This medication is a Schedule IV drug.
To improve wakefulness in adult patients with excessive sleepiness associated with narcolepsy, obstructive sleep apnea/hypopnea syndrome (OSAHS), and shift work sleep disorder (SWSD): The normal adult dose is 200 mg given once a day in the morning. In patients with shift work sleep disorder, take 1 hour before their work shift. In patients with severe hepatic impairment or in the elderly, consideration should be given to use 100 mg given once a day.
Pharmacology/Pharmacokinetics:
The exact mechanism of modafinil is unknown. It has weak to no affinity for receptors for norepinephrine, serotonin, dopamine, GABA, adenosine, histamine-3, melatonin, and benzodiazepines. Modafinil does bind to the dopamine transporter and inhibits dopamine reuptake in some regions of the brain. However, effectiveness of modafinil is not inhibited by the dopamine receptor antagonist haloperidol. Oral absorption is rapid, with peak plasma levels occurring about 2-4 hours post dose. The l-isomer of modafinil has a half-dose of three times that of the d-isomer. At steady-state, the l-isomer accounts for 90% of the circulating modafinil. The effective elimination half-life of modafinil is 15 hours after multiple oral doses. Apparent steady states of total modafinil are reached after 2-4 days of dosing.
Drug Interactions:
May decrease plasma levels of ethinyl estradiol, triazolam, and cyclosporine. May increase plasma levels of diazepam, propranolol, and phenytoin. May increase the plasma levels of clomipramine and desipramine in patients deficient in CYP2D6 (poor metabolizers).
Contraindications/Precautions:
Contraindicated in patients with known hypersensitivity to modafinil or armodafinil. Serious rash, including Stevens-Johnson Syndrome, has occurred during treatment. Modafinil should be discontinued at the first sign of rash. Use with caution in patients with a recent history of myocardial infarction or unstable angina. Use a reduced dose in patients with hepatic impairment. Psychiatric adverse effects include mania, delusions, hallucinations, and suicidal ideations have occurred during therapy. Modafinil is not indicated for use in pediatric patients for any indication. Pregnancy Category C.
Adverse Effects:
The most common adverse effects are headache, nausea, anxiety, rhinitis, diarrhea, back pain, dizziness, insomnia. And dyspepsia. Serious RASH has occurred during treatment.
May be taken with or without food.
Contact a physician if the above side effects are severe or persistent.
Stop use and contact a physician at the first sign of an allergic reaction.
For patients with OSAHS or narcolepsy, take in the morning. For patients with SWSD, take 1 hour before shift work.
Avoid driving, operating machinery, or when mental alertness is required until your physician tells you it is okay.
Avoid alcohol while taking this medication.
Do not exceed prescribed dosage.
WARNING: This medication may be habit-forming.
Store in a cool, dry place away from sunlight and children.
If a dose is missed, skip it and return to normal dosing schedule.
