Effect of telmisartan/hydrochlorothiazide combination versus nifedipine GITS on ambulatory blood pressure and sympathetic activation.
BACKGROUND
This study compares the effects of telmisartan hydrochlorothiazide (HCTZ) combination versus nifedipine GITS on ambulatory blood pressure (BP) and sympathetic activity, in patients with mild-to-moderate hypertension.


METHODS
One hundred twenty-four outpatients with sitting diastolic BP > or =95 mmHg and <110 mm Hg were randomized to telmisartan 80 mg/HCTZ 12.5 mg daily (n = 62) or nifedipine GITS 60 mg daily (n = 62) for 12 weeks, according to a prospective, open-label, blind end point, parallel-group design. At the end of a 2-week washout period and after 12 weeks of active treatment, 24-h noninvasive ambulatory BP monitoring (ABPM) was performed, clinic BP and heart rate were measured, and plasma norepinephrine and cardiovascular responses to mental stress induced by the color word test were assessed.


RESULTS
Both treatments reduced ambulatory and clinic BP. However, the drug combination had an antihypertensive efficacy significantly greater than nifedipine GITS, as shown by the 24-h (P < .001), daytime (P < .001), and night-time (P < .01) ambulatory BP monitoring values, as well as by the clinic BP at trough (P < .05). The trough-to-peak ratio was similar, but the smoothness index was significantly higher with the combination for both systolic and diastolic BP (P < .05). A significant increase in plasma norepinephrine levels in resting conditions was observed with nifedipine GITS (+20%) but not with telmisartan/HCTZ combination. The color word test produced a greater increase in plasma norepinephrine and heart rate values in the patients treated with nifedipine GITS than in those treated with the combination.


CONCLUSIONS
These results suggest that the telmisartan 80 mg/HCTZ 12.5 mg combination provided a more sustained and homogeneous BP control than nifedipine GITS 60 mg, without producing sympathetic activation.
Fogari
Roberto
R
Department of Internal Medicine and Therapeutics, Clinica Medica II IRCCS Policlinico S.Matteo, University of Pavia, Pavia, Italy. r.fogari@smatteo.pv.it
Preti
Paola
P
Zoppi
Annalisa
A
Corradi
Luca
L
Pasotti
Carlo
C
Rinaldi
Andrea
A
Mugellini
Amedeo
A
D000328:Adult; D000368:Aged; D001562:Benzimidazoles / Q000494:pharmacology* / Q000627:therapeutic use; D001565:Benzoates / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D004338:Drug Combinations; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006852:Hydrochlorothiazide / Q000494:pharmacology* / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000494:pharmacology* / Q000627:therapeutic use; D009638:Norepinephrine / Q000097:blood; D011446:Prospective Studies; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000502:physiology; D000077333:Telmisartan
D001562:Benzimidazoles; D001565:Benzoates; D004338:Drug Combinations; C436283:telmisartan, hydrochlorothiazide drug combination; D006852:Hydrochlorothiazide; D009543:Nifedipine; D000077333:Telmisartan; D009638:Norepinephrine