silodosin and Hypotension

The objectives of the study were to assess the safety and pharmacokinetics of silodosin capsules in 82 healthy male Chinese subjects. To evaluate the safety after single-dosing escalation, 40 subjects were equally divided into 4 groups (2, 4, 8, 12 mg) by a randomized, double-blind and placebo-controlled design. To assess the pharmacokinetics after single-dosing, 30 subjects were equally divided into 3 groups (4, 8, 12 mg). To assess the safety and pharmacokinetics via multiple-dosing, 12 subjects were included as a group (4 mg once daily at day 1 and day 7; 4 mg twice daily at day 2 through day 6). The safety observations showed that mild adverse events, including postural hypotension, dizziness, and headache, were observed. After single-dosing at doses of 4, 8, and 12 mg, the mean area under the concentration-time curve from 0 to 36 h (AUC(0-36)) values were 136.82±46.38, 270.17±54.66, and 474.63±108.50 µg/l·h and the mean maximal silodosin concentration in plasma (C(max)) values were 26.70±7.48, 48.47±12.35, and 94.07±22.59 µg/l, respectively. After multiple-dosing, the C(max) value at day 7 was 33.84±19.54 µg/l, and the AUC(0-24) value at day 7 was 193.19±68.96 µg/l·h. The accumulation ratio of the AUC value was 1.55 by comparing the multiple-dosing with the single-dosing. It is concluded that silodosin is safe and tolerated in healthy Chinese male subjects at the dosing levels used in this study. The mean C(max) and AUC values of silodosin increased proportionally with dose escalation, showing characteristics of linear pharmacokinetics.

Topics: Adrenergic Antagonists; Adult; Area Under Curve; Asian People; Double-Blind Method; Headache; Humans; Hypotension; Indoles; Male; Receptors, Adrenergic, alpha-1; Vertigo; Young Adult

Do men starting treatment with prostate-specific α antagonists have increased risk of fall and fracture?. Administrative datasets from the province of Ontario, Canada, that contain patient level data were used to generate a cohort of 147,084 men aged ≥ 66 years who filled their first outpatient prescription for prostate-specific α antagonists tamsulosin, alfuzosin, or silodosin between June 2003 and December 2013 (exposed men) plus an equal sized cohort matched 1:1 (using a propensity score model) who did not initiate α antagonist therapy. The primary outcome was a hospital emergency room visit or inpatient admission for a fall or fracture in the 90 days after exposure.. The men exposed to prostate-specific α antagonist had significantly increased risks of falling (odds ratio 1.14 (95% CI 1.07 to 1.21), absolute risk increase 0.17% (0.08 to 0.25%)) and of sustaining a fracture (odds ratio 1.16 (1.04 to 1.29), absolute risk increase 0.06% (0.02 to 0.11%)) compared with the unexposed cohort. This increased risk was not observed in the period before α antagonist use. Secondary outcomes of hypotension and head trauma were also significantly increased in the exposed cohort (odds ratios 1.80 (1.59 to 2.03) and 1.15 (1.04 to 1.27) respectively). The two cohorts were similar across 98 different covariates including demographics, comorbid conditions, medication use, healthcare use, and prior medical investigation. Potential unmeasured confounders, such as physical deconditioning, mobility impairment, and situational risk factors, may exist. The data used to identify the primary outcomes had limited sensitivity, so the absolute risks of the outcomes are probably underestimates. The study only included men ≥ 66 years old, and 84% of exposed men were prescribed tamsulosin, so results may not be generalizable to younger men, and there may not be statistical power to show small differences in outcomes between the drugs.. Prostate-specific α antagonists are associated with a small but significant increased risk of fall, fracture, and head trauma, probably as a result of induced hypotension.. This project was conducted at the Institute for Clinical Evaluative Sciences (ICES) Western Site through the Kidney, Dialysis, and Transplantation (KDT) research program. BW has received a research grant from Astellas, and L-AF does consultancy for Amgen.

Topics: Accidental Falls; Adrenergic alpha-1 Receptor Antagonists; Aged; Canada; Craniocerebral Trauma; Fractures, Bone; Humans; Hypotension; Indoles; Male; Outcome Assessment, Health Care; Prostate; Prostatic Hyperplasia; Quinazolines; Retrospective Studies; Risk Factors; Sulfonamides; Tamsulosin