EFFECT OF MODAFINIL ON PLASMA MELATONIN, CORTISOL AND GROWTH-HORMONE RHYTHMS, RECTAL TEMPERATURE AND PERFORMANCE IN HEALTHY-SUBJECTS DURINGA 36 H SLEEP-DEPRIVATION

Modafinil is an alerting substance which has been used successfully to treat narcolepsy. Nothing is known about its effect on hormone secret ions. For this purpose, eight healthy young men were enrolled in a dou ble blind trial to test the effects of modafinil on daily plasma melat onin, 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 week s 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 rando mly attributed during N1 at 22 h and 8 h. As expected, performance was improved after modafinil administration and body temperature was main tained or increased. Plasma melatonin and cortisol profiles were simil ar after modafinil and placebo administration. The levels observed dur ing 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 secretor y episodes was unchanged. These data show that the alerting property o f modafinil is not related to an alteration of hormone profiles and su ggest that the acute modafinil administration is devoid of short-term side-effects.