Modafinil may cause muscle spasms

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The active substance Modafinil is one of the most important remedies against sleeping sickness (narcolepsy). However, its approval for the treatment of sleep apnea was withdrawn in 2011 due to an unfavorable risk-benefit profile. Modafinil is generally considered to be well tolerated, but in rare cases it can lead to headaches and restlessness. Children and adolescents only take the active ingredient after consulting a doctor. Here you can read everything you need to know about Modafinil.

This is how Modafinil works

Sleeping sickness, also known as drowsiness or narcolepsy, is a sudden onset of sleep attacks that are characterized by an irresistible urge to sleep during the day. This leads to partial or complete relaxation of the muscles (cataplexy) and sometimes hallucinations when falling asleep. Such a sleep attack usually lasts between 10 and 20 minutes. Those affected suffer greatly from the symptoms because they cannot foresee the attacks (for example at work).

One way of treating narcolepsy is to stimulate the central nervous system (spinal cord, brain), for example with modafinil. This keeps the patient awake during the day.

The effects of Modafinil are not yet fully understood. Part of the effect is based on the fact that the active ingredient binds to the docking points of the neurotransmitter adrenaline (so-called "α receptors"). Adrenaline is usually responsible for the body's wakefulness. The central nervous system is activated by the binding of the active substance to the α-receptors, and the patient stays awake during the day.

Modafinil uptake, breakdown and excretion

The active ingredient Modafinil is taken by mouth and almost completely (around 90 percent) absorbed from the intestine into the blood. It takes about an hour to take effect. The excretion of the drug takes a very long time, residues of the drug can still be detected in the body for up to a month after ingestion. The breakdown takes place in the liver.

When is Modafinil used?

Modafinil is used in the following area of ​​application (indication):

  • Sleep addiction with or without relaxation of the skeletal muscles (narcolepsy with or without cataplexy)

This is how Modafinil is used

The Modafinil dosage is 200 to 400 milligrams daily. The active ingredient is usually swallowed in the form of tablets with plenty of liquid (preferably a large glass of water). The intake should preferably take place in the morning so that the wakeful state extends over the day and less sleep disturbances occur.

Patients with kidney or liver problems receive a reduced dose.

What are the side effects of Modafinil?

Very often, that is, in more than ten percent of those treated, Modafinil causes side effects such as headaches.

Frequently, that is, in one to ten percent of those treated, restlessness, insomnia, anxiety, increased sweating and an accelerated pulse occur after ingestion.

Life-threatening allergic reactions occur very rarely.

What should be considered when taking Modafinil?

Drugs containing modafinil must not be used in conjunction with treatment with α-receptor blockers such as tamsulosin (for enlarged prostates) or mirtazapine (for depression).

Patients suffering from an addictive disorder are also not allowed to receive the active ingredient.


The active ingredient Modafinil can accelerate the breakdown of certain drugs and thus reduce their effect. These include:

  • Itraconazole (for fungal infections)
  • Amitriptyline (for depression)

If the active substance is administered at the same time as blood-thinning agents (such as warfarin), blood coagulation should be checked regularly.

Hormonal contraceptives (the “pill”) can make Modafinil less effective. Interactions are also possible with anti-seizure agents.

Ability to drive

Modafinil can change the ability to react because the active ingredient affects the central nervous system. Patients receiving the drug should wait for their individual reaction to the active ingredient and then decide together with the doctor whether they can actively participate in road traffic or not.

pregnancy and breast feeding period

Modafinil medication should not be used during pregnancy. There is little experience with the use during breastfeeding. Therefore, the doctor decides on a case-by-case basis.

How to get Modafinil medication

Modafinil drugs require a prescription. You can therefore only get them with a prescription from the doctor in the pharmacy.

How long has Modafinil been known?

Modafinil has been in use for decades. Due to an unfavorable risk-benefit profile, the drug's approval for the treatment of sleep apnea (brief cessation of breathing during sleep) was withdrawn in 2011. Only the use for the therapy of narcolepsy is allowed.

More interesting facts about Modafinil

Modafinil is misused to improve performance, for example before exams or competitions. He is on the list of prohibited doping substances. He was best known for a positive one Modafinil-Test of the athlete Kelli White, who wanted to increase her athletic performance with the active ingredient in 2003.

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