are similar to being drunk, blurred vision, cold sweats, confusion, cool, pale skin, difficulty with thinking, drowsiness, excessive hunger, a fast heartbeat, headaches that continue, nausea, shakiness, slurred speech, or unusual tiredness or weakness. Talk to your doctor about how to treat low blood sugar.

Hyperglycemia (high blood sugar) may occur if you do not take enough or skip a dose of your medicine, overeat or do not follow your meal plan, have a fever or infection, or do not exercise as much as usual. High blood sugar can be very serious and must be treated right away. It is important that you learn which symptoms you have in order to treat it quickly. Talk to your doctor about the best way to treat high blood sugar.

This medicine may cause severe and disabling joint pain. Call your doctor right away if you have severe joint pain while using this medicine.

This medicine may cause bullous pemphigoid. Tell your doctor right away if you have large, hard skin blisters while you are using this medicine.

Limit the amount of alcohol you drink while you are using this medicine. Heavy alcohol use can increase your chances of serious side effects.

This medicine may cause some women who do not have regular monthly periods to ovulate. This can increase the chance of pregnancy. If you are a woman of childbearing potential, you should discuss birth control options with your doctor.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

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Portions of this document last updated: May 01, 2024

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