The aim of this study was to establish whether bumetanide can abort an acute attack of weakness in patients with HypoPP. This was a randomised, double-blind, cross-over, placebo-controlled phase II clinical trial. Focal attack of weakness was induced by isometric exercise of ADM followed by rest (McManis protocol). Participants had two study visits and received either placebo or 2 mg bumetanide at attack onset (defined as 40 % decrement in the abductor digiti minimi CMAP amplitude from peak). CMAP measurements assessed attack severity and duration. Nine participants completed both visits. CMAP percentage of peak amplitudes in the bumetanide (40.6 %) versus placebo (34.9 %) group at 1hr following treatment did not differ significantly (estimated effect difference 5.9 % (95 % CI: (-5.7 %; 17.5 %), p = 0.27, primary outcome). CMAP amplitudes assessed by the area under the curve for early (0-2hr post-treatment) and late (2-4 h post-treatment) efficacy were not statistically different between bumetanide and placebo (early effect estimate 0.043, p = 0.3; late effect estimate 0.085, p = 0.1). Two participants recovered from the attack following bumetanide intake; none recovered following placebo. Bumetanide was well tolerated but not efficacious to rescue a focal attack in an immobilised hand in the majority of patients, although data supports further studies of this agent.

暂无摘要。

Single-and multiple-dose pharmacokinetics and safety were investigated in this phase 1 study of dichlorphenamide, a carbonic anhydrase inhibitor approved in the United States for treatment of primary periodic paralysis. Dichlorphenamide was administered to 6 cohorts (n = 6 each) of healthy adults. Cohorts A through E received single doses of 25-400 mg followed by 50-800 mg/day in divided doses for 10 total doses. Cohort F (safety analysis only) received up to 28 titrated doses from 100-800 mg/day. Plasma for pharmacokinetics sampling was obtained predose and up to 48 hours postdose. Twenty-five of 36 enrolled subjects completed. Median time to maximum plasma concentration ranged from 1.5-3 hours, and mean half-life from 32-68 hours. Mean area under the concentration-time curve from time 0 to tau (length of the dosing interval estimated using the trapezoidal method) and maximum observed plasma concentration increased dose-proportionally after multiple doses. The incidence and severity of adverse events (AEs) were dose-related, with at least one mild AE reported among 17%, 17%, and 67% of patients in cohorts A, B, and C, respectively; and at least one mild-to-moderate AE among 100% of subjects in cohorts D, E, and F. One serious AE of rash was reported in cohort F. Eleven subjects discontinued; 10 due to AEs at 400 or 800 mg/day (cohorts E and F), including 100% of cohort F. Hypokalemia contributed to 5 of 6 discontinuations in cohort F (all 800 mg/day).

OBJECTIVE: There is paucity of reports on thyrotoxic periodic paralysis (TPP) from India. We report the patients with TPP and compare them with idiopathic hypokalemic periodic paralysis (IHPP).
METHODS: Patients with hypokalemic periodic paralysis (HPP) treated during the past 11 years were evaluated retrospectively. Their demographic parameters, family history, clinical features, precipitating factors, severity of weakness, laboratory parameters and rapidity of recovery were recorded. The demographic, clinical and laboratory parameters of TPP and IHPP were compared.
RESULTS: During the study period, we managed 52 patients with HPP; nine (17.3%) of whom had TPP and 27 (52%) had IHPP. The demographic, precipitating factors, number of attacks and severity of limb weakness were similar between the TPP and IHPP groups, except in the IHPP group, bulbar weakness was present in four and respiratory paralysis in six, needing artificial ventilation in two patients. Serum potassium was significantly lower in TPP (2.21 ± 0.49) compared with IHPP (2.67 ± 0.59, P = 0.04). Four patients with TPP had subclinical thyrotoxicosis and two had subclinical hyperthyroidism. Rebound hyperkalemia occurred in both TPP and IHPP (three versus eight patients). The recovery was faster in IHPP (26.7 ± 15.4 h) compared with TPP (34.0 ± 14.0 h), but was statistically insignificant.
CONCLUSIONS: TPP constitutes 17.3% of HPP, and absence of clinical features of thyrotoxicosis and subclinical hyperthyroidism in TPP is not uncommon. Clinical features, demographic profile and rebound hyperkalemia are similar in both TPP and IHPP. The serum potassium level is significantly low in the TPP compared with the IHPP group.