Increased platelet adhesion and aggregation in hypertensive patients: effect of atenolol.

Abstract
Fourteen patients with established hypertension followed a double‐blind crossover‐styled trial to study the effects of 100 mg/day atenolol compared to placebo. Atenolol was found to be an effective antihypertensive agent, reducing both systolic and diastolic blood pressure. Hypertensive patients appear to have increased in vitro platelet adhesion and aggregation. Atenolol significantly reduced platelet adhesion, but had little effect on aggregation. This may be important in contributing towards the now‐recognised cardio‐protective effect of the beta‐adrenoceptor blocking agents. Blood chemistry and haematological parameters were unchanged; but whereas plasma cholesterol and plasma triglyceride levels remained normal, there was a significant fall in plasma high‐density lipoprotein cholesterol levels. Side effects were very few.