Memantine hydrochloride

How it works

It provides voltage-dependent, non-competitive blockade of the NMDA glutamate receptor, attenuating pathological glutamatergic activity while preserving physiological signalling.

Prescribing in practice

• The dose must be reduced in moderate to severe renal impairment because elimination depends on renal function and is reduced when urine is alkaline.
• Use with caution in epilepsy and in patients with a history of seizures, and review concurrent NMDA-acting drugs such as ketamine and amantadine.
• Titrate the dose upward gradually to improve tolerability.

Monitoring

Monitor renal function, cognitive and functional response and tolerability including dizziness, confusion and headache.

Counselling the patient

• It can be taken with or without food, ideally at a consistent time each day.
• Report dizziness, confusion or new seizures.
• Carers should continue regular review of benefit and overall function.

Evidence & guidelines

NICE recommends memantine as an option for managing moderate to severe Alzheimer's disease.