Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

Sublingual captopril and nifedipine were equally effective and safe for hypertensive emergencies

ACP J Club.1991 Sept-Oct;115:45. doi:10.7326/ACPJC-1991-115-2-045


Source Citation

Angeli P, Chiesa M, Caregaro L, et al. Comparison of sublingual captopril and nifedipine in immediate treatment of hypertensive emergencies. A randomized, single-blind clinical trial. Arch Intern Med. 1991 April;151:678-82.


Abstract

Objective

To compare the effectiveness and safety of sublingual captopril with sublingual nifedipine in the treatment of hypertensive emergencies.

Design

Randomized controlled trial.

Setting

A university-affiliated hospital in Italy.

Patients

22 patients were entered with hypertensive emergencies, defined as diastolic blood pressure (DBP) ≥ 140 mm Hg after 20 minutes of bed rest and symptoms and signs of end-organ damage (angina, transient ischemic attack, hypertensive encephalopathy, or acute heart failure). Patients were excluded if they had pulmonary edema, valvular heart disease, serious disturbance of consciousness, history of myocardial infarction or stroke, or a 10-mm Hg drop in DBP within 20 minutes of placebo administration before study treatment. The study groups were similar for mean age, duration of hypertension, proportion with left ventricular hypertrophy, and serum creatinine and serum urea levels.

Intervention

Patients were randomized to receive either sublingual captopril, 25 mg (n = 10), or sublingual nifedipine, 10 mg (n = 10). Heart rate (HR), blood pressure (BP), symptoms or signs, and adverse effects were assessed 5 times/h for 60 minutes. A drop in DBP of < 10 mm Hg 20 minutes after treatment was considered a nonresponse.

Main outcome measures

Response defined as DBP ≤ 120 mm Hg, mean BP (MBP) < 150 mm Hg, and improvement of symptoms and signs of end-organ failure after 60 minutes.

Main results

Nonresponse was observed in 1 of 10 patients receiving captopril and in 2 of 10 receiving nifedipine. There were 2 and 3 incomplete responders in the captopril and nifedipine groups, respectively. In both groups there were significant drops in SBP and DBP, after 30 minutes for SBP with captopril and after 20 minutes for SBP with nifedipine (all P < 0.05). The maximum drop in SBP and DBP was seen after 50 minutes for both groups. There were no differences in the peak decreases in BP measured: SBP, 55 mm Hg ± 24 (SD) and 44 ± 20; DBP, 29 ± 10 and 39 ± 11; and MBP, 39 ± 14 and 44 ± 17, for captopril and nifedipine, respectively. Heart rate was unaffected by either drug. 3 patients on nifedipine had minor side effects.

Conclusion

Sublingual captopril (25 mg) and sublingual nifedipine (10 mg) were equally effective and safe for the treatment of hypertensive emergencies.

Source of funding: In part, Ministero dell'Universita' e della Ricerca Scientifica e Tenologica.

Address for article reprint: Dr. A. Gatta, Istituto di Medicina Clinica, Via Giustiniani 2, 35100, Padova, Italy.


Commentary

This carefully done study shows that sublingual nifedipine and captopril have equivalent effects in lowering blood pressure in hypertensive emergencies. Readers will want to take careful note of some important features of the study. First, the patients all had hypertensive "emergencies," not "urgencies": they had both severely elevated blood pressures, sustained for 20 minutes of close observation, and acute end-organ damage. Second, only a single dose of nifedipine or captopril was given. The results of the study cannot be applied to patients without acute organ compromise. One must be particularly concerned here with the indiscriminate use of sublingual antihypertensive medication for severely hypertensive patients who have no evidence of impending organ compromise. Such "urgencies" do not require ultra-rapid blood pressure lowering, and sublingual treatments expose these patients to a substantial risk for adverse effects (1).

This study was too small to detect a clinically important difference in the adverse effects of these 2 treatments. There are increasing numbers of reports of adverse effects from sublingual nifedipine (1).

Finally, it is important to note that the ease of use of sublingual treatments for hypertensive emergencies does not obviate the need for intensive care observation of the patient until the crisis has subsided. These patients are in grave danger, and the effects of sublingual treatments are not wholly predictable. If intensive care is available, the control of blood pressure is most precisely obtained from intravenous nitroprusside, despite the nuisance of preparing and administering it. Thus, sublingual treatment is perhaps most appropriate when intensive care monitoring is not immediately available but those supervising care are able to provide very close blood pressure and clinical monitoring.

R. Brian Haynes, MD, PhD
McMaster UniversityHamilton, Ontario, Canada


Reference

1. Wachter RM. Symptomatic hypotension induced by nifedipine in the acute treatment of severe hypertension. Arch Intern Med. 1987;147:556-8.