PANFOR SR-1000 TABLETS

Indications

• Type 2 diabetes mellitus
• Polycystic ovary syndrome (off-label use)
• Prevention of type 2 diabetes in high-risk patients (off-label use)

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

Metformin primarily acts by inhibiting hepatic glucose production, particularly in the liver, and enhancing insulin sensitivity in peripheral tissues, particularly muscle. It activates AMP-activated protein kinase (AMPK), which plays a crucial role in energy homeostasis and glucose metabolism. This activation leads to a decrease in gluconeogenesis and an increase in glucose uptake by tissues, thus lowering blood sugar levels.

Pharmacodynamics

Metformin does not cause insulin secretion from the pancreas and, therefore, does not typically cause hypoglycemia. Its effects on glucose metabolism result in improved glycemic control. Metformin may also promote weight loss or weight neutrality, which is an advantage for many patients with type 2 diabetes who are overweight or obese.

Pharmacokinetics

Metformin is absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 2-3 hours after oral administration. It is not extensively metabolized and is primarily excreted unchanged in the urine. The elimination half-life is about 4-8 hours, and renal function significantly affects its clearance. Dosage adjustments may be necessary in patients with renal impairment to avoid accumulation and potential lactic acidosis.

Contra-indications

• Severe renal impairment
• Acute or chronic metabolic acidosis, including diabetic ketoacidosis
• Hypersensitivity to metformin or any excipients

Adverse effects

• Gastrointestinal disturbances (nausea, vomiting, diarrhea)
• Lactic acidosis (rare but serious)
• Vitamin B12 deficiency
• Hypoglycemia (when used with other antidiabetic agents)

Interactions

• Alcohol increases the risk of lactic acidosis
• Certain diuretics may enhance the effect of metformin
• Cationic drugs that are eliminated by renal tubular secretion may interact with metformin

Precautions

• Monitor renal function regularly
• Caution in patients with liver impairment
• Should be temporarily discontinued prior to radiologic studies involving iodinated contrast media

Pregnancy

Metformin may be used in pregnancy if the benefits outweigh the risks, especially in women with pre-existing diabetes.

Breast-feeding

Metformin is excreted in breast milk, but is generally considered safe for use during breastfeeding.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Tablets (regular and extended-release)
• Oral solution