Modafinil: Drug Interactions & Side Effects

Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

Caffeine stimulates our body and might make us shaky. That side-effect is also possible with another medication that stimulates our body, modafinil. Learn about its interactions and side effects in this lesson.

What Is Modafinil?

Most of us can get by with drinking coffee to stay awake. Maybe an energy drink if we're really groggy. But for some people, staying awake thanks to caffeine isn't going to cut it. Those people might have narcolepsy, a neurologic sleep disorder.

One drug used to treat this disorder is modafinil, a type of medication that stimulates the brain. It's better known by its brand name of Provigil (like being 'pro-' 'vigil'ant).

Like any other drug, modafinil might have unwanted interactions with another drug. This lesson goes over some of these interactions and the side effects of modafinil itself.

Drug Interactions

Modafinil has dozens of very important drug interactions; we'll focus on just a few in more detail.

One drug interaction is between modafinil and a drug called fentanyl. Fentanyl is also known as Abstral among other brand names. It's a very powerful pain reliever. It's not something you'd use to control pain from a minor joint ache.

  • Regardless, when used together, modafinil might decrease the levels of fentanyl in a person's blood. This might make fentanyl less effective at controlling a person's pain.

Modafinil also has an important interaction with a drug called clopidogrel, better known by its brand name of Plavix. This is a drug that prevents platelets from sticking to one another. This means a person is less likely to form blood clots and thus suffer from a stroke or heart attack as a result of a blood clot.

  • The problem is that modafinil might decrease the effectiveness of clopidogrel. This might increase the chances a person will experience a stroke or heart attack as a result of a blood clot.

One of the signs of a heart attack, or sometimes a warning sign that one might occur in the future, is chest pain. But not any chest pain, like heartburn or something. No, chest pain stemming from a lack of oxygen to the heart muscle. This kind of chest pain is known as angina, or angina pectoris. Angina might be treated with ranolazine, also known as Ranexa.

  • If you take Ranexa, your doctor might not want to prescribe modafinil. That's because modafinil could reduce the levels of ranolazine in your body, making it less effective at treating angina.

People who have hepatitis C, a viral infection that could cause serious damage to the liver, need to be careful as well. This is namely true if they are taking a medication called sofosbuvir, or Sovaldi. Sofosbuvir is a medication used to treat hepatitis C.

  • Modafinil might make this drug less effective.

Side Effects

Modafinil also has its own stand-alone adverse effects that users need to be aware of. Again, just like the drug interactions, the number of side effects are many so this lesson only makes mention of some of them.

Some of the more common side effects of modafinil are:

  • Anxiety
  • Nausea
  • Nervousness
  • Headache

These side effects are considered to be relatively minor compared to the rare but major side effects, such as:

  • Black, tarry stools
  • Confusion
  • Shortness of breath
  • Shaking
  • Difficulty urinating

And if you overdose on this medication, you might experience insomnia, a pounding heartbeat and agitation.

If you experience any of the above, talk to a doctor right away.

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