title: Sedative and cardiovascular effects of clonidine and nitrazepam.
abstract: Five healthy male subjects, aged 26 to 35 yr, received single oral doses of clonidine 0.3 mg, nitrazepam 20 mg, or placebo double-blind with an interval of at least 1 wk between each treatment. Clonodine induced a maximal fall in systo9lic blood pressure from 104.2 +/- 1.6 to 84.7 +/- 1.4 mm Hg (mean +/- SEM) after 3.5 hr and nitrazepam from 102.9 +/- 1.9 to 90.3 +/- 2.6 mm Hg after 1.0 hr while after placebo blood pressure rose steadily from 102.5 +/- 2.9 to 109.6 +/- 3.5 mm Hg at the end of the 8-hr study. Total sleep time increased from 90.3 +/- 2.5. min after placebo to 256.2 +/0 21.0 min after clonidine (p < 0.001) and 281.0 +/- 40.3 min after nitrazepam (p < 0.001). Stage I sleep increased from 49.7 +/- 11.2 to 76.9 +/- 10.2 min after clonidine and to 76.3 +/- 25.2 min after nitrazepam (p < 0.0), while the greatest increase was observed in stage II: 230.7 +/- 25.6 min after clonidine and 236.6 +/- 35.4 min after nitrazepam compared with only 48.5 +/- 15.8 min after placebo (p < 0.001). Plasma norepinephrine did not change after placebo but fell after nitrazepam from 0.28 +/- 0.04 to 0.14 +/- 0.02 ng/ml after 3 hr (p < 0.05) and after clonidine from 0.23 +/- 0.07 to 0.07 +/- 0.02 ng/ml after 2 hr (p < 0.01). Clonidine and nitrazepam both induced similar hypnotic and hypotensive effects with some evidence that this might be due to a reduction in sympathetic tone.
mesh_terms: D000328:Adult; D001569:Benzodiazepines / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D002395:Catecholamines / Q000652:urine; D003000:Clonidine / Q000494:pharmacology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives; D008125:Locus Coeruleus / Q000187:drug effects; D008297:Male; D009567:Nitrazepam / Q000494:pharmacology*; D009638:Norepinephrine / Q000097:blood; D011930:Reaction Time / Q000187:drug effects; D012890:Sleep / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000187:drug effects; D013997:Time Factors
chemical_list: D002395:Catecholamines; D006993:Hypnotics and Sedatives; D001569:Benzodiazepines; D009567:Nitrazepam; D003000:Clonidine; D009638:Norepinephrine