galantamine

Galantamine is a plant-derived alkaloid used as a prescription medication for symptomatic treatment of mild to moderate Alzheimer's disease. It acts as a reversible inhibitor of acetylcholinesterase, increasing acetylcholine levels in the brain, and also serves as an allosteric positive modulator of nicotinic acetylcholine receptors, which can enhance cholinergic neurotransmission beyond enzyme inhibition.

Galantamine is typically administered orally in immediate-release tablets or extended-release formulations. In the immediate-release form, dosing commonly starts at 4 mg twice daily for several weeks and may be increased to 8 mg twice daily and then to 12 mg twice daily, depending on tolerability. In extended-release form, dosing starts at 8 mg once daily, with gradual increases to 16 mg and then 24 mg once daily. Maximum daily dose is generally 24 mg, depending on formulation and local guidelines. It is metabolized in the liver primarily by CYP2D6 and CYP3A4 and is excreted in urine and bile.

Common adverse effects include nausea, vomiting, diarrhea, loss of appetite, dizziness, and bradycardia; these cholinergic side effects are usually dose-related and may lead to discontinuation in some patients. Caution is advised in individuals with cardiac conduction disorders, asthma or COPD, and in those taking other cholinesterase inhibitors or anticholinergic medicines. Dose adjustments may be required in hepatic or renal impairment.

Galantamine is marketed under brand names such as Razadyne in the United States and Reminyl or Galantamine ER in other markets. It is approved in many countries for symptomatic treatment of mild-to-moderate Alzheimer's disease and is not a disease-modifying therapy.