It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.
Call your doctor right away if you have chest pain or discomfort; nausea; pain or discomfort in the arms, jaw, back, or neck; shortness of breath; sweating; or vomiting. These may be symptoms of a heart attack.
If you are rapidly gaining weight or having shortness of breath, chest pain or discomfort, extreme tiredness or weakness, irregular breathing, irregular heartbeat, or excessive swelling of the hands, wrist, ankles, or feet, check with your doctor right away. These may be symptoms of a heart problem or edema (fluid retention).
Let your doctor or dentist know you are taking this medicine. Your doctor may advise you to stop taking this medicine before you have major surgery or diagnostic tests, especially tests that use a contrast dye.
Under certain conditions, too much metformin can cause a serious condition called lactic acidosis. The symptoms of lactic acidosis are severe and appear quickly. Lactic acidosis usually occurs when other serious health problems are present, such as a heart attack or kidney failure. The symptoms of lactic acidosis include: abdominal or 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.
If you have abdominal or stomach pain; dark urine; a loss of appetite; nausea or vomiting; unusual tiredness or weakness; or yellow eyes or skin, check with your doctor right away. These may be symptoms of a serious liver problem.
Check with your doctor right away if blurred vision, difficulty in reading, or any other change in vision occurs while you are taking this medicine. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).
Certain women may be at an increased risk for pregnancy while taking this medicine. If you had problems ovulating and had irregular periods in the past, this medicine may cause you to ovulate. This could increase your chance of becoming pregnant. If you are a woman of childbearing potential, you should discuss birth control options with your doctor.
This medicine may increase the risk for bone fractures in women. Ask your doctor about ways to keep your bones strong to help prevent fractures.
Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests.
It is very important to follow carefully any instructions from your doctor about:
- Alcohol—Drinking alcohol may cause severe low blood sugar. Discuss this with your doctor.
- 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 diabetes medicine dosing changes that might occur because of lifestyle changes, such as changes in exercise and 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 that you have diabetes and a list of all of your medicines.
- Symptoms of fluid retention—Know what to do if you start to retain fluid. Fluid retention may worsen or lead to heart problems.
This medicine can cause hypoglycemia (low blood sugar). Low blood sugar can also occur if you delay or miss a meal or snack, exercise more than usual, drink alcohol, or cannot eat because of nausea or vomiting. The symptoms of low blood sugar must be treated before they lead to unconsciousness (passing out). Different people feel different symptoms of low blood sugar. It is important that you learn which symptoms of low blood sugar you usually have so that you can treat it quickly.
- Symptoms of low blood sugar include anxiety; behavior change similar to being drunk; blurred vision; cold sweats; confusion; cool, pale skin; difficulty in thinking; drowsiness; excessive hunger; fast heartbeat; headache (continuing); nausea; nervousness; nightmares; restless sleep; shakiness; slurred speech; or unusual tiredness or weakness.
- If symptoms of low blood sugar occur, eat glucose tablets or gel, corn syrup, honey, or sugar cubes; or drink fruit juice, non-diet soft drinks, or sugar dissolved in water. Also, check your blood for low blood sugar. Glucagon is used in emergency situations when severe symptoms such as seizures (convulsions) or unconsciousness occur. Have a glucagon kit available, along with a syringe or needle, and know how to use it. Members of your family also should know how to use it.
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.
- Symptoms of high blood sugar include blurred vision; drowsiness; dry mouth; flushed, dry skin; fruit-like breath odor; increased urination (frequency and amount); ketones in the urine; loss of appetite; sleepiness; stomachache, nausea, or vomiting; tiredness; troubled breathing (rapid and deep); unconsciousness; or unusual thirst.
- If the symptoms of high blood sugar occur, check your blood sugar level and call your doctor for instructions.