How Modafinil Promotes Wakefulness

Medically reviewed by Steven Gans, MD

What is the most important information I should know about modafinil?

You should not take modafinil if:

• you have unstable angina or have recently had a heart attack; or

• you have a known hypersensitivity to modafinil or armodafinil.

Modafinil is sometimes called a "wakefulness-promoting agent." This medication works to reduce sleepiness caused by conditions including narcolepsy, sleep apnea, and shift work sleep disorder.

It is available as a tablet taken by mouth, usually once daily. Most people who work during the day take the drug in the morning. However, shift workers taking the medication to promote wakefulness take it before their shifts begin.

This article discusses how modafinil works to promote wakefulness. It also explores the potential side effects of the medication and its potential for misuse.

How Modafinil Works

Modafinil, also known by its brand name Provigil, is a central nervous stimulant. Central nervous stimulants are substances that stimulate the brain. These medications impact the body by speeding up physical and mental processes.

Researchers believe that this drug works by affecting chemical messengers known as neurotransmitters.

Modafinil appears to make chemical messengers like monoamines, catecholamines, dopamine, serotonin, adenosine, and noradrenaline more available in the spaces between cells. Modafinil affects several parts of the brain, including the hypothalamus, hippocampus, and amygdala.

The result of these changes is reduced sleepiness. Because it is a mild stimulant, modafinil may produce less anxiety, irritability, and jitteriness than some other stimulants.

What Does Modafinil Treat?

Modafinil is used to treat problems with sleep, arousal, and wakefulness. Some conditions treated with modafinil include:

• Depression

• ADHD

• Narcolepsy

• Obstructive sleep apnea

• Sedation due to medications

• Shift-work sleep disorder

• Traumatic brain injury

On-Label and Off-Label Uses

The U.S. Food and Drug Administration has approved modafinil to treat daytime sleepiness in individuals with narcolepsy, shift work disorder, and obstructive sleep apnea. The label notes that it is intended to treat sleepiness in obstructive sleep apnea, not as a treatment for the condition itself. It may be prescribed off-label to treat sleepiness associated with other conditions.

Modafinil can be effective in promoting wakefulness when taken as prescribed. Follow your healthcare provider's instructions. Do not take your medication in a larger dose, more frequently, or for a longer period than you have been instructed to do by your prescriber.

This medication should also not be used as a substitute for adequate sleep. Continue maintaining good sleep habits and get enough rest at night while taking this medication. If you still struggle to maintain wakefulness even when taking modafinil, talk to your doctor about your symptoms and treatment options.

Dependence and Addiction

Modafinil is categorized as a Schedule IV controlled substance, which means it has a low potential for dependence and addiction.

This medication produces effects consistent with other stimulants. People with a history of drug use or a stimulant use disorder should be monitored for signs of misuse.

In one clinical trial, dependence was not observed following nine weeks of modafinil use. However, people experienced a return of sleepiness symptoms after stopping the medication.

If you are taking modafinil, do not stop taking your medication without talking to your doctor first. While the risk of withdrawal symptoms is low, you should discuss the possibility with your doctor and talk about other ways to manage your symptoms of sleepiness.

Modafinil is less addictive than other psychostimulants like amphetamine. However, some evidence suggests that dependence is still possible.

Modafinil Side Effects

Modafinil can also cause some serious side effects and should be taken only when prescribed by a healthcare provider. Common side effects of modafinil include agitation, anxiety, nausea, and vomiting.

Other potential side effects include:

• Blisters

• Chest pain

• Constipation

• Diarrhea

• Difficulty breathing

• Hallucination

• Hives

• Hoarseness

• Insomnia

• Irregular heartbeat

• Rash

• Suicidal ideation (thoughts of suicide)
  

• Sweating
  

Some of these are serious and potentially dangerous. If you experience any of these side effects, contact your healthcare provider.

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 988 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.

Overdose

Some side effects may result from an overdose of modafinil. Symptoms of modafinil overdose may include:

• Agitation

• Chest pain

• Confusion

• Diarrhea

• Insomnia

• Heart palpitation

• Nausea

• Restlessness

• Tremor
  

Call emergency services or a physician immediately if you suspect an overdose.

Contraindications

Modafinil isn't for everyone, and before your physician prescribes you this medication, you should inform them if you:

• Are allergic to modafinil or armodafinil (a similar drug)

• Take antidepressant medications including SSRIs, TCAs, and benzodiazepines

• Take antiseizure medications like phenytoin and carbamazepine

• Take antifungal medications like itraconazole and ketoconazole

• Use or are dependent on alcohol or other substances

• Take any vitamins, nutritional supplements, or herbal supplements
  

People who have unstable angina or recently had a heart attack shouldn't be given modafinil.

Furthermore, it's unclear the effect that modafinil has on the seizure threshold, or a person's likelihood to have a seizure. Because of this, modafinil should be used with caution in people with epilepsy and other seizure disorders.

There are no long-term studies on the effects of modafinil on the brain. A physician must carefully consider whether to prescribe modafinil and weigh the benefit of its stimulant properties with potential side effects.

It is essential to understand that if your healthcare provider has prescribed modafinil, this decision was based on your specific needs and characteristics. You should only take modafinil if it has been prescribed to you by a physician or other healthcare professional.