To the Editor.
—The recent demonstration by Tschollar and Belz1 that treatment of hypertensive crises with sublingual captopril induces a safe and rapid lowering of blood pressure (BP) suggests the need for prospective studies clinically comparing sublingual captopril with nifedipine. In the first comparative study, Hauger-Klevene2 concluded that the hypotensive effect of sublingual nifedipine therapy occurs earlier but has a shorter duration than that of sublingual captopril.In a randomly conducted, doubleblind study, we compared the hypotensive effect of sublingual captopril and nifedipine in 50 consecutive patients with acute hypertensive crises treated in a hospital emergency room. All patients had essential hypertension and a mean BP higher than 130 mm Hg in two different measurements five minutes apart. Equiparable captopril or nifedipine powder capsules for clinical investigation were prepared in the pharmacy department. We administered to each patient an initial capsule, containing either 25 mg of captopril or