How long will I have to take blood pressure medicine? - Chlorthalidone

According to the European Society of Cardiology (ESC) and the European Society of Hypertension (ESH), antihypertensive drug treatment should be continued for life as hypertension usually returns when treatment is stopped.¹ Patients may be able to lower the dosage and number of medicines with increasing healthy lifestyle changes such as exercise and weight loss.¹ These reductions should be made gradually, with a clinician, and should be checked regularly because of the risk of reappearance of hypertension.¹

Evidence shows that antihypertensive treatment significantly lowers blood pressure, and reduces the chances of complications associated with hypertension. ^2-10  Discontinuing medication therefore leads to increased risk of adverse outcomes. Breekveldt-Postma et al. studied the effects of discontinuing hypertension medication on cardiovascular outcomes.¹¹ The study monitored 77,193 men and women ages 18 and older who were new users of antihypertensives (AHT).¹¹ Users were considered new if they had not had diuretics, beta-blockers, calcium channel blockers, ARBs, and any other antihypertensives dispensed for at least one year before the index date.¹¹ New users were excluded from the study if they had taken nitrates in the year prior to the start of taking an AHT or if there was a history of cardiovascular disease.¹¹ At year one, 45% of patients discontinued AHT treatment and at year two, 55% of patients discontinued treatment.¹¹ There was a 15% increased risk for an acute myocardial infarction (MI) [RR 1.15; 95% CI 1.00-1.33], and a 28% increased risk for a stroke amongst patients who discontinued AHT treatment [RR 1.28; 95% CI 1.15-1.45].¹¹ These findings reiterate the importance of continued use of antihypertensive medications.

Stamler et al. evaluated whether patients with controlled hypertension could discontinue antihypertensive drug therapy using nutritional means to control blood pressure.¹² Participants were men and women, 35 years of age and older with controlled blood pressure on antihypertensive treatment (defined as a diastolic blood pressure <95 mm Hg for one year and <90 mm Hg at two visits prior to randomization).¹² To be eligible participants had to meet the following criteria: a controlled blood pressure with drugs no higher than step 3 drug classification (step 1 – diuretic; step 2 – addition of reserpine, alphamethyldopa, or propranolol hydrochloride, step 3 – addition of hydralazine hydrochloride, prazosin hydrochloride, or clonidine hydrochloride, step 4 – guanethidine monosulfate in addition to step 1 and step 2 drugs), be 10% to 49% overweight and/or have a sodium intake greater than 2800 mg/d, have no major cardiovascular complications, have no other major diseases, and have no known history of an alcohol use disorder.¹²

One hundred eighty nine patients were randomly assigned to one of three groups: group 1 – discontinuation of drug therapy and reduce overweight, excess salt, and alcohol; group 2 – discontinuation of drug therapy with no nutritional program; and group 3 – continue drug therapy with no nutritional program.¹² At baseline, the mean systolic blood pressure for groups 1, 2 and 3 were 122.4 mm Hg, 117.6 mm Hg, and 119.2 mm Hg, respectively.¹²  In groups 1 and 2, patients resumed drug therapy if blood pressure rose to hypertensive levels (defined as diastolic BP ≥115 mm Hg or an average diastolic BP >90 mm Hg at visits one to two weeks apart).¹² At year four, 61% of group 1 subjects were unable to control their blood pressure with nutritional intervention alone, and 54% of subjects were placed back on drug therapy.¹² The majority of group 2, 93% of participants, required resumption of drug therapy, while only 5% were able to achieve a controlled BP without resuming therapy (p<0.001).¹² In group 1, among those that did not receive medication, average diastolic blood pressure rose by 4.6 mm Hg, and average systolic rose by 10.6 mm Hg.¹² Amongst the 5% of participants in group 2 who did not receive medication, the average increase in diastolic and systolic pressure was 1.7 mm Hg and 6.7 mm Hg, respectively.¹² Group 3, which continued drug therapy, had an increase of 1 mm Hg in diastolic blood pressure and 2.5 mm Hg increase in systolic blood pressure (p<0.001).¹²

By year four subjects in group 1 achieved a mean weight loss of 1.8 kg (4 lb.) along with a 36% decrease in daily urinary sodium output.¹² Group 2, on the other hand, gained an average of 1.8 kg (4 lb.) and daily urinary sodium output increased 13%.¹² Although 39% participants in group 1 were able to remain normotensive, the average diastolic and systolic blood pressure in group 1 was 3.6 mm Hg and 8.1 mm Hg higher than subjects in group 3.¹² The results of this study suggest that intensive lifestyle modification can decrease the need for medication management of blood pressure in some people with controlled hypertension. The outcome of group 2 (93% rose to hypertensive level) ¹² illustrates what may occur when patients stop drug therapy without an intensive lifestyle intervention. 

The Treatment of Mild Hypertension Study, a randomized, double-blind, placebo controlled clinical trial of six antihypertensive treatments, also addressed the use of nutritional means to control blood pressure.¹³ Participants were men and women ages 45 to 69 years with diastolic blood pressure (DBP) < 100 mm Hg.¹³ All six groups were given a nutritional intervention to reduce weight, dietary sodium intake, alcohol intake, and increase physical activity.¹³ One of the groups was given placebo (n=234) while the remaining five were given chlorthalidone (n=136), acebutolol (n=132), doxazosin mesylate (n=134), amlodipine maleate (n=131), or enalapril maleate (n=135).¹³ If a placebo participant had DBP ≥95 mm Hg on three successive visits or ≥105 mm Hg at a single visit, drug treatment was started (chlorthalidone added first followed by enalapril if needed).¹³ By year four of the study, 67% of the placebo group maintained DBP less than or equal to 95 mm Hg through nutritional intervention alone.¹³ The ability of the placebo group to remain off antihypertensives offers additional evidence that intensive lifestyle modification alone can control blood pressure in some individuals with hypertension (DBP <100 mm Hg).

Similarly, a three-arm, randomized, 18-month trial by Elmer et al. found that for people with stage 1 hypertension, lifestyle modification alone may lower blood pressure.¹⁴ Participants (men and women ages 25 and older with prehypertension or stage 1 hypertension) were randomized to one of three groups: the advice group, the established group, or the established plus DASH group.¹⁴ Advice group participants received advice to reduce weight, follow a reduced sodium diet, engage in regular moderate-intensity physical activity, and eat a healthy diet including the DASH diet (high in fruits, vegetables, and low-fat dairy products and low in saturated fat, total fat, and cholesterol).¹⁴ Participants in the established and the established plus DASH group were given a weight loss goal of at least 6.8 kg (15 lb.), at least 180 minutes of moderate-intensity physical activity per week, daily dietary sodium intake ≤100 mmol, and a daily alcohol consumption limit of 30 mL (1 oz.) for men, 15 mL (0.5 oz.) for women.¹⁴ Establish plus DASH group participants were instructed to reduce saturated and total fat consumption and were given the following daily intake goals: 9-12 servings of fruits or vegetables, 2-3 servings of low-fat dairy.¹⁴ After 18 months, the percent of participants with hypertension decreased to 63% in the advice group, 40% in the established group, and 38% in the established plus DASH group.¹⁴ Thus, each of the lifestyle interventions led to blood pressure reduction in some patients with the most intensive intervention group having the largest number of patients who were able to achieve normal blood pressure.

^References

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11. Breekveldt-Postma NS, Penning-van Beest FJ, Siiskonen SJ, et al. The effect of discontinuation of antihypertensives on the risk of acute myocardial infarction and stroke. Current medical research and opinion. 2008;24(1):121-127.
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