Metformin
Generic Name: Metformin
Brand Name: Glucophage
Indications
Glucophage (metformin hydrochloride tablets) is indicated as an adjunct to diet and exercise to improve glycemic control in adults and children with type 2 diabetes mellitus.
Dosage and Administration
Glucophage tablets are available in strengths of 500mg, 800mg and 1000mg and Glucophage XR (extended-release) tablets are available in the strengths of 500mg and 700mg.
Normal Dosage: There is no fixed dosage regimen for the management of hyperglycemia in patients with type 2 diabetes with Glucophage or Glucophage XR or any other pharmacologic agent. Dosage of Glucophage or Glucophage XR must be individualized on the basis of both effectiveness and tolerance, while not exceeding the maximum recommended daily doses. The maximum recommended daily dose of Glucophage is 2550 mg in adults and 2000 mg in pediatric patients (10-16 years of age); the maximum recommended daily dose of Glucophage XR in adults is 2000 mg.
Glucophage should be given in divided doses with meals while Glucophage XR should generally be given once daily with the evening meal. Glucophage or Glucophage XR should be started at a low dose, with gradual dose escalation, both to reduce gastrointestinal side effects and to permit identification of the minimum dose required for adequate glycemic control of the patient.
Overdose: An overdose is likely to cause lactic acidosis. Symptoms of lactic acidosis include a feeling of general discomfort or sickness, weakness, unusual drowsiness, dizziness or lightheadedness, and the sudden development of a slow or irregular heartbeat.
Drug description
Metformin hydrochloride (N,N-dimethylimidodicarbonimidic diamide hydrochloride) is not chemically or pharmacologically related to any other classes of oral antihyperglycemic agents. The structural formula is as shown:
Metformin hydrochloride is a white to off-white crystalline compound with a molecular formula of C4H11N5 • HCl and a molecular weight of 165.63. Metformin hydrochloride is freely soluble in water and is practically insoluble in acetone, ether, and chloroform. The pKa of metformin is 12.4. The pH of a 1% aqueous solution of metformin hydrochloride is 6.68.
Side effects
The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
- Disturbances of the gut such as nausea, vomiting, diarrhoea or abdominal pain.
- Loss of appetite.
- Metallic taste.
- Elevated levels of lactic acid in the blood (lactic acidosis).
- Decreased absorption of vitamin B12 during long-term use.
- Skin reactions such as rash, itching or flushing.
Precautions
- Avoid excessive alcohol intake. They may increase the risk of lactic acidosis and hypoglycemia.
- Tell your doctor that you are taking this medication if you become ill, if you have a heart attack; if you have a stroke; if you develop congestive heart failure; if you experience diarrhea, fever, or dehydration from any cause; or if you decrease the amount of food or liquid in your normal diet.
- Metfomin is in the FDA pregnancy category B. This means that it is unlikely to harm an unborn baby .Do not take without first talking to your doctor if you are pregnant.
Drug Interactions
Before taking Metformin, tell your doctor if you are taking any of the following medications:
- digoxin (Lanoxin, Lanoxicaps)
- procainamide (Pronestyl)
- quinidine (Cardioquin, others)
- cimetidine (Tagamet, Tagamet HB) or ranitidine (Zantac, Zantac 75)
- morphine (Astramorph, MS Contin, Roxanol, and others)
- trimethoprim (Proloprim, Trimpex, Septra, Bactrim)
- phenytoin (Dilantin)
- isoniazid (Nydrazid)
- nicotinic acid or niacin (Nicobid, Nicolar, others)
