Comparative study of atenolol, metoprolol, metoprolol durules, and slow-release oxprenolol in essential hypertension.

Twenty-five patients with moderate essential hypertension (standing diastolic blood pressure 100-125 mmHg, phase 5) completed a single-blind placebo-controlled cross-over study comparing four week periods of treatment with atenolol 100 mg, metoprolol 100 mg, metoprolol durules 200 mg, slow-release oxprenolol 160 mg, and slow-release oxprenolol 320 mg respectively. All the drugs were significantly better than placebo at reducing resting blood pressure at 24 hours. Atenolol produced the greatest mean reduction of pressure and was the most effective drug for most patients, though the differences between atenolol and metoprolol durules were not statistically significant. These two drugs, however, were significantly more effective than the remainder. A similar ranking was seen with respect to the reduction of the blood pressure and heart rate response to exercise. None of the treatments had any significant effect on the patients' rating of perceived exertion during the exercise test.