Model insomnia, noise, and methylphenidate, used for the evaluation of hypnotic drugs.

Experimental sleep disturbance (model insomnia) was produced by intermittent white noise and the administration of 10 mg of methylphenidate (MPD). The effects of flurazepam (FZP) 15 mg and triazolam (TZM) 0.25 mg on these models was investigated. All night sleep polygraphy was performed on 8 normal male subjects under each of the following 9 conditions: baseline, TZM 0.25 mg, FZP 15 mg, white noise alone, noise and TZM, noise and FZP, MPD alone, MPD and TZM, and MPD and FZP. A reduction in total sleep time and stage were (S-REM) and an increase in the wakening stage were observed with both noise and MPD. Stage 4 sleep was reduced only by MPD. Administration of TZM or EZP did not cause any significant change in sleep parameters. These drugs in combination with noise or MPD resulted in almost complete recovery of the sleep disturbance induced by noise or MPD, except for a reduction in S-REM. These results indicate that model insomnia, particularly MPD insomnia, will assist in the evaluation of hypnotic drugs.