Atenolol versus pindolol: side-effects in hypertension

This randomized crossover out-patient study was designed to compare the antihypertensive effects of atenolol and pindolol. After a wash-out period of two weeks in pretreated cases, 107 patients with essential hypertension were given either atenolol 100 mg once-daily or pindolol 20 mg slow release (SR) once-daily. Both atenolol and pindolol lowered blood pressure over the 24 week period. The diastolic blood pressure reduction was significantly greater (p less than 0.01) with atenolol than with pindolol. Before beta-blocker therapy, many patients had already experienced side-effects such as fatigue, sleep disturbances and dreams. This probably relates to the high sensitivity of the analogue scale used to assess side-effects, and to the high incidence of such symptoms in untreated patients. As the study progressed there was a reduction in the frequency of fatigue (p less than 0.03) and dreams (p less than 0.05) in both groups, whereas sleep disturbances significantly increased under pindolol (p less than 0.05) but decreased under atenolol (p less than 0.05). The only important side-effect difference between the two beta-blockers was the higher incidence of sleep disturbances with pindolol which may be due to the higher lipophilicity of this beta-blocker.