What brand names are available for rosiglitazone/metformin?
Avandamet
Is rosiglitazone/metformin available as a generic drug?
Yes
Do I need a prescription for rosiglitazone/metformin?
Yes
What are the uses for rosiglitazone/metformin?
Avandamet is used with diet and exercise to improve blood
glucose control in adult patients with type 2 diabetes.
What are the side effects of rosiglitazone/metformin?
The most common side effects include
- nausea,
- vomiting,
- diarrhea, and
- upset stomach.
Taking Avandamet with food may help lessen some of
these side effects. Other commonly reported side effects include
- headache,
- cold-like symptoms,
- joint aches, and
- dizziness.
Rare but serious side effects include new or
- worsening
heart failure, - heart
attack, - edema or swelling (water retention),
- weight gain,
- liver problems,
- macula
edema (a diabetic eye disease with swelling in the back of the eye), -
bone
fractures, - low red blood cell count,
- low blood glucose (hypoglycemia), and
-
ovulation (increasing the chance of
pregnancy).
Metformin can cause a rare but serious condition known as lactic acidosis, a
build-up of acid in the blood. Lactic acidosis can cause death and requires
immediate treatment. Symptoms of lactic acidosis include
- tiredness,
- weakness,
- unusual
muscle pain, - pain in the stomach,
- difficulty breathing,
- dizziness, and
- slow or irregular heartbeat.
Patients suspected of have signs or symptoms of
lactic acidosis must seek emergency medical help.
What is the dosage for rosiglitazone/metformin?
The dosage of Avandamet should be individualized based on patient
response and tolerability. It is generally given in divided doses with meals.
For patients inadequately controlled on diet and exercise
- Generally, the recommended starting dose of Avandamet is 2/500 mg
administered once or twice daily. - A starting dose of 2/500 mg twice daily may be considered for patients with
HbA1c >11% or fasting plasma glucose (FPG) >270 mg//dL. - If patients are not adequately controlled after 4 weeks of treatment the
dosage may be increased in increments of 2/500 mg as necessary. - The maximum daily dose of Avandamet is 8/2,000 mg.
For patients inadequately controlled on rosiglitazone or metformin
monotherapy
- The selection of the dose of Avandamet must be based on the patient’s current
doses of rosiglitazone and/or metformin. - To switch to Avandamet for patients currently treated with metformin
- The usual starting dose of Avandamet is 4 mg rosiglitazone and base the
metformin dose on the current dose of metformin. - To switch to Avandamet for patients currently treated with rosiglitazone
- The usual starting dose of Avandamet is 1,000 mg metformin and the
corresponding dose of rosiglitazone that the patient is taking.
The safety and efficacy of Avandamet has not been established in pediatric
patients. Therefore, use of Avandamet in this patient population is not
recommended.
Metformin-containing drugs may be safely used in patients with mild to moderate renal impairment. Renal function should be assessed before starting treatment and at least yearly.
Metformin should not be used by patients with an estimated glomerular filtration rate (eGFR) below 30 mL/minute/1.73 m2 and starting metformin in patients with an eGFR between 30-45 mL/minute/1.73 m2 is not recommended.
Metformin should be stopped at the time of or before administering iodinated contrast in patients with an eGFR between 30 and 60 mL/minute/1.73 m2; in patients with a history of liver disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Kidney function should be evaluated 48 hours after receiving contrast and metformin may be restarted if kidney function is stable.
Which drugs or supplements interact with rosiglitazone/metformin?
Rosiglitazone is extensively metabolized or broken down by a group of liver
enzymes known as CYP2C8. Gemfibrozil (Lopid), a known inhibitor of CYP2C8 may
increase blood levels of rosiglitazone and consequently increase the risk of
side effects. Concomitant use of agents that also inhibit CYP2C8 requires a
reduction in the dose of rosiglitazone.
Rifampin (Rimactane or Rifadin), a known inducer of CYP2C8, increases the
breakdown of rosiglitazone. Therefore, concomitant use of agents that induce
CYP2C8 may decrease the effectiveness of rosiglitazone.
Drugs which cause blood glucose levels to increase may diminish the
effectiveness of Avandamet therapy. These drugs include
- thiazides,
- other
diuretics, - corticosteroids,
- phenothiazines,
- thyroid medications,
- estrogens,
- birth control pills,
- phenytoin (Dilantin),
- nicotinic acid,
- sympathomimetics,
-
calcium channel blockers
(CCBs), and - isoniazid (Nydrazid).
Is rosiglitazone/metformin safe to take if I’m pregnant or breastfeeding?
- Avandamet has not been adequately evaluated in
pregnant women. Due
to the lack of conclusive safety data, Avandamet should be used in pregnancy
only if the potential benefit justifies the potential risk to the fetus.
Avandamet is classified as FDA pregnancy risk category C. - It is not known if Avandamet is excreted in breast milk. Due
to the lack of safety data, Avandamet is not recommended for use in
nursing
mothers.
What else should I know about rosiglitazone/metformin?
What preparations of rosiglitazone/metformin are available?
Oral tablets containing Avandamet: 2/500, 4/500, 2/1,000, and
4/1,000 mg.
How should I keep rosiglitazone/metformin stored?
- Tablets should be stored at room temperature, between 15 C and 30 C (59
F and 86 F). - Tablets should be dispensed and stored in an air-tight,
light-resistant container.