Armodafinil is the (R)-enantiomer of the wakepromoting compound
modafinil (racemic), with a considerably longer half-life of 10-15 hours.
Armodafinil (developed by Cephalon, Frazer, PA, USA) was approved in June 2007 for the treatment of excessive
sleepiness associated with
narcolepsy,
obstructive sleep apnea syndrome and shift work disorder, and the indications are the same as those for
modafinil. Like
modafinil, the mechanisms of action of
armodafinil are not fully characterized and are under debate. Clinical trials in these
sleep disorders demonstrated an enhanced efficacy for wake promotion (wake sustained for a longer time period using doses lower than those of
modafinil). The safety profile is consistent with that of
modafinil, and
armodafinil is well tolerated by the patients. Like
modafinil,
armodafinil is classified as a non-
narcotic Schedule IV compound. Many patients with excessive
sleepiness may prefer the longer duration of effect and may have better compliance (with low doses) with
armodafinil. The commercial challenge to
armodafinil may come from generic
modafinil, which may become available in 2012, as well as from classical
amphetamine and
amphetamine-like compounds (for the treatment of
narcolepsy).