A double-blind, parallel-group multicentre study has been done to compare the antihypertensive properties, effects on serum lipoproteins and adverse effect profiles of diltiazem and metoprolol given as monotherapy to primary hypertensive patients. 128 patients were included from 10 participating centers.
Following a placebo wash-out period of 5 weeks, patients were randomized either to diltiazem or metoprolol treatment according to a forced titration regimen. Each dose was given for a 4-week period in a stepwise regimen. A total of 119 patients, 59 and 60 in the two groups, completed the study.
Supine and standing BPs were reduced in a similar, dose-dependent fashion by diltiazem and metoprolol. In the former supine BP fell from 161/101 to 151/91 mm Hg at the highest dose level. In the latter patients, supine BP at the highest dose level was reduced from 161/102 to 155/94 mm Hg. Target pressures (DBP
90 mm Hg and/or DBP reduction of
10%) were reached in 63% and 48% of the patients, respectively.
HDL-cholesterol was increased in diltiazem-treated patients and decreased in those on metoprolol. Otherwise, serum lipoproteins did not differ significantly between treatments.
The incidence and severity of dose-dependent adverse effects did not differ significantly between treatments, although moderate to distressing side effects were reported more commonly by metoprolol-treated patients. Ankle oedema and breathlessness tended to be more common on diltiazem therapy, while tiredness, increased sweating and sleep disturbances appeared to be experienced more frequently by metoprolol-treated patients.
Thus, when given as monotherapy, the daily dose-ranges for a comperable reduction in BP were 120–360 mg diltiazem and 50–200 mg metoprolol. Within those dose-ranges, the antihypertensive efficacy and the overall incidence of adverse effects did not differ between the treatments. As monotherapies, diltiazem and metoprolol are both suitable for the management of mild to moderate hypertension.
For the Swedish Diltiazem-Metoprolol Multicentre Study GroupThe Swedish Diltiazem-Metoprolol Multicentre Study Group: Thomas Hedner MD PhD, Jan Hedner MD PhD, Bengt Persson MD PhD (Gothenburg); Thomas Thulin MD PhD, Gunnar Persson MD PhD (Lund); Torbjörn Lundström MD (Skövde); Nels Henningsen MD PhD (Malmö); Erik Trell MD PhD, Sven Gustafsson MD (Sunne); Mats Danielson MD PhD (Stockholm); Peter Engfeldt MD PhD, Hans Wahrenberg MD PhD (Huddinge); Bo Hedbäck MD PhD (Oskarshamn); Anders Nilsson MD, Per Katzman MD PhD (Helsingborg); Lennart Andrén MD PhD, Karin Rennblad-Börner MD, Trausti Valdimarsson MD, Inger Wallin MD (Gothenburg); Peter Nilsson-Ehle MD PhD, Ulf Thilén MD, Göran Berglund MD PhD (Lund-Malmö); Carl Dahlöf MD PhD (Gothenburg)
Monitors: Sven-Olle Olsson PhD, Jan Johansson, Eje Berglund, Bo Dahlström (Malmö)
Statisticians: Jerker Ringström BSc, Liz Jergle BSc (Malmö)
Secretaries: Cristina Mardell, Ann-Christine Svensson, Majliz Olsson (Malmö)