Short-term predictors of maintenance of normotension after withdrawal of antihypertensive drugs in the second Australian National Blood Pressure Study (ANBP2)

BACKGROUND: Antihypertensive drug therapy is considered lifelong but in the family practice environment drug cessation may provide an opportunity to attempt nonpharmacologic strategies for blood pressure (BP) control with a clear outcome, maintaining drug-free status. The identification of simple predictors would assist the family physician to select who may or may not have their medication ceased. METHODS: To monitor a drug cessation program in currently treated hypertensive patients in Australian family practice, 25,826 patients aged 65 to 84 years currently receiving antihypertensive medication, were offered drug withdrawal as part of the run-in phase of a large clinical trial. Outcomes investigated were the proportion of patients completing drug withdrawal and maintaining short-term BP control and factors that predicted these patients. RESULTS: A total of 18,993 patients did not enter the withdrawal program; 6291 (92% of those who entered) completed drug withdrawal. In comparison to patients who did not complete drug withdrawal, they were younger and more likely male. A total of 1,228 (18% of those who entered) ceased medication and maintained adequate BP control for 0 to 76 weeks (median, 4 weeks). Cox regression analysis identified lower on therapy systolic and diastolic BP, younger age, type of agent, and monotherapy as predictors of successful drug withdrawal and maintenance of BP control. CONCLUSIONS: Cessation of antihypertensive drug therapy is possible in a substantial proportion (18%) of patients attending family practice who are willing to do so and is most successful in those who are younger with BP controlled on monotherapy. Where this strategy is initiated, use of such predictors, effective behavioral change, and systematic follow-up is recommended.