Pseudoephedrine did not increase blood pressure in hypertension
ACP J Club. 1995 July-Aug;123:10. doi:10.7326/ACPJC-1995-123-1-010
Coates ML, Rembold CM, Farr BM. Does pseudoephedrine increase blood pressure in patients with controlled hypertension? J Fam Pract. 1995 Jan; 40:22-6.
To determine whether therapeutic doses of pseudoephedrine increase blood pressure in adults with controlled hypertension.
Randomized, double-blind, placebo-controlled, crossover trial.
University primary medical care center in the United States.
25 adults (mean age 50 y, 64% women, 56% blacks) with medically controlled hypertension (systolic blood pressure ≤ 140 mm Hg and diastolic blood pressure ≤ 90 mm Hg) for ≥ 6 weeks before enrollment. Exclusion criteria were a history of coronary artery disease or cerebrovascular disease, allergy to pseudoephedrine, current treatment with a monoamine oxidase inhibitor, or potential noncompliance. Follow-up was complete.
Patients received placebo for 1 week and were then assigned to receive pseudoephedrine (n = 13), 60 mg 4 times/d, or placebo (n = 12) during a second week. They received placebo for a third week; during a fourth week, they received the therapy they had not received in the second week. Compliance was measured by pill count.
Main outcome measures
Weekly blood pressure (average of 3 consecutive readings obtained in a seated position), pulse rate, and adverse effects.
Compliance was ≥ 95%. Sample size calculations showed that 21 patients were needed for a 90% power to detect a 5 mm Hg difference in blood pressure with a 2-tailed alpha level of 0.05. Blood pressure and pulse rate did not differ for patients taking either pseudoephedrine or placebo (systolic blood pressure 133 mm Hg for both groups; diastolic blood pressure 82 mm Hg for pseudoephedrine vs 82.5 mm Hg for placebo, and pulse rate 76.8 vs 75.2 beats/min). 2 patients had adverse effects (anxiety and drowsiness) while taking 1 week of pseudoephedrine, and 11 patients had adverse effects during 3 weeks of placebo (3 had headache, 2 had fatigue, and 1 each had anxiety, dizziness, urinary frequency, insomnia, transient sharp chest pain, and back ache).
1 week of pseudoephedrine, 60 mg 4 times/d, did not change systolic or diastolic blood pressure in adults with medically controlled hypertension and no history of cardiovascular or cerebrovascular disease.
Source of funding: Burroughs Wellcome (pseudoephedrine).
For article reprint: Dr. M.L. Coates, Wake Forest University School of Medicine, Department of Family Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1084, USA. FAX 336-716-9126.
The study by Coates and colleagues addresses a common question in primary care. Study participants had well-controlled hypertension, were taking an average of 1.3 antihypertensive agents, and did not have coronary artery or cerebrovascular disease. In designing the study, the investigators ensured sufficient power to detect a true difference between pseudoephedrine and placebo; this issue has not always been addressed in previous studies.
Before deciding that we can now safely use pseudoephedrine in some patients with controlled hypertension, several issues should be considered. First, the authors have provided only limited data about steady-state hemodynamic parameters obtained during weekly measurements. They should have collected information on acute effects, as others have done (1). Second, some classes of antihypertensive agents were not included in this study (e.g., β-blockers). The applicability of these findings to patients taking β-blockers is uncertain, because these patients may experience "unopposed" alpha effects when given pseudoephedrine. Third, the authors do not describe how they selected their participants, and we do not know how well these patients represent all patients with controlled hypertension. Finally, the average weight of the study participants was 90 kg. If dosage affects hemodynamic response, then different findings may be seen in leaner persons.
Although this study adds to the literature on this topic, the common use of pseudoephedrine and the prevalence of hypertension seem to call for a study with more patients and more frequent measurements before a final recommendation is made. In the meantime, we should continue to use pseudoephedrine with caution in patients with hypertension.
Edgar R. Black, MD
University of Rochester School of Medicine and DentistryRochester, New York, USA