Comparison of the Effects of Terazosin and Enalapril on Laboratory Stress Testing Blood Pressure in Patients with Essential Hypertension

It is the current opinion that an ideal antihypertensive drug should reduce blood pressure (BP) not only at rest but also during stressful situations. The current study was aimed to compare the effects of the selective α1‐adrenergic blocker terazosin (5 mg once daily) and of the angiotensin‐converting enzyme inhibitor enalapril (20 mg once daily) on cardiovascular response to a set of standardized laboratory stressors, such as mental arithmetic, handgrip test and cycle ergometry, in a group of 16 essential hypertensive patients. The study was a randomized, double‐blind, cross‐over trial preceded by a placebo run‐in period. Terazosin and enalapril had a comparable effect on resting BP, reducing systolic (SBP) and diastolic (DBP) blood pressure from 159.5 ± 13.9/101.6 ± 8.8 mm Hg during placebo by 7.8%/6.7% and by 11.3%/10.2%, respectively. The “response” rate to the two treatments was approximately the same, being 69% and 75% after terazosin and enalapril, respectively. During mental arithmetic, from an average of 181.6 ± 17.8/118.6 ± 11.5 mm Hg during placebo, BP was reduced by 11.5%/7.9% after terazosin and by 13.6%/8.5% after enalapril; during handgrip test, BP decreased from 207.2 ± 22.2/142.2 ± 13.6 mm Hg by 7.3%/8.4% after terazosin and by 7.7%/7.1% after enalapril; finally, during cycle ergometry, terazosin and enalapril lowered BP by 5.4%/6.7% and 7%/3.1%, respectively, from a placebo value of 215.5 ± 17.3/127.6 ± 11.2. No significant difference in antihypertensive efficacy was observed between the two drugs, either at rest and during stress testing. Neither terazosin nor enalapril induced any significant change in resting and stress testing heart rate. Our data suggest that doses of terazosin and enalapril able to reduce resting BP are also effective in lowering BP during a variety of stressful situations, and thereby are potentially able to ameliorate the impact of recurring stress‐induced increases of BP on the cardiovascular system.