Effects of acute doses of zimelidine on REM sleep in rats

Sleep EEG (7 h) were obtained from 11 rats given 5, 10, and 20 mg/kg zimelidine, and a control dose of saline. Zimelidine significantly suppressed REM sleep, lengthened REM latency, and reduced total sleep time (TST) in a dose-dependent manner. Sleep latency was not affected except at the highest dose of zimelidine. Slow-wave sleep (SWS) was not affected at any dose. The results are discussed in terms of their implication for the use of zimelidine in the clinical treatment of depression.