Platelet deactivation by 5HT2-receptor blockade parallels the antihypertensive response to ketanserin.
Serotonin (5HT) has been implicated in thromboembolic complications and blood pressure elevation and both may be reduced with the 5HT2-receptor blocker ketanserin. In 17 patients with essential hypertension (WHO I and II, diastolic pressure V greater than or equal to 100 mmHg) blood pressure, platelet 5HT uptake, content and release as well as 5HT-induced shape change and aggregation were measured before and immediately after 8 weeks oral ketanserin at 20-40 mg twice daily. During ketanserin therapy, platelet 5HT release, shape change reaction and aggregation to 5HT were significantly reduced by more than 50%. These platelet effects were more pronounced in patients responsive to ketanserin (greater than or equal to 10% decrease of diastolic pretreatment pressure) and the fall in diastolic pressure correlated with the inhibition of 5HT-induced aggregation as well as the change in 5-hydroxy-indoleacetic acid (5HIAA) in platelet-rich plasma (PRP; P less than 0.05). Serotonin-receptor-independent platelet events were not affected by ketanserin. Ketanserin corrects 5HT2-receptor-mediated platelet function along with the reduction of blood pressure.
Amstein
R
R
Department of Medicine, University Hospital, Basel, Switzerland.
Fetkovska
N
N
Pletscher
A
A
Bühler
F R
FR
D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D007650:Ketanserin / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000378:metabolism*
D010975:Platelet Aggregation Inhibitors; D011985:Receptors, Serotonin; D012701:Serotonin; D007650:Ketanserin