Introduction

This information is for people who have multiple sclerosis. It tells you about modafinil, a treatment used to help tiredness in multiple sclerosis. It is based on the best and most up-to-date research.

Does it work?

We don't know. Modafinil has been used as a treatment for the extreme tiredness (fatigue) some people get with MS. But we don't know if it works.

What is it?

Modafinil tablets (brand name Provigil) were first used to treat an illness that makes you keep falling asleep (called narcolepsy). It helps people with narcolepsy stay awake, and feel less tired. So doctors thought it might also help people with tiredness caused by other medical conditions.

How can it help?

We're not sure if it can help people with MS.

There's only been one small study looking at modafinil as a treatment for fatigue in people with MS.^[93] Modafinil didn't work any better than a dummy treatment (a placebo).

How does it work?

Modafinil works by changing the amounts of chemicals in the part of the brain that controls sleep and wakefulness.^[94]

Can it be harmful?

Stomach upset and difficulty sleeping are the most common side effects.^[93]

Modafinil can cause a very serious rash.^[95] This can be life-threatening and need treating in hospital. Talk to your doctor straight away if you get a rash while you're taking modafinil.

Some people taking modafinil have had problems that affected their mood and the way they thought.^[96] These problems included an unusually high mood, seeing things that weren't there, and having thoughts of suicide.

Modafinil isn't usually recommended for people who've had mental health conditions in the past.

Modafinil can interfere with other drugs that you might take for your MS. For example, it can interfere with drugs called benzodiazepines or with certain antidepressants. So be sure to talk to your doctor about your other treatments if you're thinking about trying modafinil tablets.^[97]

How good is the research on modafinil?

We only found one small study (a randomised controlled trial) of 115 people.^[98] Some people in the study took modafinil (brand name Provigil) for five weeks and some people took a dummy treatment (a placebo). People felt just as tired whether they took modafinil or the placebo. But this study is too small to be sure that modafinil doesn't work.