A fixed-dose combination of three essential B vitamins used primarily for the treatment and prevention of neuropathies, nutritional deficiencies, and certain metabolic disorders. Methylcobalamin is the active, coenzyme form of Vitamin B12, crucial for nerve health and hematopoiesis. Pyridoxine (B6) is a cofactor in amino acid metabolism and neurotransmitter synthesis. Nicotinamide (a form of Vitamin B3) is essential for NAD+ synthesis, cellular energy production, and DNA repair. This combination is extensively prescribed in India for diabetic peripheral neuropathy, vitamin B deficiency syndromes, and as supportive therapy in various neurological conditions.
Adult: One tablet/capsule once daily, or as directed by the physician. Often prescribed as 1 OD for 4-8 weeks, then 1 on alternate days for maintenance in chronic neuropathies.
Note: Administer orally with or without food. Preferably taken in the morning to align with circadian energy metabolism. Swallow whole with a glass of water. Do not crush or chew unless specified (some brands are chewable).
The combination acts synergistically to correct deficiencies, support nerve myelination, modulate pain pathways, and improve neuronal metabolism. Methylcobalamin is a cofactor for methionine synthase (converting homocysteine to methionine) and L-methylmalonyl-CoA mutase. This supports myelin synthesis, nucleic acid production, and reduces neurotoxic homocysteine. Pyridoxine, as PLP, is a cofactor for over 140 enzymes, including those involved in neurotransmitter synthesis (GABA, serotonin, dopamine), heme synthesis, and homocysteine metabolism (via cystathionine beta-synthase). Nicotinamide is a precursor for NAD+ and NADP+, critical coenzymes in cellular respiration (glycolysis, TCA cycle, oxidative phosphorylation), DNA repair via PARP enzymes, and cellular antioxidant defense.
Pregnancy: Category A (Indian categorization). Vitamins B12, B6, and B3 are considered safe in pregnancy at recommended dietary allowances. This high-dose pharmacological combination should be used only if clearly needed and under medical supervision. Methylcobalamin and Pyridoxine are often used for pregnancy-related neuropathies and hyperemesis.
Driving: No known effects. However, if dizziness occurs as a rare side effect, caution is advised.
| Levodopa (without Carbidopa) | Pyridoxine increases the peripheral decarboxylation of Levodopa, reducing its availability to the CNS and diminishing its anti-parkinsonian effect. | Major |
| Chloramphenicol | May antagonize the hematopoietic response to Methylcobalamin in treating anemia. | Moderate |
| Phenytoin / Phenobarbital | May reduce serum levels of these anticonvulsants. Pyridoxine may also enhance their metabolism. | Moderate |
| Isoniazid, Cycloserine, Penicillamine | These drugs are Pyridoxine antagonists and can increase the requirement for B6, potentially leading to deficiency if not supplemented. | Moderate |
| Proton Pump Inhibitors (Omeprazole), H2 Blockers (Ranitidine), Metformin | Long-term use can reduce absorption of dietary Vitamin B12. Methylcobalamin at this high dose is often used to overcome this. | Minor (therapeutic combination often used to counter this) |
| 5-Fluorouracil (5-FU) | Methylcobalamin may reduce the anti-neoplastic activity of 5-FU. | Major (contraindicated in cancer patients on 5-FU) |
Same composition (Methylcobalamin (1000mcg) + Vitamin B6 (Pyridoxine) (100mg) + Nicotinamide (100mg)), different brands: