What is the recommended dose of modafinil (Provigil) for adults with narcolepsy, obstructive sleep apnea, or shift work sleep disorder?

Recommended Dosage of Modafinil for Adults with Sleep Disorders

For adults with narcolepsy, obstructive sleep apnea, or shift work sleep disorder, the recommended dose of modafinil is 200 mg taken once daily in the morning (for narcolepsy and OSA) or approximately 1 hour before the start of a work shift (for shift work disorder). 1

Dosing Guidelines by Condition

• For narcolepsy and obstructive sleep apnea (OSA): 200 mg taken orally once daily as a single dose in the morning 1
• For shift work sleep disorder (SWD): 200 mg taken orally once a day approximately 1 hour prior to the start of the work shift 1
• Doses up to 400 mg/day, given as a single dose, have been well tolerated, but there is no consistent evidence that this higher dose provides additional benefit beyond the 200 mg/day dose 1, 2

Special Population Considerations

• For elderly patients: Consider starting with a lower dose (100 mg) and close monitoring due to potential age-related changes in drug metabolism 2, 1
• For patients with severe hepatic impairment: Reduce the dosage to one-half of the recommended dose (100 mg daily) 1
• For treatment-naïve patients: A starting dose of 100 mg may be used and then increased to 200 mg as needed 2

Efficacy and Evidence Base

• Modafinil is a first-line agent for the treatment of excessive daytime sleepiness in narcolepsy and has gained favor over traditional stimulants 2
• The American Academy of Sleep Medicine strongly recommends modafinil for the treatment of narcolepsy in adults based on moderate quality evidence showing clinically significant improvements in excessive daytime sleepiness, disease severity, and quality of life 2
• Clinical trials have demonstrated that modafinil significantly increases daytime sleep latency and reduces excessive daytime sleepiness compared to placebo 3, 4
• Modafinil does not suppress cataplexy, a key symptom of narcolepsy type 1, so additional treatment may be needed for patients with this symptom 3

Monitoring and Follow-up

• More frequent follow-up is necessary when starting modafinil or adjusting doses 2
• Monitor for adverse effects including hypertension, palpitations, arrhythmias, irritability, or behavioral manifestations such as psychosis 2
• Patients should be questioned about excessive stimulatory effects or nocturnal sleep disturbances 2
• The Epworth Sleepiness Scale (ESS) is a useful tool for monitoring subjective sleepiness and response to therapy at each visit 2

Common Side Effects and Safety Considerations

• Most common adverse reactions include headache (34%), nausea (11%), and nervousness 1, 4
• Modafinil is a Schedule IV controlled substance due to its potential for abuse or dependency, though this potential is lower than with traditional stimulants 1, 3
• Serious rash requiring hospitalization, including Stevens-Johnson Syndrome, has been reported rarely 1
• Modafinil may reduce the effectiveness of oral contraceptives 1, 2
• Based on animal data, modafinil may cause fetal harm; human data are insufficient to determine risk 2

Important Clinical Pearls

• Modafinil does not affect sleep architecture according to polysomnography studies 4
• For OSA patients, modafinil is indicated to treat excessive sleepiness but not as treatment for the underlying obstruction; CPAP therapy should be optimized before and during modafinil treatment 1
• Unlike traditional stimulants, modafinil is not associated with rebound phenomena after treatment withdrawal 3
• Modafinil generally only improves sleepiness but does not eliminate it completely, so frequent reassessment of functional ability due to residual sleepiness is necessary 2