No metabolic side effects of long-term treatment with verapamil in hypertension.

In a prospective, open study 45 patients (mean age fifty-three years) with essential hypertension were treated with verapamil for four to eight years (mean 5.3 years). Blood pressure was satisfactorily controlled (from 160/104 to 145/91) and the side effects were infrequent, mild, and often transient. Verapamil did not exert any unfavorable metabolic or hematologic effects over the years. HDL-cholesterol was moderately increased (mean 24%) and the other plasma lipids were unaffected. These data suggest that the calcium channel blocker verapamil is a metabolically safe drug to use as monotherapy in essential hypertension.

A new sustained-release formulation of verapamil in the treatment of hypertension.

The study was carried out in 24 patients with mild to moderate essential hypertension to assess the antihypertensive efficiency and tolerability of a new sustained-release formulation of verapamil (tablets containing 240 mg). The trial was conducted as a single-blind crossover study for periods of 4 weeks, preceded by a 2-week placebo period, comparing sustained-release verapamil twice daily with instant-release verapamil (conventional tablets of 80 mg) mg) 160 mg twice daily. Both regimens induced a significant reduction in blood pressure and heart rate, and this effect was (particularly for sustained-release verapamil) significant from the very first day of treatment. Both formulations were well tolerated. The pharmacokinetic data obtained and the even blood pressure reduction achieved demonstrate that this new verapamil formulation has sustained-release characteristics and is sufficient as a twice-daily medication in mild/moderate essential hypertension.

Instant and sustained-release verapamil in the treatment of essential hypertension.

In a series of controlled studies for periods of 4 to 6 weeks comprising 103 patients altogether, and in 1 long-term trial for 1 year, various dosages of instant and sustained-release verapamil were administered in the treatment of mild and moderate essential hypertension. One of these trials was a double-blind comparison with nifedipine, in which the 2 calcium antagonists had an equally good effect on blood pressure. A significant blood pressure reduction was achieved with verapamil both at rest and during isometric work in most patients. About 10% of the patients were nonresponders. Pharmacokinetic studies demonstrated great interindividual variations in plasma concentrations of verapamil and its active metabolite norverapamil. Except for 1 study, no significant correlation was found between drug concentration and blood pressure reduction. All formulations of verapamil were well tolerated by the patients, and adverse effects were generally mild and often transient. No negative metabolic effects were observed during long-term treatment; serum lipids, in particular, were unaffected. PQ intervals on the electrocardiogram were significantly but moderately prolonged. QRS and QT intervals were unchanged. No increase in body weight occurred. It is concluded that verapamil is an efficacious, safe drug and a first-line treatment alternative in mild and moderate essential hypertension. The recently developed sustained formulation of the drug renders a simple dosage regimen possible.

Studies on verapamil in the treatment of essential hypertension: a review.

Various doses of verapamil, using the conventional and sustained release formulations, have been administered for the treatment of mild or moderate hypertension in different controlled studies for periods of 4-6 weeks, involving a total of 103 patients, and in one long-term trial for 1 year in 12 patients. A double-blind comparison of verapamil and nifedipine showed that the two calcium antagonists had equal antihypertensive action. A significant blood pressure (BP) reduction was achieved with verapamil both at rest and during isometric exercise in the great majority of patients. No significant correlation was found between age and BP reduction, but pretreatment BP and pressure reduction correlated positively. Heart rate (HR) was moderately but significantly reduced by verapamil. The established wide interindividual differences in verapamil pharmacokinetics were confirmed. There was no significant correlation between plasma drug concentrations and BP reduction, but the dosage regimens with the highest mean plasma drug concentrations were associated with the greatest mean reduction in BP. A moderate, but significant, prolongation of AV-conduction was demonstrated. QRS- and QT-intervals were unaffected. Side-effects, with all formulations of verapamil, were generally mild and often transient. No significant haematological or metabolic effects were observed during long-term treatment. It is concluded that the calcium antagonist verapamil is an effective and safe drug. It can be considered as an alternative drug in mild and moderate essential hypertension.