Memantine

Sounds like 'MEM-an-teen'

Easy-to-read medicine information about memantine – what it is, how to take memantine safely and possible side effects.

Type of medicine Also called
  • Medicines for dementia
  • Ebixa®

What is memantine?

Memantine is used to treat dementia associated with moderate to severe  Alzheimer's disease. It helps to ease symptoms such as memory loss, but does not cure dementia. Memantine works by reducing the amount of a chemical in the brain, called glutamate. It is thought that this may help to slow down the damage to brain cells affected by Alzheimer's disease. Read more about medicines for dementia.

In New Zealand memantine is available as tablets (10 mg) and is currently not funded.

Dose

  • Your doctor will start you on a low dose and increase your dose slowly over a few weeks. This allows your body to get used to the medicine and reduces side effects.
  • The usual starting dose of memantine is 5 mg once a day.
  • Thereafter, your doctor will increase your dose by 5 mg every week, to a maximum of 20 mg once a day.
  • If you are unsure about your dose, talk to your pharmacist. The following is a guide.
Dates Memantine dose
Date: ____________to _________

(Week 1)
  • Take half a tablet (5 mg) once a day
Date: ____________to _________

(Week 2)
  • Take one tablet (10 mg) once a day
Date: ____________to _________

(Week 3)
  • Take one and a half tablets (15 mg) once a day
Date: ____________to _________

(Week 4)
  • Take two tablets (20 mg) once a day
  • Always take your memantine exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much memantine to take, how often to take it, and any special instructions.
  • You will need to see your doctor regularly to check your response to treatment, if the dose is right, and if this medicine is right for you. 

How to take memantine?

  • Take memantine once a day, with or without food. 
  • You can take memantine at whatever time of day suits you best, but try to take your doses at the same time of day each day. 
  • Swallow your tablets whole with a glass of water – do not chew them.
  • Keep taking memantine every day. It may take a while before you notice the full benefits of the medication.
  • It is important that you take memantine every day. If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.

Precautions – before starting memantine

  • Do you have problems with your liver or kidneys?
  • Do you have epilepsy?
  • Are you taking any other medicines, including medicines you can buy without a prescription, such as herbal and complementary medicines?

If so, it’s important that you tell your doctor or pharmacist before you start memantine. Sometimes a medicine isn’t suitable for a person with certain conditions or it can only be used with extra care.

Possible side effects

Like all medicines, memantine can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Nausea (feeling sick) 
  • Try taking memantine with food or a snack and make sure you are drinking enough water.
  • Tell your doctor if troublesome; they may recommend a lower dose.
  • Constipation
  • Make sure you drink plenty of water, and have lots of fibre in your diet such as fresh fruit and vegetables.
  • Tell your doctor if troublesome
  • Loss of appetite
  • Feeling anxious
  • Headache
  • These are quite common when you first start taking memantine and usually go away with time.
  • Tell your doctor if troublesome. 
  • Tiredness
  • Dizziness,
  • Feeling faint
  • Try getting up or moving slowly.
  • If you begin to feel faint, sit or lie down until the feeling passes.
  • Avoid driving until you know how this medicine affects you.
    Do not drink alcohol.
  • Tell your doctor if this continues.
  • Signs of an allergic reaction such as itchy skin, rash, swelling of the face, lips, mouth or throat, difficulty breathing.
  • Tell your doctor immediately or ring HealthLine 0800 611 116.

Learn more

The following link has more information on memantine.

Ebixa Medsafe Consumer Information Sheet

References

  1. The pharmacological management of Alzheimer’s disease – the place of donepezil BPAC, NZ, 2010
  2. Antipsychotics in dementia – best practice guide BPAC, NZ
  3. Managing patients with dementia – what is the role of antipsychotics? BPAC, NZ, 2013
  4. Memantine hydrochloride New Zealand Formulary
Credits: Sandra Ponen, pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 29 Apr 2019