14 THERAPY

Optimising antihypertensive therapy: age, race and QOL are important factors

Despite the profusion of antihypertensive therapies available, only a small percentage of patients are receiving adequate treatment, says Dr S Oparil from the University of Alabama School of Medicinel. In the US, physicians have a choice of 68 drugs from 8 drug classes, as well as various lifestyle modifications. So, how do they optimise their patient's treatment?

Two US studies have come up with some startling insights into antihypertensive therapy. The Department of Veterans' Affairs Cooperative Study Group on Antihypertensive Agents has shown that the patient's race and, to a lesser extent, age influence response to various single­drug therapies2• And the Quality-of-Life Hypertension Study Group has determined that drug-induced changes in quality of life can differ between drugs of the same class3•

Race, age and response For the first time, agents from all 6 major

antihypertensive drug classes were directly compared in a group of 1292 hypertensive men, which included large numbers of both Blacks and Whites, in addition to the middle-aged and elderlyl. The data showed that race and age were powerful determinants of response and should be considered in the initial choice of agent2•

Efficacy of antihypertensive therapies

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With the primary study endpoint defmed as a diastolic BP < 95mm Hg after 12 months' maintenance therapy, the trial showed significant differences between the study drugs (atenolol,

10 Apr 1993 INPHARMA*

captopril, clonidine, diltiazem, hydrochloro­thiazide, prazosin). Overall, diltiazem was associated with a small but significant advantage in achieving BP control; 59% of patients responded compared with 42-51 % of patients in the other 5 active treatment groups. All treatments were superior to placebo (25%).

When considering both race and age, diltiazem was most effective for both younger « 60 years) and older Blacks (~60 years), producing a response rate of 64%. And while all drugs were similarly effective for older Whites, atenolol, clonidine and diltiazem were most effective in reducing diastolic BP in younger Whites. These results are summarised in the 4 figures .

SimDar but not the same Although captopril and enalapril are

indistinguishable regarding efficacy and safety, captopril is associated with a 'more favourable change' in quality of life than enalapril3, I.

Calibration analysis suggested that the difference between the 2 agents was 'clinically meaningful'.

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Change In overall quality of life

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In the Quality-of-Life Hypertension Study, captopril's quality of life profile was consistently better, with positive changes in overall quality of life, general health status, vitality, sleep, and behavioural or emotional controP. The difference was more pronounced when patients were categorised by quality of life at baseline. In this trial, the positive effects of ACE inhibitor therapy were predominantly seen in patients with a low baseline quality of life; patients receiving either ACE inhibitor remained stable or improved. Contrasting with this, patients with high baseline quality of life scores remained stable on captopril but worsened on enalapril [see figure].

The study involved 379 men with mild to moderate hypertension treated with either captopril or enalapril, with or without hydrochlorothiazide.

1. Oparil S. Antihypertensive therapy - Efficacy and quality of life. New England Journal of Medicine 328: 959-961,1 Apr 1993 2. Materson BJ, et aI. Single-drug therapy for hypertension in men. A comparison of six antihypertensive agents with placebo. 3. Testa MA, et aI. QUality of life and antihypertensive thempy in men. A comparison of captopriJ with enalapril. New England JournaI of Medicine 328: 907-913, I Apr 1993

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ISSN 0156-2703/93/0410-0014/$1.00° Adls International Ltd