Effective treatment of hypertension has been shown to reduce cardiovascular disease, morbidity and mortality rates. However, use of antihypertensive medications carries its own risks, particularly in older people, such as adverse drug reactions (ADRs) and drug-drug interactions, and may contribute to polypharmacy.
Researchers from the Cochrane Hypertension Group conducted a review of randomised controlled trials to investigate whether withdrawal of antihypertensive medication is feasible and to evaluate the effects of withdrawal on mortality, cardiovascular outcomes, hypertension and quality of life in older people (>50 years).
Inclusion criteria for the review were met by six parallel-group studies involving 1,073 adults taking antihypertensives for hypertension or for primary prevention of cardiovascular disease, with duration and follow-up ranging from four to 56 weeks.
Primary outcomes (mortality [all-cause and cardiovascular], myocardial infarction [fatal and non-fatal], ADRs and drug withdrawal reactions) were compared for patients whose antihypertensive medication was withdrawn versus those whose medication was continued.
Certainty of the evidence was rated using four levels, with high certainty indicating that the researchers were very confident in the results and very low certainty indicating that they were very uncertain about the results.
Meta-analysis of the studies showed that in the discontinuation group compared with the continuation group the odds ratio for all-cause mortality was 2.08 (95% CI 0.79-5.46; low certainty of evidence), for MI 1.86 (95% CI 0.19-17.98; very low certainty of evidence) and for stroke 1.44 (95% CI 1.82-5.18; low certainty of evidence).
Blood pressure was higher in the continuation group than in the discontinuation group with a mean difference of 9.75mmHg systolic (95% CI 7.33-12.18; low certainty) and 3.50mmHg diastolic (95% CI 1.82-5.18; low certainty) found in favour of continuation.
Discontinuation of antihypertensives had no effect on quality of life or hospitalisations, however, these outcomes were only assessed in one study each.
Meta-analysis for the outcome of ADRs and adverse drug withdrawal reactions was not possible due to differences in how this was reported between studies.
Further research needed
The researchers conclude that the currently available evidence suggests that discontinuing antihypertensive therapy has no effect on all-cause mortality, MI or stroke, compared with continuing therapy. However, there is low or very low certainty in these results, meaning that no firm conclusions can be made about the effects of deprescribing antihypertensives on these outcomes.
They suggest that future research should focus on populations in which there is greatest uncertainty about the benefit:risk ratio for use of antihypertensives (for example, frail and/or older populations and those with polypharmacy) and should measure clinically important outcomes such as falls, quality of life and ADRs.