Armodafinil is the R-enantiomer of modafinil, a wake-promoting agent, that primarily affects areas of the brain involved in controlling wakefulness. Armodafinil is an indirect dopamine receptor agonist; both armodafinil and modafinil bind in vitro to the dopamine transporter and inhibit dopamine reuptake. Armodafinil tablets are indicated to improve wakefulness in adult patients with excessive sleepiness associated with obstructive sleep apnea (OSA), narcolepsy, or shift work disorder (SWD). Once-daily armodafinil was generally well tolerated in adult patients with excessive sleepiness associated with OSA (despite treatment of the underlying condition), narcolepsy or SWSD.

R-(-)-modafinil acid is a major metabolite of armodafinil, a wakefulness-promoting agent for oral administration. It does not appear to contribute to the CNS-activating properties of the parent compound.

Modafinil acid is a metabolite of modafinil, a wake-promoting agent for oral administration. Orally administered modafinil is extensively biotransformed in the liver to the inactive metabolites modafinil acid and modafinil sulphone, before being eliminated primarily in the urine (elimination half-life 9 to 14 hours). Modafinil acid was the major urinary metabolite, which accounted for 35% to 60% of the dose. Two major metabolites of modafinil, modafinil acid, and modafinil sulfone, do not appear to contribute to the CNS-activating properties of modafinil.