Vdume 105 Number 5 Brief CommunGcations 665 2. 3. 4. 5. 6. I. 8. 9. 10. Reynolds EW, Vander Ark CR: Quinidine syncope and the delayed repolarization syndromes. Mad Concepts Cardiovasc Dis 45:117, 1976. Koster RW, Wellens HJJ: Quinidine-induced ventricular flutter and fibrillation without digitalis therapy. Am J Car- diol 38:519, 1976. Rubeiz GA, El-Haij M, Touma A: Successful use of external electrical cardioversion in the treatment of ventricular fibril- lation caused by quinidine. Am J Cardiol 16:118, 1965. Bjerkelund C, Skaland K: Kinidin som Arsak til paroxystisk Ventrikkelflimme. Nord Med 77:76, 1967. Kaplinsky E, Yahini JH, Barzilia J, Neufeld HN: Quinidine syncope: Report of a case successfully treated with lidocaine. Chest 62:764, 1972. Cohen IS, Jick H, Cohen SI: Adverse reactions to quinidine in hospitalized patients: Findings based on data from the Boston Collaborative Drug Surveillance Program. Prog Car- diovasc Dis 20:151, 1977. Gaughan CE, Lown B, Lanigan J, Voukydis P, Besser W: Acute oral testing for determining antiarrhythmic drug effi- cacy. I. Quinidine. Am J Cardiol 38:667, 1976. Doering W: Quinidine-digoxin interaction: Pharmacokinet- its, underlying mechanism and clinical implications. N Engl J Med 301:400, 1979. Carliner NH, Crouthamel WG, Fisher ML, Mugmon MA, Vassar DL, Narang PK, Plotnick GD: Quinidine therapy in hospitalized patients with ventricular arrhythmias. AM HEART J 98:706, 1979. Hemodynamic study of nifedipine administration in hypertensive patients Domenico Bonaduce, M.D., Nicola Ferrara, M.D., Mario Petretta, M.D., Enrico Romano, M.D., Maurizio Postiglione, M.D., Franc0 Rengo, M.D., and Mario Condorelli, M.D. Naples, Italy Ca++antagonist drugs are now extensively employed for arterial hypertension management and for angina pecto- ris.1-6 Many authors have assessed the effectiveness of the most important Cat+ antagonist drugs, nifedipine and verapamil,7-gin hypertensive patients; nifedipine was reported to be particularly useful in hypertensive cri- ses.lo,ll However, no double-blind crossover trial has yet been performed to assess the hemodynamic variations following nifedipine administration. Ten male volunteers, 28 to 59 years of age, with mild arterial hypertension (mean systolic blood pressure 175.5 + 2.4 mm Hg, mean diastolic blood pressure 107.5 k 3.7 mm Hg) entered our trial after their informed consent was obtained. Antihypertensive medication was From the Istituto di Patologia Speckle Medica e Metodologia Clinica, II Faculty of Medicine and Surgery, University of Naples. Received for publication June 29, 1981; revision received Aug. 17, 1981; accepted Oct. 10, 1981. Reprint requests: Maurizio Postiglione, M.D., Via Rodolfo Falvo, 20, I 80127, Naples, Italy. Pa (mmHg) 135 -I w Placebo ---a Nhdipine 5.1. &.-.+ Nifedipine P.o. I I I I 0 30 60 120min Fig. 1. Mean arterial pressurevariations (?j,) following nifedipine and placebo administration by sublingual and oral routes. Statistical significanceis obtained comparing the successive final values with starting conditions. s.1. = sublingual; p.o. = oral. *p < 0.001; *‘p < 0.005; tp < 0.01. Table 1. Randomization protocol Patient no. 1st day 2nd day 3rd day 1 Placebo Oral Sublingual 2 Oral Sublingual Placebo 3 Oral Placebo Sublingual 4 Sublingual Placebo Oral 5 Placebo Oral Sublingual 6 Sublingual Oral Placebo 7 Oral Sublingual Placebo 8 Placebo Sublingual Oral 9 Sublingual Oral Placebo 10 Sublingual Placebo Oral discontinued at least 15 days before the trial. Blood pressure (BP) and heart rate (HR) were recorded both in the orthostatic and clinostatic positions for 7 successive days before the trial. During this period one placebo capsule was administered so that patients sensible to placebo treatment could be excluded. One patient was indeed excluded from the trial after the third day on placebobecause his BP returned to normal values without any pharmacologic treatment. The study was then per- formed after overnight fast, at the same hour, following a randomized double-blind scheme. Every morning each patient received two capsules, one orally and one by the sublingual route; while one capsule was always a placebo, the other one was either nifedipine, 10 mg, or placebo, so that on the 3 successive trial days either placebo only or nifedipine plus placebowereadministered. Table I reports the randomization schemewhich enabled us to evaluate both the effectiveness of nifedipine versus placebo and