Differential effects of once-daily antihypertensive drugs on blood pressure, left ventricular mass and sympathetic activity: Nifedipine-GITS versus felodipine-ER versus enalapril.
BACKGROUND
Recent meta-analyses suggest that once-daily dihydropyridines and angiotensin-converting enzyme inhibitors cause similar decreases in left ventricular (LV) mass for comparable decreases in blood pressure (BP). However, some dihydropyridines, such as felodipine-extended release (ER), still increase sympathetic activity and may, therefore, be less effective in decreasing LV mass.


OBJECTIVE
To evaluate the effects of long term antihypertensive treatment with nifedipine-gastrointestinal therapeutic system (GITS) and felodipine-ER compared with enalapril on LV mass relative to the extent of BP control (assessed by 24 h ambulatory BP monitoring) and sympathetic activity (assessed by plasma catecholamine concentrations).


METHODS
Enalapril was started at 10 mg/day, felodipine-ER at 5 mg/day and nifedipine-GITS at 30 mg/day, all once daily. Doses were increased to 20 mg/day, 10 mg/day or 60 mg/day, respectively, if the office BP remained 160/90 mmHg or greater at the end of the dosing interval. Evaluable echocardiograms were obtained for 116 patients at the end of the study (30 weeks of treatment).


RESULTS
On 24 h ambulatory BP monitoring, nifedipine-GITS caused a consistent decrease in BP throughout the 24 h dosing interval, whereas felodipine-ER caused a more marked fall in BP during the day, and enalapril's effects diminished during the night and had disappeared by the morning. Only felodipine-ER significantly increased supine and standing plasma noradrenaline by more than 50% similarly after six, 18, and 30 weeks of treatment. In BP responders (decrease in systolic BP 10 mmHg or greater), enalapril and nifedipine-GITS caused clear decreases in LV mass by 12 to 16 g/m2, whereas felodipine-ER was less effective (decrease by only 6 g/m2, P<0.01 versus enalapril).


CONCLUSIONS
Once-daily dihydropyridines should not be regarded as one homogeneous class and, compared with felodipine-ER, nifedipine-GITS exhibits a better profile regarding 24 h BP control, sympathetic activation and regression of LV mass.
Leenen
Frans H H
FH
University of Ottawa Heart Institute, Canada. fleenen@ottawaheart.ca
Myers
Martin G
MG
Joyner
Campbell D
CD
Toal
Corey B
CB
D000959:Antihypertensive Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects*; D003627:Data Interpretation, Statistical; D004656:Enalapril / Q000008:administration & dosage; D015736:Felodipine / Q000008:administration & dosage; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy*; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage; D009638:Norepinephrine / Q000097:blood; D015990:Placebo Effect; D016037:Single-Blind Method
D000959:Antihypertensive Agents; D015415:Biomarkers; D004656:Enalapril; D009543:Nifedipine; D015736:Felodipine; D009638:Norepinephrine