API

Metformin (1000mg) + Methylcobalamin (750mcg)

Drug classification

Antidiabetic combination; biguanide (metformin) and vitamin B12 analog (methylcobalamin) subclass.

Dosage form

Film-coated, sustained-release oral tablet.

API strength per dosage

Dose

Standard adult dosing for Rejumet 1000 Tablet SR is typically one tablet once daily with meals. Dose adjustments may be needed in renal impairment; metformin is contraindicated in severe renal dysfunction (eGFR <30 mL/min/1.73m²). Use in children is not established. Caution is advised in hepatic impairment due to increased risk of lactic acidosis.

Mechanism of action

Metformin decreases hepatic glucose production and increases insulin sensitivity by activating AMP-activated protein kinase (AMPK). Methylcobalamin, an active form of vitamin B12, serves as a cofactor for methionine synthase, supporting neuronal function and red blood cell formation. Together, they improve glycemic control and address potential B12 deficiency.

Indications

Treatment of Type 2 diabetes mellitus

Side effects

Nausea Taste change Loss of appetite Diarrhea Stomach pain

Pregnancy category

Metformin is generally considered safe in pregnancy when clearly needed; methylcobalamin is a form of vitamin B12 and is not associated with fetal risk.

Precautions

Assess renal function before and during therapy, monitor for lactic acidosis symptoms, avoid in severe renal or hepatic impairment, monitor vitamin B12 levels with long-term use, use caution in elderly, assess for gastrointestinal intolerance, avoid excessive alcohol intake, monitor blood glucose regularly, discontinue before iodinated contrast procedures.

Contraindications

Hypersensitivity to metformin or methylcobalamin, severe renal impairment, acute or chronic metabolic acidosis (including diabetic ketoacidosis), severe hepatic impairment, alcoholism, conditions predisposing to hypoxemia, recent radiographic contrast administration.