Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Effectiveness of Nifedipine 20mg Prolonged Action Tablet (Adalat PA 20) in the Management of Hypertension in General Practice


Patients with mild to moderate hypertension while on therapy (33%) or those with moderate to severe hypertension while receiving no treatment (67%) were entered into an 8-week programme. Nifedipine 20mg prolonged action tablets were administered as 1 tablet twice daily for a minimum of 4 weeks, after which the dose was doubled if blood pressure measurements in the general practitioner's office warranted it.

The blood pressure fell from 169/102mm Hg initially to 144/85mm Hg after 8 weeks, when 88% of patients were receiving 1 tablet twice daily. Approximately 90% of patients, whether on combination therapy or taking nifedipine alone, reached a goal of 90mm Hg or less in 4 weeks. The heart rate did not change significantly from its initial value of 77 beats/min at any of the 2-weekly visits during the programme.

The 4 most common adverse experiences peaked at week 2 and, with the exception of peripheral oedema, declined thereafter.

This is a preview of subscription content, log in to check access.


  1. Bühler FR. Antihypertensive treatment according to age, plasma renin and race. Drugs 35: 495–503, 1988

  2. Chalmers JP, Smith SA, Wing LMH. Hypertension in the elderly: antagonists. Journal of Cardiovascular Pharmacology 12(Suppl. 8): S147–S155, 1988

  3. Duffy J, Macdonald G. The antihypertensive efficacy of nifedipine alone and in combination in general practice. Current Medical Research and Opinion 10: 566–572, 1987

  4. Lau K, Eby B. The role of calcium in genetic hypertension. Hypertension 7: 657–667, 1985

  5. Parker D, Liu K, Dyer AR, Giumetti D, Liao Y, et al. A comparison of the random-zero and standard mercury sphygmomanometers. Hypertension 11: 269–272, 1988

  6. Robinson BF. Altered calcium handling as a cause of primary hypertension. Journal of Hypertension 2: 453–460, 1984

  7. Sorkin EM, Clissold SP, Brogden RN. Nifedipine: a review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy, in ischaemic heart disease, hypertension and related cardiovascular disorders. Drugs 30: 182–274, 1985

  8. Tifft CP. Are the days of the sphygmomanometer past? Archives of Internal Medicine 148: 518–519, 1988

  9. Ziegler WJ, Bach D. Efficacy of nifedipine retard tablets as antihypertensive treatment in interactions with concomitant medication: results of a prospective multicentre study in Switzerland. In Lichtlen PR (Ed), pp. 329–334, 6th International Adalat Symposium, Excerpta Medica, Amsterdam, 1986

Download references

Author information

Additional information

Consultants to the group were: Colin C. Barnes, Hamilton; Peter Bolli, S1. John’s; Ellen D. Burgess, Calgary; George H. Changfoot, New Westminster; John Cobby, Etobicoke; Satya P. Handa, Saint John; Marc Houde, Montreal; Louis E. Laplante, Montreal; Evan J. Monkman, Toronto; S. Brian Penner, Winnipeg; Eli Z. Rabin, Ottawa; Laurie R. Silverberg, Toronto; Clair C. Williams, Toronto; George G. Wu, Mississauga.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Effectiveness of Nifedipine 20mg Prolonged Action Tablet (Adalat PA 20) in the Management of Hypertension in General Practice. Drug Invest 1, 24–28 (1989).

Download citation