Galantamine: a review of its use in Alzheimer's disease

Abstract

Currently, acetylcholinesterase (AChE) inhibitors are the most promising class of drugs for the treatment of Alzheimer's disease (AD). Galantamine is a reversible, competitive, tertiary alkaloid AChE inhibitor. The drug is selective for AChE rather than butyrylcholinesterase. In addition to inhibition of AChE galantamine interacts allosterically with nicotinic acetylcholine receptors to potentiate the action of agonists at these receptors. Recipients of galantamine 16 or 24 mg/day achieved significant improvements in cognitive and global symptoms relative to placebo recipients in large (n = 285 to 978 patients with mild to moderate AD) well-designed trials of 3 to 6 months' duration. Galantamine also improved activities of daily living in these patients and significantly reduced the requirement for caregiver assistance with activities of daily living. Moreover, galantamine recipients achieved significantly better outcomes on behavioural symptoms than placebo recipients. In a long term study (12 months), galantamine 24 mg/day slowed the progression of symptoms of the disease and maintained cognitive function and activities of daily living in patients with mild to moderate AD. Galantamine was generally well tolerated with the majority of adverse events being mild to moderate in intensity and transient. Predictably, adverse events were cholinergic in nature and generally related to the gastrointestinal system. These effects were reduced in patients receiving the recommended dose escalation regimen. Galantamine had no clinically relevant effects on vital signs, haematological or biochemical laboratory parameters and, importantly, there were no reports of hepatotoxicity. The incidence of serious adverse events was similar between galantamine (8 to 32 mg/day) and placebo groups (6 to 16% of patients across all treatment groups).

Conclusions: Galantamine is an effective well tolerated symptomatic treatment for AD which improves cognition, function and activities of daily living in the short term (up to 6 months) in patients with mild to moderate AD. In addition, it delays the development of behavioural disturbances and psychiatric symptoms, and reduces caregiver burden (as measured by caregiver time). In the long term (up to 1 year), galantamine maintains cognition and activities of daily living. Adverse events associated with galantamine are mainly cholinergic, usually mild to moderate in intensity and transient. Galantamine has been evaluated in several large well-designed studies and, given the relative lack of established treatment options, it may be considered as one of the first-line pharmacological treatments in patients with mild to moderate AD.