Swedish Isradipine Study in Hypertension - SWISH


SWISH was a randomized, placebo-controlled, multicenter study of isradipine versus atenolol in patients with essential hypertension.


Isradipine has similar effects to atenolol on control of blood pressure (BP) and quality of life scores.

Study Design

Study Design:

Patients Enrolled: 588
Mean Follow Up: 18 weeks
Mean Patient Age: 52 ± 4 years

Patient Populations:

Men and women with essential hypertension

Primary Endpoints:

BP, side effects, and quality of life score

Secondary Endpoints:

Exercise tolerance

Drug/Procedures Used:

Patients with essential hypertension entered a six-week placebo run-in phase and were then randomized to either continued placebo, isradipine 1.25 mg bid, or atenolol 50 mg qd. If after four weeks of treatment, diastolic BP was >90 mm Hg, dosages were doubled. If after another four weeks, diastolic BP was still >90 mm Hg, both drugs were given in combination (atenolol 100 mg qd plus isradipine 1.25 mg bid). Quality of life was assessed by self-administered questionnaire using a visual analog scale (ASPECT).

Principal Findings:

The study enrolled 588 patients (n=356 for placebo, n=165 for isradipine, and n=191 for atenolol). The mean dosage among the monotherapy patients was 3.6 mg/day for isradipine and 64.4 mg/day for atenolol. As monotherapy, both drugs produced significant decreases in systolic BP (-11.1 mm Hg for isradipine and -18.4 mm Hg for atenolol) and in diastolic BP (-10.6 mm Hg for isradipine and -15.3 mm Hg for atenolol). There were no overall differences between the two compounds in quality of life scores.

Total number of side effects reported were similar for both groups, although cold extremities, fatigue, and vertigo were more common for atenolol, and swollen legs or feet were more common for isradipine. Patients taking isradipine showed no decrease in exercise performance (164 W to 164 W, p=NS), whereas patients in the atenolol arm had a significant drop (146 W to 132 W, p<0.01).


Among patients with essential hypertension, treatment with atenolol as monotherapy was associated with a greater decrease in BP compared to isradipine. Side effects and quality of life scores were similar for both drugs. Atenolol was associated with a significant decrease in exercise performance whereas isradipine was not.


Jern S, Hansson L, Schersten B, et al. Swedish Isradipine Study in Hypertension: evaluation of quality of life, safety, and efficacy. SWISH Group. J Cardiovasc Pharmacol 1991;18(Suppl 3):S7-8.

Clinical Topics: Prevention, Hypertension

Keywords: Isradipine, Quality of Life, Visual Analog Scale, Blood Pressure, Questionnaires, Cold Temperature, Hypertension, Calcium Channel Blockers, Vertigo

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