NEUROCOBAL

Indications

• Vitamin B12 deficiency
• Megaloblastic anemia
• Peripheral neuropathy
• Neuropathic pain
• Multiple sclerosis

Dosage

Children: For paediatric patients, refer to the BNF for Children for appropriate dosing guidelines.

Adults: The typical adult dosage for methylcobalamin is 500 micrograms to 1,000 micrograms administered intramuscularly or subcutaneously, usually once daily for the initial treatment, followed by maintenance doses as needed.

Mechanism of action

Methylcobalamin serves as a cofactor for the enzyme methionine synthase, which catalyzes the conversion of homocysteine to methionine. This reaction is crucial in the synthesis of S-adenosylmethionine (SAMe), an important methyl donor in numerous methylation reactions within the body. Methylcobalamin also plays a role in myelin formation and the maintenance of nerve cells.

Pharmacodynamics

Methylcobalamin exhibits neuroprotective effects, promoting nerve regeneration and repair in peripheral neuropathy. It is believed to enhance nerve conduction and improve neurological function. The physiological effects are primarily attributed to its role in methylation processes and the synthesis of neurotransmitters.

Pharmacokinetics

Methylcobalamin is water-soluble and is absorbed in the intestine. The bioavailability can be affected by gastrointestinal health, and intrinsic factor is not required for its absorption. It is distributed throughout the body, with high concentrations in the liver, kidneys, and brain. The elimination half-life of methylcobalamin is approximately 6 hours, and it is excreted primarily in the urine.

Adverse effects

• Nausea
• Diarrhea
• Headache
• Dizziness
• Anxiety
• Rash
• Pruritus

Precautions

• Monitor patients with Leber's disease due to potential optic nerve damage.
• Caution in patients with allergies to cobalt or vitamin B12.
• Use with caution in patients with renal impairment.

Pregnancy

Methylcobalamin is classified as a category A drug. It is generally considered safe during pregnancy, but consultation with a healthcare provider is recommended.

Breast-feeding

Methylcobalamin is excreted in breast milk. It is generally considered safe during breastfeeding, but consultation with a healthcare provider is recommended.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Tablets
• Injections
• Sublingual tablets
• Oral solutions