Amantadine - side effects: do they wear off?

I have been prescribed Amantadine for moderate fatigue and low energy by my Neurologist. I have taken 100mg a day, although was prescribed 2 x 100mg per day. It has affected me getting to sleep, being able to concentrate at work (mind flitting from one thing to the next, poor concentration span) and then once I had an irregular heartbeat. This scared me and I have stopped taking it.

Do these side effects wear off, and, if so, after how long?

Can you take a lower dose?

Interested in different experiences with Amantadine.


I have been taking Amantadine since about March [2 x 100 mg daily]. I did [still do] get dizziness/light-headed, but just thought it was another MS symptom.

However, just lately, I have been feeling very dizzy with headaches. Sleep is very disturbed too and concentration seem to be getting worse. It wasn’t until I saw your post that I made any connection. Having said that, I do suffer with horrendous fatigue and amantadine has seemed to help. So I suppose it’s a question of which of the 2 evils is worse.

I am now wondering if I should decrease it to 1 x 100 mg daily?? Will go and see G.P.

Sorry - probably hasn’t answered your question. It’s just a question of finding the dose that works best for you.

Hope you manage to sort it.

Jody x

Hi Lou. I have been on Amantadine for about two years. I take 100mg in the morning and it definitely helps with fatigue. I have never had any side effects.



I couldn’t sleep when I took this, I persevered for a little while, and tried a reduced dose, the neuro said not to take them after 4pm, to no avail, so gave up. They didn’t really make any difference to the fatigue either.