Effect of modafinil on plasma
melatonin, cortisol and growth hormone rhythms, rectal temperature and
performance in healthy subjects during a 36 h sleep deprivation.
Brun J; Chamba G; Khalfallah Y; Girard P; Boissy I;
Bastuji H;
Sassolas G; Claustrat B
Service de Radiopharmacie et Radioanalyse,
Centre de
Medecine Nucleaire, Hopital NeuroCardiologique, Lyon, France.
Abstract
Modafinil is an alerting substance which has been used successfully
to treat narcolepsy. Nothing is known about its effect on hormone
secretions. For this purpose, eight healthy young men were enrolled in
a double blind trial to test the effects of modafinil on daily plasma
melatonin, cortisol and growth hormone (GH) rhythms. Blood was sampled for
hormone assays, every hour during the daytime and every 30 min during the
nighttime. In addition, rectal temperature and mental performances were
determined during the study which comprised 3 sessions, two weeks apart: a
24 h control session including a night with sleep (S1) and two 48 h sessions
S2 and S3 with a sleep-deprived night (N1) followed by a recovery night
(N2). Modafinil (300 mg x 2) or placebo were randomly attributed during N1
at 22 h and 8 h. As expected, performance was improved after modafinil
administration and body temperature was maintained or increased.
Plasma melatonin and cortisol profiles were similar after modafinil and
placebo administration. The levels observed during the recovery and the
control nights (N2) displayed no difference. For GH, during both sleep
deprived nights, secretion was dramatically reduced compared with the
control one, although the number of secretory episodes was unchanged. These
data show that the alerting property of modafinil is not related to
an alteration of hormone profiles and suggest that the acute modafinil
administration is devoid of short-term side-effects.
