Avandamet Side Effects

Generic Name: metformin / rosiglitazone

Note: This page contains information about the side effects of metformin / rosiglitazone. Some of the dosage forms included on this document may not apply to the brand name Avandamet.

Not all side effects for Avandamet may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to metformin / rosiglitazone: oral tablet

In addition to its needed effects, some unwanted effects may be caused by metformin / rosiglitazone. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking metformin / rosiglitazone:

More common
  • Pale skin
  • troubled breathing with exertion
  • unusual bleeding or bruising
  • unusual tiredness or weakness
Less common
  • Anxiety
  • blurred vision
  • chest pain or discomfort
  • chills
  • cold sweats
  • coma
  • confusion
  • cool, pale skin
  • depression
  • dilated neck veins
  • dizziness
  • extreme fatigue
  • fast heartbeat
  • headache
  • increased hunger
  • irregular breathing
  • irregular heartbeat
  • nausea
  • nightmares
  • seizures
  • shakiness
  • slurred speech
  • swelling of the face, fingers, feet, or lower legs
  • weight gain
  • Abdominal or stomach discomfort
  • decreased appetite
  • diarrhea
  • fast, shallow breathing
  • general feeling of discomfort
  • muscle pain or cramping
  • sleepiness
Incidence not known
  • Change in vision
  • dark urine
  • decreased urine output
  • hives or welts, itching, or skin rash
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • pain or discomfort in the arms, jaw, back, or neck
  • redness of the skin
  • stomach pain
  • sweating
  • vomiting

Some of the side effects that can occur with metformin / rosiglitazone may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Body aches or pain
  • cough, fever, sneezing, or sore throat
  • difficulty with breathing
  • ear congestion
  • loss of voice
  • pain or tenderness around the eyes and cheekbones
  • stuffy or runny nose
Less common
  • Back pain
  • cold or flu-like symptoms
  • difficulty with moving
  • pain in the joints

For Healthcare Professionals

Applies to metformin / rosiglitazone: oral tablet


Metformin-rosiglitazone has been generally well tolerated. Viral infection, injury, headache, back pain, fatigue, and arthralgia were reported slightly more frequently than placebo in clinical trials.


Lactic acidosis is a medical emergency requiring immediate evaluation and treatment. The case fatality rate may be as high as 50.3%. Patients taking metformin who present with even vague medical illnesses such as myalgia, malaise, somnolence, abdominal discomfort, and so forth, should be evaluated for a metabolic etiology like lactic acidosis.

Signs and symptoms of severe acidosis may include vomiting, abdominal pain, nausea, dyspnea, hypothermia, hypotension, and bradycardia.

Laboratory evaluation of metformin-induced lactic acidosis generally includes determination of the following: blood glucose concentration, lactic acid concentration, serum electrolytes, blood pH, metformin concentration, and exclusion of ketoacidosis.

If lactic acidosis is present, immediate institution of general supportive care is indicated. Prompt hemodialysis is also generally recommended in order to correct the acidosis and remove metformin. Hemodialysis often results in rapid improvement. Some investigators have suggested that dialysis with a bicarbonate-buffered dialysate may be particularly effective.

Metabolic side effects of metformin have included lactic acidosis, which is a potentially fatal metabolic complication of biguanide therapy. The incidence of lactic acidosis has been about 1.5 cases per 10,000 patient years. The incidence may be lower with current recommended doses and less frequent use in the elderly. The risk of lactic acidosis is particularly high in patients with underlying renal insufficiency. Cases of lactic acidosis occurring in patients with normal renal function have been rarely reported. Concomitant cardiovascular or liver disease, sepsis, and hypoxia may also increase the risk of lactic acidosis. Hypoglycemia occurs uncommonly in patients receiving metformin as monotherapy. Strenuous exercise, decreased caloric intake, general debilitation, adrenal insufficiency, pituitary insufficiency, and ethanol use may increase the risk of hypoglycemia. Metabolic side effects of rosiglitazone have included increases in total cholesterol, LDL, and HDL and decreases in free fatty acids. Dose related weight gain has been reported in patients treated with rosiglitazone alone and in combination with other hypoglycemic agents.


Cardiovascular side effects of rosiglitazone have included mild to moderate edema. Patients with congestive heart failure have experienced new or worsening edema. Compared to patients receiving placebo, patients with congestive heart failure (CHF) receiving rosiglitazone also experienced more cardiovascular deaths, more CHF worsening, more new or worsening dyspnea, more increases in CHF medication and cardiovascular hospitalization, more myocardial infarctions, and angina.

Healthy volunteers receiving rosiglitazone 8 mg once daily for 8 weeks experienced a statistically significant increase in median plasma volume compared to placebo. Patients with ongoing edema are more likely to have adverse events associated with edema if started on combination therapy with insulin and rosiglitazone.

Dose-related weight gain was seen with rosiglitazone alone and in combination with other hypoglycemic agents. The mechanism is unclear but probably involves a combination of fluid retention and fat accumulation.

In a 26-week study, edema was reported with higher frequency in the rosiglitazone plus insulin combination trials (insulin, 5.4%; and rosiglitazone with insulin 14.7%). Reports of new onset or exacerbation of congestive heart failure occurred at a rate of 1% for insulin alone, and 2% (4 mg) and 3% (8 mg) for insulin in combination with rosiglitazone.


Hematologic side effects have included decreases of previously normal levels of serum vitamin B12 to subnormal levels. Across all controlled clinical studies in adults, decreases in hemoglobin and hematocrit (mean decreases in individual studies of approximately 1.0 gram/dL and 3.3%, respectively) were observed for rosiglitazone maleate alone and in combination with other hypoglycemic agents.


Gastrointestinal side effects have included nausea, anorexia, metallic taste, diarrhea, dyspepsia, flatulence, and abdominal pain. Diarrhea has been reported by 12.7% of patients in clinical trials.


Respiratory side effects have included reports of upper respiratory tract infection in 16% and sinusitis in 6.2% of patients in clinical trials. Patients with congestive heart failure have experienced new or worsening dyspnea.


Hypersensitivity side effects have included rare postmarketing reports of urticaria and angioedema. Postmarketing experience has included rare reports of anaphylactic reactions.


Ocular side effects have included changes in accommodation and blurred vision. New onset or worsening (diabetic) macular edema with decreased visual acuity has been reported very rarely in postmarketing experience with rosiglitazone. In some cases, symptoms improved following discontinuation of rosiglitazone. Physicians should consider the possibility of macular edema if a patient reports decreased visual acuity.


Musculoskeletal side effects have included an increased incidence of bone fracture in female patients. The majority of the fractures in the women who received rosiglitazone occurred in the upper arm, hand, and foot. These sites of fracture are different from those usually associated with postmenopausal osteoporosis (e.g., hip or spine). No increase in fracture rates was observed in men treated with rosiglitazone.

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