Modafinil and Armodafinil – Mechanism of Action | Psychopharmacology | Clinical Application
Modafinil is a synthetic non-amphetamine stimulant approved for the first-line treatment of excessive sleepiness (ES). [Mignot, 2004]
Modafinil is a racemate, with the two enantiomers conferring approximately equipotent effects on the brain, although the R-isomer has a different pharmacological profile:
- Modafinil is a racemic mixture (R– and S-isomers) of diphenylmethylsulfinylacetamide
- Armodafinil is the R– and longer-lasting isomer of racemic modafinil. [Harsh et al. 2006]
Modafinil is indicated for ES caused by narcolepsy and sleep work shift disorder (SWSD) and obstructive sleep apnoea with continuous positive airway pressure use (res-OSA).
Armodafinil, like modafinil, is also a wakefulness promoter indicated for ES associated with narcolepsy, SWSD, and res-OSA.
However, it is important to note that in 2011 the European Medicines Agency removed the SWSD and res-OSA indications and restricted modafinil to the treatment of narcolepsy.
Calabrese JR, Frye MA, Yang R, Ketter TA Armodafinil Treatment Trial Study Network. Efficacy and safety of adjunctive armodafinil in adults with major depressive episodes associated with bipolar I disorder: A randomized, double-blind, placebo-controlled, multicenter trial. J Clin Psychiatry. 2014;75(10):1054–1061