Fatigue and MS: Part 3
Medications to promote wakefulness.
Despite making lifestyle changes, many patients with MS will nonetheless need a medication to promote wakefulness. The three most commonly-used medications are amantadine (Symmetrel®), modafinil (Provigil®), and stimulants such as Ritalin or Adderall. Note that none of these are FDA approved for this purpose.
1. Amantadine: Amantadine was originally used as an antiviral medication to treat influenza infections. Though its mechanism of action is not clear, it has since found a role as a medication to relieve fatigue in MS. Most patients require between 100-200mg daily. Common side effects include:
- trouble with concentration
- decreased appetite
- blotchy changes on the skin (especially at higher doses)
Many of these side effects will lessen with time. To prevent insomnia, this medication should not be taken too late in the day.
2. Modafinil: Modafinil is a medication used in the treatment of narcolepsy to help patients stay awake throughout the day. The evidence behind this medicine is mixed. Results from a small trial of 72 people in 2000 found that the lower dose of modafinil was effective in fighting fatigue, while the higher dose was not. A subsequent randomized, placebo-controlled, double-blind study of the medication found no difference between it and placebo. Nonetheless, based on clinical experience, many neurologists continue to try this medication in MS fatigue. The medication is usually given at doses of 100-200mg daily. To prevent insomnia, it should not be taken in the afternoon. Modafinil should not be taken in patients with serious cardiovascular problems or liver disease. It has also been associated with rare, but serious rashes. Many patients, in my experience, find that this medication helps at the beginning, but is less effective over time.
3. Stimulants: Stimulants are probably the class of medication that I use the most to treat fatigue in MS. This is a personal habit, largely because I have the most experience with these medications in treating ADHD from my psychiatry training. There are several different versions of these medications that are quite similar, but differ in subtle ways based on their chemical structure.
- Ritalin is methylphenidate, and it comes in a sustained release form called Concerta.
- Focalin is a variant of this in the form of dexmethylphenidate that also comes in an extended-release form.
- Adderall is a combination of dextroamphetamine and amphetamine. It comes in immediate and sustained release varieties.
- Vyvanse is lisdexamfetamine.
In my experience, these medications are quite effective in controlling fatigue, but they must be used with caution. They can often make people feel nervous and jittery, and, unlike the other medications, come with a potential for tolerance and abuse. These medications should be avoided in any patient with a history of substance abuse. Patients often have a decreased appetite on these medications, so they should not be used in patients with poor nutritional status.
When prescribing these medications to a patient, I remind them that they are just meant to make them feel better. As such, these medications should be taken only if they improve patient’s lives. If they do not, there is no point in taking them. Unlike many medications, they do not have to be taken every day to be effective, and can be taken on an “as needed basis.”