A fixed-dose combination (FDC) of Gabapentin, a gamma-aminobutyric acid (GABA) analogue anticonvulsant, and Methylcobalamin, the active form of Vitamin B12. This combination is primarily used in the Indian market for the management of neuropathic pain, particularly diabetic peripheral neuropathy, and for addressing symptoms of peripheral neuropathy like numbness and tingling. Gabapentin modulates calcium channels to reduce neuronal excitability, while Methylcobalamin supports nerve regeneration and myelin synthesis.
Adult: Typically 1 tablet (Gabapentin 100mg + Methylcobalamin 500mcg) two to three times daily. Gabapentin dose is usually titrated: Start with 100mg TDS, may be increased based on response and tolerability to 300mg TDS. The maximum recommended dose of Gabapentin for neuropathic pain is 1800-3600 mg/day in divided doses, but this FDC is a low-dose formulation.
Note: Take with or without food. Food does not significantly affect Gabapentin absorption but may improve GI tolerance. Swallow whole with a glass of water. Do not crush or chew. Maintain consistent timing of doses.
Gabapentin binds with high affinity to the α2-δ subunit of voltage-gated calcium channels in the central nervous system. This binding inhibits the release of several excitatory neurotransmitters (e.g., glutamate, substance P, norepinephrine) involved in pain signaling. It does not interact with GABA receptors directly. Methylcobalamin acts as a cofactor for methionine synthase, essential for myelin synthesis and nerve regeneration, and for L-methylmalonyl-CoA mutase, involved in fatty acid metabolism crucial for neuronal integrity.
Pregnancy: Gabapentin: Pregnancy Category C (US FDA). Limited human data, potential risk. Use only if benefit outweighs risk. Methylcobalamin: Category A (considered safe). However, the combination should be used in pregnancy only if clearly needed.
Driving: May impair alertness and motor coordination. Patients should not drive or operate heavy machinery until they know how the medication affects them.
| Opioids (e.g., Morphine, Oxycodone) | Increased risk of severe sedation, respiratory depression, and death. | Major |
| Antacids (Aluminum, Magnesium hydroxide) | Reduces Gabapentin bioavailability by up to 20%. Administer Gabapentin at least 2 hours after antacid. | Moderate |
| Alcohol / CNS Depressants | Additive CNS depression (drowsiness, dizziness). | Major |
| Levodopa | Methylcobalamin may reduce Levodopa efficacy in Parkinson's disease. | Moderate |
| Chloramphenicol | May decrease the hematopoietic response to Methylcobalamin. | Moderate |
Same composition (Gabapentin (100mg) + Methylcobalamin (500mcg)), different brands: