Clinical Drug Investigation

, Volume 22, Issue 11, pp 719–729

Metoprolol Succinate SR plus Hydrochlorothiazide (Beloc-Zok® Comp) in Patients with Essential Hypertension in General Practice

A Prospective, Observational Trial in 14 964 Patients
  • S. K. Hildemann
  • H. Fischer
  • D. Pittrow
  • V. Bohlscheid
Original Research Article

DOI: 10.2165/00044011-200222110-00001

Cite this article as:
Hildemann, S.K., Fischer, H., Pittrow, D. et al. Clin. Drug Investig. (2002) 22: 719. doi:10.2165/00044011-200222110-00001



Low-dose combination treatment for patients with essential hypertension has received growing interest since the introduction of recent guidelines. We investigated the efficacy and tolerability of a fixed low-dose combination of once-daily metoprolol succinate 95mg (slow-release Zok) plus hydrochlorothiazide (HCTZ) 12.5mg in daily practice.


This was an open-label, multicentre, prospective, observational phase IV study in 14 964 patients with hypertension at 2 808 general practitioners’ offices throughout Germany.

Main outcome measure

Decrease in systolic and diastolic blood pressure (BP) and heart rate from baseline after 8 weeks, and analysis of adverse events.


54% of the patients were male; the mean age was 57 years (range 16 to 99 years), and the mean body mass index was 27 +- 4 kg/m2. Of the study patients, 74.9% had essential hypertension only, and 23.7% also had coronary artery disease. The drug combination reduced mean systolic and diastolic BP by 24.5/13.6mm Hg from baseline (166.7/97.3mm Hg) after 8 weeks (p < 0.0001 for systolic and diastolic BP); 92.2% of patients had a ≥10mm Hg reduction in systolic BP. Mean heart rate was reduced by 10.2 beats/min (from 81.4 beats/min; p < 0.0001). The BP-lowering effect was consistent in patients who received metoprolol succinate/HCTZ as first-line treatment and those who received it in addition to other antihypertensive therapies. Tolerability of the combination was excellent: 98.6% of patients remained free of adverse events during the study.


This 8-week non-interventional study carried out under daily routine practice conditions in a large heterogeneous sample of patients with multiple concomitant diseases and taking various co-medications confirmed the efficacy and tolerability of the metoprolol succinate/HCTZ combination in the treatment of patients with essential hypertension.

Copyright information

© Adis International Limited 2002

Authors and Affiliations

  • S. K. Hildemann
    • 1
  • H. Fischer
    • 2
  • D. Pittrow
    • 3
  • V. Bohlscheid
    • 4
  1. 1.Pharmacia GmbHErlangenGermany
  2. 2.Medical Department IIKrankenhaus VincentinumRuhpoldingGermany
  3. 3.Department of Clinical Pharmacology, Medical FacultyUniversity of DresdenDresdenGermany
  4. 4.Medical Department IIIDietrich Bonhoeffer KlinikumNeubrandenburgGermany