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Modafinil

Brands and Forms

  • Provigil
    • tablet: 100mg, 200mg
  • Alertec (Canada)

Uses of Modafinil

Modafinil is used most commonly for reducing excessive sleepiness in individuals with Narcolepsy, Sleep Apnea, and Shift-Work Sleep Disorder. It can also be used to help treat Attention-Deficit/ Hyperactivity Disorder (ADHD) and Bipolar Depression.

How Modafinil Works

The exact mechanism of action of Modafinil remains unknown. It presumably enhances activity in the hypothalamic wakefulness center (tuberomammilary nucleus), and may also increase dopamine transmission in the brain.

Cautions when Using Modafinil

In patients with severe hypertension or heart disease (including arrhythmias, mitral valve prolapse, unstable angina, or recent myocardial infarction), obtain the advice of a cardiologist before using Modafinil.

Modafinil can induce Manic or Mixed Episodes and Psychosis.

Use with caution in people with a history of substance abuse, as Modafinil has potential for abuse due to its euphoric effects.

Dosing of Modafinil

The dose of Modafinil is 200mg once a day in the morning when used for all of its purposes other than Bipolar Depression. For Bipolar Depression, initial dose is 100mg per day, and can be increased to 200mg/day after a couple of weeks if necessary.

Lower doses, around 100mg/day, may be best for targeting symptoms of difficulty concentrating and depression. Higher doses may be best for targeting excessive sleepiness.

A gradual taper is not required when wanting to stop Modafinil. Increased sleepiness may occur after discontinuation.

Onset of action

Reduced sleepiness and improved concentration can be felt immediately. Improvement in depressed mood may take two weeks.

Kidney impairment

Use with caution. Dose reduction in recommended.

Liver impairment

Reduce dose by 50%.

Side-effects of Modafinil

Below is a list of most of the reported side-effects of Modafinil. Most of these side-effects occur in only a minority of individuals, and many also resolve with time while the medication is continued.

Cardiovascular: hypertension; palpitation; tachycardia; vasodilatation.

Central Nervous System: headache; dizziness; insomnia; paresthesia; somnolence; confusion; dyskinesia; emotional lability; hypertonia; tremor; vertigo.

Dermatologic: herpes simplex; excessive sweating; serious rash including Stevens-Johnson syndrome and toxic epidermal necrolysis (very rare).

Endocrine/ Metabolic: elevated lipids and cholesterol.

Eyes, Ears, Nose and Throat: rhinitis; pharyngitis; abnormal vision; amblyopia; epistaxis; eye pain.

Gastrointestinal: nausea; diarrhea; dyspepsia; appetite loss; dry mouth; constipation; flatulence; mouth ulceration; taste perversion; thirst; abnormal liver functions.

Genitourinary: hematuria; pyuria.

Hematologic: eosinophilia.

Muskuloskeletal: back pain; neck rigidity.

Psychiatric: anxiety; agitation; worsening depression; emotional lability; suicidal thoughts and gestures; Manic or Mixed Episodes; psychosis.

Respiratory: asthma.

Common side-effects of Modafinil

Headache, nausea.

Rare but serious side-effects of note of Modafinil

Serious rash including Stevens-Johnson syndrome and toxic epidermal necrolysis.

Modafinil overdose

Aggressiveness, agitation, anxiety, confusion, diarrhea, excitation, insomnia, irritability, nausea, nervousness, palpitations, sleep disturbances, tremor.

Modafinil and pregnancy

Category C: some animal studies show adverse effects at very high doses, but no controlled human studies have been done; should only be used in pregnancy if clearly needed and if benefits outweigh potential risks.

Medical Monitoring for Modafinil

None for healthy individuals.

Drug Interactions with Modafinil

  • Modafinil may increase blood concentrations of various antidepressants, Diazepam, Phenytoin, and Propranolol.
  • Modafinil may reduce the effectiveness of oral contraceptives, and this effect can continue for up to one month after Modafinil has been stopped.
  • Modafinil blood concentrations can be lowered by Carbamazepine, and Modafinil can lower its own levels over time.
  • Modafinil blood concentrations can be increased by Fluoxetine and Fluvoxamine.
  • Modafinil may alter the effects of Warfarin
  • Methylphenidate can delay the absorption of Modafinil by one hour.
  • Modafinil can lower blood concentrations of Cyclosporin and Triazolam.
  • Use caution when combining Modafinil with an MAOI.