Metformin

Type 2 Diabetes: The usual initial dose is 500mg twice a day or 850mg once a day. Your healthcare provider may gradually increase your dose until your blood sugar is better controlled (the maximum dose is 2000mg daily).

• Those who have severe kidney disease or diabetic ketoacidosis.
• If you are about to receive an iodinated contrast injection for scans, as this can interact with Metformin.
• Patients with severe liver disease.

• Metformin is generally taken with meals to help lessen stomach adverse effects.
• Monitor your blood sugar levels regularly.
• Do not suddenly stop taking Metformin without talking to your healthcare provider.
• Stay hydrated and avoid excessive consumption of alcohol.

• Nausea, stomach upset, and diarrhea (usually decrease over time)
• Metallic taste in the mouth

• Rarely, lactic acidosis can occur, which is a severe metabolic condition.
• Look out for sudden stomach pains, rapid breathing, slow or irregular heartbeat, or severe nausea.

• Lactic Acidosis: This is a rare but serious complication. Lactic acidosis is a buildup of lactic acid in the bloodstream and can be life-threatening. The risk may be higher in those with renal impairment, liver disease, or conditions associated with hypoxia.
• Kidney Function: Metformin is cleared by the kidneys. In individuals with reduced kidney function, the drug can accumulate, leading to an increased risk of side effects, including lactic acidosis. Regular monitoring of kidney function is recommended.
• Hypoglycemia: While metformin on its own is not usually associated with significant hypoglycemia, the risk can increase when combined with other antidiabetic agents, like sulfonylureas or insulin.
• Radiologic Studies: Patients may need to stop taking metformin temporarily if they undergo certain radiologic tests that require the administration of iodinated contrast materials, as there's a risk of acute kidney injury.
• Surgery: Metformin might be discontinued temporarily around the time of major surgery due to concerns about renal function.
• Altered Drug Levels with Liver Disease: Liver disease can affect the pharmacokinetics of metformin. It's crucial to use it with caution and monitor patients with liver impairment closely.
• Heart Failure: While metformin can be used in some patients with heart failure, it should be used with caution, and patients should be closely monitored for signs of worsening heart failure.
• Gastrointestinal Side Effects: While not a "warning" in the strict sense, a significant number of patients experience gastrointestinal side effects like nausea, vomiting, diarrhea, abdominal discomfort, or a metallic taste. These side effects might decrease by taking metformin with meals or using the extended-release formulation.

Cationic Drugs: Drugs that are eliminated by renal tubular secretion (like cimetidine, digoxin, amiloride, morphine, procainamide, quinidine, quinine, ranitidine, triamterene, trimethoprim, or vancomycin) may compete with metformin for elimination, leading to increased levels of both drugs.

Insulin or Insulin Secretagogues (like sulfonylureas): When metformin is combined with these drugs, the risk of hypoglycemia increases.

Beta-blockers: These drugs can blunt the symptoms of hypoglycemia, which might decrease the patient's ability to recognize low blood sugar events if they are on combination therapy with drugs that increase the risk of hypoglycemia.

Topiramate: This antiepileptic drug can potentiate metformin's effects on lactate metabolism, theoretically increasing the risk of lactic acidosis.

Thiazide Diuretics: These can increase blood sugar levels, potentially counteracting the blood sugar-lowering effect of metformin.

Glucocorticoids: Like thiazide diuretics, glucocorticoids (often called "steroids") can raise blood sugar levels.

Nifedipine: This calcium channel blocker can increase the absorption of metformin, leading to higher plasma levels.

Phenytoin: It may enhance the release of metformin from the gastrointestinal tract, potentially altering metformin's effects.

• Glipizide
• Gliclazide
• Canagliflozin
• Liraglutide
• Sitagliptin