Armodafinil is the R-enantiomer of modafinil, a non-amphetamine, wakefulness-promoting agent. It is a central nervous system (CNS) stimulant used to treat excessive sleepiness associated with narcolepsy, obstructive sleep apnea (OSA), and shift work sleep disorder (SWSD). It promotes wakefulness by selectively targeting areas of the brain involved in sleep regulation, with a lower potential for abuse and a more favorable side effect profile compared to traditional stimulants.
Adult: Narcolepsy or OSA: 150mg to 250mg once daily in the morning. SWSD: 150mg once daily, taken approximately 1 hour before the start of the work shift. Note: The 50mg strength is often used for dose titration, initiation in sensitive patients, or dose adjustment.
Note: Take orally, with or without food. For SWSD, take 1 hour before work shift. Swallow tablet whole with water. Avoid taking in the late afternoon or evening to prevent insomnia. Do not crush or chew.
The exact mechanism is not fully understood. Armodafinil is believed to promote wakefulness by selectively activating the hypothalamus and other brain areas involved in sleep/wake regulation. It increases neuronal activity in the tuberomammillary nucleus (a source of histamine) and inhibits dopamine reuptake via the dopamine transporter (DAT). Unlike amphetamines, it does not appear to cause widespread stimulation or significant effects on monoamine release.
Pregnancy: Category C: Animal studies show adverse effects. No adequate human studies. Use only if potential benefit justifies potential fetal risk. May reduce efficacy of hormonal contraceptives.
Driving: May impair ability to drive or operate machinery, especially until individual response is known. Caution 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). Monitor INR closely. | Major |
| Midazolam, Triazolam | Armodafinil reduces levels via CYP3A4 induction, decreasing efficacy. | Moderate |
| Ethinyl Estradiol (Oral Contraceptives) | Armodafinil induces metabolism, reducing contraceptive efficacy. Use alternative non-hormonal methods. | Major |
| Clomipramine | Increased risk of CNS stimulation. Monitor for anxiety, insomnia. | Moderate |
| Ketoconazole, Itraconazole | Strong CYP3A4 inhibitors may increase armodafinil levels. Monitor for side effects. | Moderate |
| Phenytoin, Carbamazepine | Strong CYP3A4 inducers may decrease armodafinil levels. Dose adjustment may be needed. | Moderate |
| Monoamine Oxidase Inhibitors (MAOIs) | Risk of hypertensive crisis. Avoid concurrent use. | Major |