Description
Provigil (modafinil)
Provigil contains modafinil, a wakefulness-promoting agent used for narcolepsy, obstructive sleep apnea where daytime sleepiness persists despite airway treatment, and shift work sleep disorder. Available in 100 mg and 200 mg tablets. It’s structurally unrelated to amphetamines, though it affects some overlapping neurotransmitter systems — dopamine reuptake inhibition is part of its mechanism, along with effects on histaminergic wake-promoting neurons in the hypothalamus. The exact mechanism of its wake-promoting action isn’t fully characterized.
Dosing
Standard adult dose: 200 mg once daily, taken in the morning for narcolepsy and sleep apnea. For shift work disorder, one dose taken one hour before the start of the work shift. The half-life is approximately 12 to 15 hours; residual alerting effects can persist into the evening, which is why dosing in the morning matters for most indications.
Older patients or those with significant hepatic impairment should start at 100 mg. The dose should not exceed 200 mg per day in hepatic impairment. Maximum dose in the general adult population is 200 mg, though some clinical studies have used higher doses without demonstrating additional benefit. Maximum frequency: one dose per 24-hour period.
Contraindications
Moderate to severe uncontrolled hypertension. Cardiac arrhythmias. Hypersensitivity to modafinil or armodafinil. History of serious dermatological reactions (Stevens-Johnson syndrome) with modafinil. Not recommended for children — safety in pediatric populations outside of narcolepsy under specialist supervision has not been established.
Hormonal contraceptives
Modafinil induces CYP3A4, reducing the plasma levels of drugs metabolized by this enzyme — including hormonal contraceptives. Women using oral contraceptive pills or implants should use an alternative or additional contraceptive method during modafinil treatment and for one month after stopping.
Controlled substance status
Modafinil is a Schedule IV controlled substance in the United States. Dependence has been reported in the literature; abuse potential, while considered lower than classical stimulants, is not zero. Clinical context and legitimate indication matter.
Side effects
Headache, insomnia, nervousness, anxiety, nausea, diarrhea, dizziness, and palpitations are the most commonly reported. Serious skin reactions — Stevens-Johnson syndrome and toxic epidermal necrolysis — have been reported rarely but require immediate discontinuation if they occur. Tachycardia and hypertension can occur at standard doses and require monitoring in patients with underlying cardiovascular disease.