Galantamine explained

What Galantamine is

Galantamine (Reminyl XL, also generic) is a Cholinesterase Inhibitor with a dual mechanism. It increases acetylcholine levels by inhibiting the enzyme acetylcholinesterase, and it also modulates nicotinic acetylcholine receptors, which may add a second mechanism for cognitive benefit.

Galantamine is licensed in the UK for mild to moderate Alzheimer's Disease, under NICE TA217.

Dosing

Galantamine is available as modified-release once-daily capsules and as an oral solution. The standard titration:

• Week 1 to 4: Galantamine 8 mg once daily;
• Week 5 onwards: 16 mg once daily;
• If tolerated and further benefit sought: 24 mg once daily.

Take with breakfast. Capsules should not be opened or crushed; the oral solution is available for those who cannot swallow capsules.

Galantamine is metabolised through the liver and partly excreted by the kidneys; dose adjustment is needed in moderate hepatic or renal impairment.

Effectiveness

Galantamine has similar efficacy to Donepezil and Rivastigmine across head-to-head and meta-analytic comparisons. About 60 per cent of people who tolerate Galantamine experience meaningful benefit in attention, memory and daily function over 6 to 12 months.

Side effects

The side effect profile is similar to other Cholinesterase Inhibitors. Most are gastrointestinal and transient:

• Nausea and vomiting in the first 1 to 2 weeks (often less than Donepezil);
• Diarrhoea;
• Reduced appetite and modest weight loss;
• Dizziness;
• Slowed heart rate;
• Rarely, fainting or falls.

Galantamine may have a slightly higher rate of mortality in patients with significant cardiovascular disease compared with Donepezil in some studies, although the absolute risk is small. Discuss with your prescriber if you have multiple cardiovascular conditions.

When Galantamine may be preferred

• When Donepezil has caused vivid dreams or insomnia;
• When once-daily morning dosing fits the routine better;
• When the dual nicotinic mechanism is considered theoretically helpful (mild evidence base);
• Personal preference and tolerability.

When to switch

If Galantamine is poorly tolerated, switching to Donepezil or to a Rivastigmine patch is reasonable. Switching is usually a direct cross-over with appropriate dose adjustment, under prescriber guidance.

Monitoring and review

A three-month review after reaching the target dose is standard, followed by 6- to 12-monthly reviews. The review assesses tolerability, response, pulse and blood pressure, and whether to continue, switch or add Memantine.

Before starting

The standard pre-prescribing checks for any Cholinesterase Inhibitor apply: Electrocardiogram, medication review, history of asthma or active peptic ulcer, history of seizures, kidney and liver function.