Memantine

Common use

Memantine is used to treat moderate to severe dementia in people with Alzheimer’s disease (AD). Memantine works to help relieve symptoms of AD by blocking NMDA receptors that, when persistently activated by glutamate, cause AD symptoms. While this mechanism helps to manage symptoms, memantine has not been shown to prevent or slow the underlying nerve degeneration associated with AD. Memantine belongs to the drug class called N-methyl-D-aspartate (NMDA) receptor antagonists.

Dosage and direction

Initial dose: 5 mg once daily. Titration: Increase by 5 mg increments once a week. Maximum dosage: 10 mg twice daily. Memantine tablets or extended-release capsules may be taken with food or without food.

Precautions

Tell your healthcare provider about all your medical conditions, including if you: have a seizure disorder; have cataracts; have liver or kidney disease; have a bladder or kidney infection; have problems passing urine; are pregnant or intending to become pregnant; are breastfeeding.
It is not known if memantine is safe and effective in children. It is not known if memantine will harm an unborn baby. It is not known if memantine passes into your breast milk. Talk to your doctor about the best way to feed your baby during treatment.

Contraindications

Before taking memantine, tell your doctor if you are allergic to memantine, Namenda, or any inactive ingredients in the tablets or capsules.
Memantine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Possible side effect

The most common side effects of memantine include: dizziness; headache; confusion; constipation.

Drug interaction

Tell your doctor if you take: other NMDA antagonists such as amantadine, ketamine, and dextromethorphan; medicines that make your urine alkaline, such as carbonic anhydrase inhibitors and sodium bicarbonate.

Missed dose

If you forget to take one dose of memantine, do not double up on the next dose. You should take only the next dose as scheduled. If you have forgotten to take memantine for several days, you should not take the next dose until you talk to your doctor.

Overdose

If you take too much memantine, call your doctor or go to the nearest hospital emergency room.

Storage

Store memantine tablets and capsules at room temperature between 59°F to 77°F (15°C to 30°C).