Lofexidine in the Treatment of Hypertension: A Twice‐Daily versus Once‐Daily Dose Comparison with 24‐Hour Blood Pressure Monitoring

Abstract: Lofexidine, an antihypertensive imidazoline derivative, was given to ten hypertensives on both a twice‐daily and once‐daily regimen, using routine blood pressure measurements and 24‐hour Remler recording. Plasma renin activity and catecholamines were measured. After a dose titration with twice‐daily doses, the total twice‐daily dose was given once daily for two weeks and the drug abruptly withdrawn. Mean placebo blood pressure was 136/104 mm Hg supine. After twice‐daily therapy, this fell to 118/86 mm Hg, and upon conversion to once‐daily therapy, it rose to 126/89 mm Hg. With the Remler recorder, mean 24‐hour blood pressure was 125/89 during the twice‐daily therapy, 133/94 mm Hg during once‐daily therapy, and 142/99 mm Hg on the day after acute withdrawal; i.e., evaluation in all three treatment periods showed a lack of sustained control with both a wide range and high frequency of blood pressure variation. Plasma renin activity and plasma epinephrine and norepinephrine did not change significantly during the study. 1981 American College of Clinical Pharmacology