Aims of combination therapy--improved quality of life or better blood pressure control?
The combination of nifedipine and atenolol must be evaluated in terms of risks and benefits to the hypertensive patient. Disadvantages with single-agent therapy justify trials of combination regimens. beta-Blockers may be unacceptable to some patients because of gastrointestinal upset, musculoskeletal symptoms, tiredness, malaise, insomnia, depression or confusion, sweating, breathlessness or cold extremities. The side effect profile varies from patient to patient and between different beta-blockers. Calcium antagonists also have characteristic side effects, including severe headaches, flushing and oedema, tachycardia and possibly worrying palpitations, and polyuria. Combining a calcium antagonist and a beta-blocker can reduce some side effects; for example, tachycardia is offset by addition of beta-blocker to calcium antagonist therapy, and beta-blocker-induced cold extremities may be reversed with a drug such as nifedipine. Moreover, the antihypertensive efficacy is increased, which is useful in previously resistant patients. However, an excessive fall in blood pressure is a possible adverse effect of the combination. There is also the possibility of precipitating heart failure in patients with cardiomegaly and severely compromised left ventricular function. The combination of nifedipine and atenolol was evaluated in 25 patients in a randomised, crossover trial following a month's treatment with atenolol 50mg twice daily. Patients received either atenolol 50mg twice daily alone, or atenolol 50mg twice daily with sustained release nifedipine 20mg or 40mg twice daily, or placebo twice daily during three 4-week treatment periods. Additional antihypertensive benefit was obtained by addition of the low dose of nifedipine compared with atenolol alone, but no further advantage was obtained with the higher nifedipine dose.(ABSTRACT TRUNCATED AT 400 WORDS)
Maclean
D
D
Department of Clinical Pharmacology, Ninewells Hospital, Dundee.
D001262:Atenolol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D003692:Delayed-Action Preparations; D004359:Drug Therapy, Combination; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D009543:Nifedipine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D003692:Delayed-Action Preparations; D001262:Atenolol; D009543:Nifedipine