Does withdrawal of antihypertensive medication increase the risk of cardiovascular events?

The Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure recommends that attempts to discontinue antihypertensive drug therapy be considered after blood pressure (BP) has been controlled for 1 year. However, discontinuation of drug therapy could unmask underlying conditions and precipitate clinical cardiovascular events. The Trial of Nonpharmacologic Interventions in the Elderly (TONE) was a clinical trial of the efficacy of weight loss and/or sodium reduction in controlling BP after withdrawal of drug therapy in patients with a BP<145/85 mm Hg on 1 antihypertensive medication. Of 975 participants, 886 entered the drug withdrawal phase of the trial and 774 were successfully withdrawn from their medications. Thirty-three events (stroke, transient ischemic attack, myocardial infarction, arrhythmia, congestive heart failure, angina, other) occurred between randomization and the onset of drug withdrawal (median time 3.6 months), 57 events occurred either during or after drug withdrawal (14.0 months), and 36 events occurred after resumption of antihypertensive therapy (15.9 months). Event rates per 100 person-years were 5.5, 5.5, and 6.8 for the 3 time periods (p = 0.84) in the nonoverweight group and 7.2, 5.2, and 5.6 (p = 0.08) in the overweight group. The study shows that antihypertensive medication can be safely withdrawn in older persons without clinical evidence of cardiovascular disease who do not have diastolic pressure ≥150/90 mm Hg at withdrawal, providing that good BP control can be maintained with nonpharmacologic therapy.