Armodafinil is the R-enantiomer of modafinil, a central nervous system (CNS) stimulant/wakefulness-promoting agent. It is used to improve wakefulness in patients with excessive sleepiness associated with narcolepsy, obstructive sleep apnea (OSA), and shift work sleep disorder (SWSD). It has a more sustained plasma concentration profile compared to racemic modafinil, potentially offering a longer duration of effect.
Adult: Narcolepsy or OSA: 150mg or 250mg orally once daily in the morning. SWSD: 150mg orally once daily, taken approximately 1 hour prior to the start of the work shift.
Note: Take orally with or without food. For SWSD, take 1 hour before work shift. Avoid taking late in the day to prevent insomnia. Tablet should be swallowed whole with water.
The exact mechanism is not fully understood. Armodafinil promotes wakefulness without generalized CNS stimulation. It is thought to act by selectively activating the hypothalamic wakefulness centers (tuberomammillary nucleus) and inhibiting sleep-promoting neurons in the ventrolateral preoptic nucleus (VLPO). It increases extracellular dopamine levels in the striatum, nucleus accumbens, and prefrontal cortex by inhibiting the dopamine transporter (DAT).
Pregnancy: Category C: Animal studies show adverse effects. No adequate human studies. Use only if potential benefit justifies potential fetal risk. Not recommended.
Driving: May impair ability to drive or operate machinery, especially until individual response is known. Caution advised against driving if experiencing side effects like dizziness or blurred vision.
| Cyclosporine | Armodafinil may reduce cyclosporine levels via CYP3A4 induction. Monitor levels. | Major |
| Warfarin | Armodafinil may increase warfarin metabolism (CYP2C9 induction), reducing INR. Monitor INR closely. | Major |
| Midazolam, Triazolam | Armodafinil may reduce benzodiazepine levels via CYP3A4 induction, reducing efficacy. | Moderate |
| Ethinyl Estradiol (Oral Contraceptives) | Armodafinil may reduce contraceptive efficacy via CYP3A4 induction. Use alternative or backup non-hormonal contraception. | Major |
| Clomipramine | Armodafinil may inhibit clomipramine metabolism, increasing its levels and risk of toxicity. | Moderate |
| Ketoconazole, Itraconazole | Strong CYP3A4 inhibitors may increase armodafinil levels. Monitor for adverse effects. | Moderate |
| Phenytoin, Carbamazepine | Strong CYP3A4 inducers may decrease armodafinil levels, reducing efficacy. | Moderate |
| Monoamine Oxidase Inhibitors (MAOIs) | Theoretical risk of hypertensive crisis. Avoid concurrent use or use with extreme caution. | Major |