Therapy Monotherapy with Nifedipine or Atenolol Controls BP in Most Patients While combination therapy further decreases BP in refractory patients lGP;±STUDJ,V!

The Nifedipine-Atenolol Study Review Committee recruited 459 patients with essential hypertension to participate in a multicentre double-blind trial designed to evaluate the efficacy and tolerability of atenolol and nifedipine alone and in combination. Eligible patients had BPs within the ranges 160/95 and 220/ 120mm Hg « 65 years of age) and 180/100 and 240/130mm Hg (~ 65 years of age). After a 4-week placebo period, patients were randomised to receive either atenolol 50mg once daily (n = 227) or slow release nifedipine 20mg bid (n = 232) for 4 weeks. At week 8, responders maintained their treatment while non-responders maintained drug treatment but at a doubled dose. At week 12, non-responders received a capsule containing nifedipine 20mg + atenolol 50mg once daily for 8 weeks. Compliance of ~ 80% was achieved for 93% of the study group.

Sitting and standing BPs were significantly reduced by both atenolol and nifedipine in the 361 evaluable patients. However, patients receiving nifedipine showed consistently greater reductions in mean systolic pressures than patients receiving atenolol (sitting, p < 0.001; standing p < 0.001). Atenolol treatment resulted in significant reductions in mean sitting and standing heart rates but nifedipine treatment produced no such change. Approximately 60% of patients in each group achieved acceptable BP control. Further significant reductions occurred in all components of BP and heart rate measurements taken in the 149 patients receiving the fixed combination capsule.

121 patients suffered side effects while taking placebo tablets; 11 were withdrawn because of the severity of these reactions. Side effects most commonly associated with nifedipine were flushing, headache, oedema, dizziness and tachycardia or palpitations while those for atenolol included fatigue, lassitude, bradycardia, gastrointestinal upset, peripheral ischaemia and pain. A total of 33 patients withdrew from nifedipine treatment and 15 from atenolol treatment as a result of side effects. Use of a fixed combination of atenolol + nifedipine did not appear to lower the incidence of adverse reactions.

Nifedipine and atenolol are effective both alone and in combination in treating essential hypertension. The authors added that in fixed combination ' ... they may be a useful adjunct to treatment already available for mild to moderate hypertension'. Nlfedlp,ne·Atenolol Study Review Committee British Medical Journal 296 468A72. 13 Feb 1988

6 INPHARMA" 27 February 1988 0156·2703/88/0227-0006/0$01.00/0 © ADIS Press