Efficacy and tolerability of extended-release felodipine and extended-release nifedipine in patients with mild-to-moderate essential hypertension.

The efficacy and tolerability of extended-release felodipine (felodipine-ER) and nifedipine gastrointestinal therapeutic system (nifedipine GITS) were compared in a multicenter, prospective, open-label clinical trial of 277 patients with mild-to-moderate uncomplicated essential hypertension (sitting diastolic blood pressure [SiDBP] > or = 95 and < or = 115 mm Hg). After a 3-week washout period, patients were randomized to receive felodipine-ER (5 mg once daily) or nifedipine GITS (30 mg once daily); during a subsequent 6-week titration phase, the once-daily felodipine-ER dose could be increased to 10 mg and the nifedipine GITS dose to 60 or 90 mg in an attempt to achieve adequate blood pressure response (SiDBP < or = 90 mm Hg, or < 100 mm Hg with a > 10-mm Hg reduction from baseline, as measured 24 hours after dosing [trough]). At the end of titration, the mean daily doses of felodipine-ER and nifedipine GITS were 8 and 50 mg, respectively. Mean changes in sitting systolic blood pressure (SiSBP)/SiDBP were -14/-12 and -16/-13 mm Hg, respectively. All reductions were significant when compared with baseline (P < 0.01), but there were no significant differences between treatment groups. Adequate blood pressure response occurred in 77% of the felodipine-ER group and 80% of the nifedipine GITS group; this difference was not significant. Blood pressure changes were similar among sex and race subgroups. A higher percentage of older patients (> 55 years of age) than younger patients (< or = 55 years of age) reached goal SiDBP with both drugs. Patients with adequate SiDBP response continued receiving their assigned medication for an additional 6-week maintenance period. Reductions in SiDBP and SiSBP from baseline continued to be significant in both treatment groups. No clinically important changes in heart rate were noted. A total of 28 patients (15 in the felodipine-ER group and 13 in the nifedipine GITS group) withdrew from the study because of inadequate blood pressure response. At least one adverse experience occurred in 55% of the felodipine-ER group and 63% of the nifedipine GITS group, prompting withdrawal of 14 patients (10%) and 16 patients (11%), respectively. Headache and edema were the most common adverse experiences. The incidence and pattern of adverse experiences did not differ significantly between treatments. The results of this study demonstrate that once-daily felodipine-ER and nifedipine GITS are similarly highly effective and generally well tolerated in patients with essential hypertension.