Hypotensive and antiplatelet actions of motapizone depend on dose and time after ingestion.
Single doses of motapizone 1 to 10 mg were given to 12 healthy subjects. Before and up to 8 h after each dose the blood pressure and heart rate were measured, as well as thrombocyte aggregation "ex vivo" with collagen, ADP and adrenaline. Motapizone produced a dose-dependent reduction in diastolic blood pressure and an increase in heart rate. These effects were demonstrated with individual variations after 1 to 3 mg and as a rule they were very marked after more than 6 mg. With the highest dose (mean 7.7 +/- 2.3 mg) the diastolic pressure fell by an average of 23% 1 h after medication as compared to with the baseline values. At the same time there was marked inhibition of thrombocyte aggregation, which also became apparent after about 3 mg and increased in proportion to the dose. The inhibition of aggregation peaked after 2 h and had disappeared within 8 h. The inhibition of ADP-induced aggregation was particularly marked.
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D002317:Cardiovascular Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D011724:Pyridazines / Q000097:blood / Q000494:pharmacology*
D002317:Cardiovascular Agents; D005343:Fibrinolytic Agents; D011724:Pyridazines; C051270:motapizone