NEW YORK — Switching the β-blocker that hypertensive patients received to carvedilol led to a significant drop in blood pressure in a series of 17 patients who were not enrolled in a randomized, controlled study.
The finding suggests that “simply switching [from another β-blocker] to carvedilol can help some patients achieve their target blood pressure,” Dr. Nitin Khosla and his associates said in a poster presented at the annual scientific meeting of the American Society of Hypertension.
But the researchers cautioned that the finding needs confirmation in a randomized, controlled trial.
The study involved a review of 1,034 adults with hypertension who were managed at Rush University Medical Center in Chicago. In this group, 17 patients were initially on an antihypertensive regimen that included a β-blocker that was not carvedilol, and then all 17 were subsequently switched to carvedilol and had no other change in their treatment. The average age of the 17 patients was 62 years; 12 (71%) were women, and 9 (53%) were African American. Each patient received an average of 4.6 antihypertensive medications.
The most common β-blocker was metoprolol, in eight patients, followed by atenolol in five and labetalol in four. Patients who began on metoprolol received an average of 106 mg/day and were switched to an average carvedilol dosage of 16 mg b.i.d. Patients who began on atenolol received an average of 75 mg/day and were switched to 12.5 mg/day carvedilol. Those who began on labetalol received an average of 613 mg/day, then changed to an average carvedilol dosage of 21.9 mg b.i.d.
Prior to the drug change, the 17 patients had an average blood pressure of 160/83 mm Hg. By 3–6 weeks after they changed to carvedilol, their average pressure had fallen to 147/73 mm Hg, a statistically significant drop of 13/10 mm Hg.
Before the drug switch, 3 (18%) of the 17 patients had their systolic pressure controlled, compared with 6 patients (35%) after the regimen included carvedilol. Diastolic pressure was at goal levels in 7 patients (41%) before the drug switch and in 15 (88%) after carvedilol was started, said Dr. Khosla, a preventive medicine physician at Rush University Medical Center. The increased level of control for both systolic and diastolic pressure was statistically significant. Heart rate was not significantly affected by the switch to carvedilol, averaging 66 beats per minute before the switch and 70 beats per minute at follow-up.
The study did not receive support from GlaxoSmithKline, the company that markets carvedilol (Coreg).