Modafinil: how it works, use, and side effectsModafinil is a non-amphetamine CNS stimulant used by people to stay awake and alert. In this article, we discuss its mechanism of action, indications, and adverse reactions.

Modafinil: basic information

Modafinil stimulates the central nervous system and makes a person awake and alert. It is banned in certain states and classified as a Schedule IV controlled substance in the United States. This means that a patient can obtain modafinil only with a doctor’s prescription and get a refill only up to 5 times in 6 months. Modafinil is produced in the form of oral (to be taken by mouth) tablets. The drug has many trade names, including:

• Provigil
• Resotyl
• Intensit
• Alertex
• Stavigile
• Vigil
• Mentix
• Wakelert
• Modasomil

What modafinil does to a patient:

• induces awakeness;
• stimulates locomotor activity;
• induces euphoria;
• alters feeling, mood, thinking, and perception (it is called psychoactive effect).

How modafninil acts in the body

It is yet unclear how exactly modafinil induces alertness. While its effect is similar to that of sympathomimetic compounds, such as methylphenidate and amphetamine, the chemical process appears to be different. The clinical data shows that modafinil suppresses dopamine reuptake. The drug elevated extracellular levels of dopamine in some brain areas of the tested animals. Additionally, the effect of the substance was reduced on specifically bred mice with a DAT (dopamine transporter) deficit. However, such drugs as alpha-methyl-p-tyrosine (dopamine synthesis inhibitor) or haloperidol (dopamine receptor antagonist) did not affect modafinil-induced locomotor activity when tested on rats.

What modafinil is used for

FDA-approved indications for modafinil include:

• Narcolepsy. Modafinil is a first-line treatment to alleviate daytime fatigue, but it does not help to reduce cataplexic symptoms.
• Sleep Work Shift Disorder. It is an affliction that affects people who work unusual hours. SWSD develops because of disrupted circadian rhythms and manifests by troubles with sleepiness at inconvenient times, fatigue, etc. Modafinil is a first-line treatment.
• Obstructive sleep apnea, in combination with a CPAP.

Modafinil is also considered for off-label (without specific FDA-approved indications) use in such cases, as:

• Fatigue induced by cancer or multiple sclerosis.
• Acute depressive episodes, unipolar and bipolar.
• ADHD.
• Cocaine dependence.

In some of these cases, the results of clinical research are mixed, but the drug remains a potential option nonetheless.

How to take modafinil

The usual dose of modafinil is 200 mg per day. For obstructive sleep apnea or narcolepsy, it is recommended to take the drug in the morning. To manage SWSD, modafinil should be administered an hour before the start of the work shift.

Precautions

A known hypersensitivity to any component of the drug is a contraindication for modafinil treatment. The drug is prescribed with extreme caution to patients who have acute hypersensitivity reactions (such as severe rash), preexisting tic disorders, chronic cardiovascular diseases, and a history of psychosis or mania. There is not enough clinical data on the effect of modafinil on pregnant patients. Spontaneous abortion and intrauterine growth restriction were reported in animal studies. Therefore, modafinil is a category C drug: risk for pregnancy and birth cannot be ruled out. Patients who receive modafinil treatment should be monitored. If any severe negative effect from the drug arises, the therapy is to be discontinued. Modafinil is often viewed by healthy people as a “brain stimulant” and considered as a way to improve working and studying performance. However, there are no strong results to support the benefits of this method. Moreover, the drug has a high potential for abuse, so we do not recommend trying to obtain and use it for such purposes.

Side effects

In general, modafinil is well-tolerated. The most common adverse reactions reported by 5% to 10% of patients include:

• headache;
• anxiety;
• insomnia;
• dizziness;
• decreased appetite;
• nausea;
• diarrhea;
• rhinitis.

We would like to remind you to always inform your doctor should you notice any side effects presumably connected to the use of medications you take.

Interactions with other drugs

Modafinil can alter the efficacy of certain drugs, such as zolpidem, cyclosporine, nimodipine, opioids, etc. If the person uses OCP (oral contraceptive pills aka birth control), it is recommended to implement a new method of contraception, as an addition or alternative to OCP, during modafinil therapy and until one month after finishing it. There are also drugs, such as ketoconazole, that can alter the effect and strength of modafinil. Always tell your doctor if you receive an ongoing treatment when being prescribed a new medication.