Jain A K, Hiremath A, Michael R, Ryan J R, McMahon F G
Clin Pharmacol Ther. 1985 Mar;37(3):271-6. doi: 10.1038/clpt.1985.39.
Guanfacine, 1 to 3 mg/day, and clonidine, 0.1 to 0.3 mg twice a day, were compared in a 24-week double-blind, randomized, parallel study of 42 patients with hypertension that was inadequately treated by chlorthalidone, 25 mg/day. Mean reduction of blood pressure was 18/9 mm Hg after guanfacine and 14/8 mm Hg after clonidine. To determine the incidence of rebound hypertension, subjects were hospitalized for 7 days during chlorthalidone therapy for collection of baseline data and once again immediately after abrupt withdrawal of the alpha-agonist after 24 weeks of dosing. Although blood pressure and heart rate rose significantly in both groups, the changes after clonidine withdrawal were greater and occurred earlier (day 2) than those after guanfacine withdrawal (day 4). Forty percent of the subjects receiving guanfacine and 64% of subjects receiving clonidine had diastolic blood pressure elevations greater than or equal to 10 mm Hg from baseline. There were increases in urinary norepinephrine levels in both groups after drug withdrawal, but these correlated poorly with blood pressure rise. Side effects after guanfacine were much the same as those after clonidine. Guanfacine taken once a day provides an effective and safe alternative to clonidine in the management of essential hypertension.
在一项为期24周的双盲、随机、平行研究中，对42例使用氢氯噻嗪（每日25mg）治疗效果不佳的高血压患者，比较了胍法辛（每日1至3mg）和可乐定（每日0.1至0.3mg，分两次服用）的疗效。服用胍法辛后平均血压降低18/9mmHg，服用可乐定后平均血压降低14/8mmHg。为确定反跳性高血压的发生率，受试者在氢氯噻嗪治疗期间住院7天以收集基线数据，并在给药24周后突然停用α受体激动剂后立即再次住院。虽然两组患者的血压和心率均显著升高，但可乐定停药后的变化更大，且发生时间更早（第2天），而胍法辛停药后的变化（第4天）则较晚。接受胍法辛治疗的受试者中有40%，接受可乐定治疗的受试者中有64%，其舒张压较基线升高≥10mmHg。停药后两组患者尿去甲肾上腺素水平均升高，但这些变化与血压升高的相关性较差。胍法辛的副作用与可乐定的副作用大致相同。在原发性高血压的治疗中，每日服用一次胍法辛为可乐定提供了一种有效且安全的替代方案。
