Blood Pressure Lowering Effect of a New Transdermal Clonidine, M-5041T, during a Resting Period in Subjects with Essential Hypertension.

The blood pressure (BP) lowering effect of a new transdermal clonidine, M-5041T (M) was evaluated in 11 subjects with essential hypertension. After application of a placebo patch for 4 weeks, a patch of M containing clonidine 2 mg (M-2 mg), 4 mg (M-4 mg), 6 mg (M-6 mg), or 8 mg (M-8 mg) was applied for 10 weeks. When an adequate response of office BP [1) areduction in systolic BP (SBP) ≥20 mmHg and diastolic BP (DBP) ≥10 mmHg, 2) areduction in mean BP≥13 mmHg or 3) SBP<150 mmHg and DBP<90 mmHg] was not obtained after 2 weeks of therapy, the dose of clonidine was increased as follows: M-2 mg→M-4 mg→M-6 mg→M-8 mg. BP was measured for 24 hours by a noninvasive automatic device and urine samples for catecholamines were collected from 7am to 10pm (active period) and from 10pm to 7am (resting period) at the end of treatment with placebo (4 weeks) and active drug (10 weeks). The office and ambulatory mean BP was decreased by 12.4% and 4.2%, respectively, by treatment with M. SBP, but not DBP was significantly decreased during the active period by treatment with M. Although a significant BP lowering effect of M was not obtained during the resting period as a whole. An excessive hypotensive episode was observed in one subject. Urinary excretion of norepinephrine was significantly reduced by treatment with Mduring the active period, but not during the resting period. Two subjects complained of itching under the application site of M and discontinued the study.These results suggest that although the BP lowering effect of, M is relatively small during the resting period, an excessive hypotensive episode might occur in some hypertensive patients during this period with treatment with M. In addition, skin reactions might occur during a repeat application of M.