title: The influence of nifedipine treatment on counter-regulatory mechanisms in essential hypertension.
abstract: The influence of nifedipine treatment on plasma (PV) and extracellular fluid volume (ECV), the ratio of plasma volume to interstitial fluid volume (PV:IF), glomerular filtration rate (GFR), renal clearances of Na+ and K+, plasma concentrations of renin (PRC), angiotensin II (pANG II), aldosterone (pAldo), adrenaline (PA) and noradrenaline (PNA) were studied in 18 consecutive patients with essential hypertension. A 4-week placebo period was followed by a 6-week dose-titration period (period A). Thereafter the dose was kept constant for an additional 6 weeks (period B), the mean dose being 51 mg/day. As compared with placebo, diastolic blood pressure (DBP) decreased from 105 +/- 7 to 93 +/- 9 mmHg at the end of period B. Extracellular fluid volume, PV, and PV:IF were not significantly changed at the end of period A or B, neither in the group as a whole nor in a subgroup, who developed pedal oedema. After 2 weeks on nifedipine, PA as well as PNA increased slightly but returned to control values after 6 weeks of therapy. Plasma renin concentration, pANG II, pAldo and GFR did not change significantly. Renal sodium handling was also unchanged. It is concluded that long-term nifedipine therapy (exceeding 6 weeks) does not lead to activation of counter-regulatory mechanisms such as fluid retention, activation of the renin-angiotensin system and the adrenergic system. Renal function is unaffected by nifedipine.
authors.affiliation: Medical Department C, Glostrup Hospital, Denmark.
authors.forename: N E
authors.initials: NE
authors.lastname: Bruun
authors.forename: H
authors.initials: H
authors.lastname: Ibsen
authors.forename: F
authors.initials: F
authors.lastname: Nielsen
authors.forename: M D
authors.initials: MD
authors.lastname: Nielsen
authors.forename: A G
authors.initials: AG
authors.lastname: Mølbak
authors.forename: O J
authors.initials: OJ
authors.lastname: Hartling
mesh_terms: D000328:Adult; D000368:Aged; D001825:Body Fluid Compartments / Q000187:drug effects; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000627:therapeutic use*; D012084:Renin-Angiotensin System / Q000187:drug effects
chemical_list: D009543:Nifedipine