Comparison of diltiazem and atenolol in young, physically active men with essential hypertension

Effects of atenolol versus enalapril on cardiovascular fitness and serum lipids in physically active hypertensive men

An ideal drug regimen for physically active hypertensive patients should not offset exercise-induced improvements in cardiovascular health or fitness. In this randomized, double-blind, placebo-controlled, crossover study of 39 physically active men with uncomplicated essential hypertension, we compared the effects of atenolol and enalapril on cardiovascular fitness and serum lipids. Drugs (atenolol, 50 or 100 mg once daily; enalapril, 10 or 20 mg once daily) were each administered for 4 weeks and each active drug period was preceded by 4 weeks of placebo therapy. Both drugs effectively (p < 0.001) lowered resting blood pressure when measured at the time of theoretical peak (i.e., 3 to 4 hours postdrug) and trough (i.e., 24 hours postdrug) drug blood levels. Atenolol reduced maximal oxygen uptake (by 7.3%, p < 0.001) 3 to 4, but not 24, hours after drug ingestion; no changes occurred with enalapril. Similarly, whereas serum lipids were essentially unchanged with enalapril, serum triglycerides (18.9% increase), high-density lipoprotein cholesterol (10.6% decrease), and ratio of low-density to high-density lipoprotein cholesterol (15.4% increase) were adversely impacted (p < or = 0.05) with atenolol. It is concluded that in contrast to enalapril, atenolol adversely impacts cardiovascular fitness and serum lipids and lipoproteins in physically active hypertensive men.

Comparison of the efficacy and safety of once-daily versus twice-daily formulations of diltiazem in the treatment of systemic hypertension. The Canadian Multicenter Diltiazem-CD Hypertension Trial Group

The efficacy and safety of optimally titrated once-daily (CD) and twice-daily (SR) diltiazem were compared in 111 patients with mild to moderate systemic hypertension [seated diastolic blood pressure (DBP) > or = 95 mmHg and < or = 114 mmHg] in a multicenter, randomized, double-blind, placebo run-in, parallel-group trial. Following a 4 week washout and placebo-controlled run-in period, patients were randomized to receive diltiazem CD 180 mg and matching placebo (n = 54), or diltiazem SR 90 mg bid (n = 57). Total daily doses were titrated from 180 mg to 360 mg to achieve a goal of seated DBP < 90 mmHg during a 6 week titration period. The patients continued to receive their optimal dose for a 6 week follow-up period. Ninety-six (96) patients (diltiazem CD: 47, diltiazem SR: 49) completed the study protocol, with 60% of the diltiazem CD and 55% of the diltiazem SR patients achieving the goal of seated DBP of < 90 mmHg (p = 0.685). Although significant decreases occurred in seated and standing measurements of diastolic and systolic BP and heart rate with treatment in both groups, there were no significant differences between treatment groups. Both medications were well tolerated, with a similar frequency of adverse effects [diltiazem CD: 24/54 (37%) patients; diltiazem SR: 24/57 (42.1%) patients] with the most frequently reported adverse effects being headache and edema.

Diltiazem: ten years of clinical experience in the treatment of hypertension

Diltiazem hydrochloride is a benzothiazepine derivative calcium-channel blocker with proven antianginal and antihypertensive capabilities. Its primary mechanism of action is vasodilatation, which results in diminished vascular resistance and improved perfusion to various vascular beds and target organs. The antihypertensive efficacy of diltiazem in various demographic groups has been studied and compared with diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, and other calcium-channel blockers. These studies have shown that the antihypertensive effect of diltiazem is similar to that of the other therapies. Diltiazem does not adversely affect electrolytes or carbohydrate or lipid metabolism, and it may have beneficial effects on the heart and kidneys. Diltiazem reduces myocardial hypertrophy and exerts antianginal effects on the heart through coronary vasodilation and reduction in the blood pressure double product. Diltiazem improves renal perfusion and attenuates proteinuria. These effects may be helpful in limiting the progression of renal injury. Overall, the efficacy and tolerability of diltiazem, as well as its salutary effects on the heart and kidneys, make it an important therapeutic consideration for patients with hypertensive disease.

Effects of atenolol and diltiazem-SR on exercise and pressure load in hypertensive patients

The effects of monotherapy with atenolol or diltiazem-SR on blood pressure, 24-h blood pressure (BP) load, and exercise capacity were tested in patients with mild to moderate (stages I and II) essential hypertension. After 3-week single-blind placebo therapy, patients with sitting diastolic blood pressure (SDBP) of 94-114 mmHg were randomized to atenolol 50 mg/day (62 patients) or diltiazem-SR 90 mg b.i.d. (60 patients) in a double-blind parallel study. Depending on SDBP response, the dose was increased to 100 mg/day for atenolol and 180 mg b.i.d. for diltiazem-SR. Twenty-four-hour ambulatory blood pressure measurements and exercise tolerance test by the Bruce protocol were done at the end of placebo and active treatment. Compared with placebo, both atenolol and diltiazem-SR significantly decreased heart rate (HR), sitting systolic blood pressure (SSBP), SDBP, ambulatory BP, BP load for waking and sleeping hours, area under the BP curve, rate-pressure product (p < 0.001), and exercise time (NS). Atenolol exerted a greater effect on ambulatory BP, HR, rate-pressure product, waking diastolic BP load, and area under the 24-h BP curve. The drugs were well tolerated and caused no serious side effects necessitating discontinuation of treatment. These findings indicate that (1) monotherapy for hypertension with atenolol or diltiazem-SR is effective and well tolerated, (2) it decreases the 24-h BP load, (3) it does not interfere with exercise capacity.

Exercise prescription for hypertensive patients

Physical conditioning has been suggested as a useful adjunct or alternative to pharmacologic therapy in the treatment of borderline or mild hypertension. This recommendation stems from numerous studies that have demonstrated modest decreases in blood pressure in hypertensive individuals. Exercise guidelines should be based on preliminary exercise testing and modified to accommodate those patients who are taking a variety of antihypertensive medications. Although pure isometric exercise is generally contraindicated in hypertensive patients, potentially valuable training activities that involve a substantial static component, including arm crank ergometry and mild-to-moderate load weight training, probably requires individual assessment.

Calcium metabolism, calcium-channel blocking agents, and hypertension management

Increasing evidence has suggested that a disturbance of cellular calcium metabolism may have a role in initiating and maintaining elevated systemic vascular resistance in essential hypertension. Controversy exists over whether calcium can alleviate or exacerbate the hypertensive process, and diversity of calcium metabolism in hypertensive patients has been proposed. Calcium-channel blocking agents are potent vasodilators capable of correcting the elevated systemic vascular resistance. Clinical studies have shown that these drugs have antihypertensive efficacy comparable to established agents. The elderly, blacks, and patients with low renin activity respond well to calcium-channel blockers. These drugs may also offer potential advantages over established antihypertensive agents in patients with other coexisting diseases. Sustained release formulations have been developed, and initial experience with long-term efficacy and tolerability is encouraging. The calcium-channel blockers may become first-line therapy for treatment of hypertension in selected patients.