Study Author & Study Design Study Population Study Objective Methodology Results
Winchell et al77 A series of open-label, three-period, randomized, crossover studies 1. 24 healthy young subjects (mean age: 25.5 years; range: 19-39 years; 16 males and 8 females) 2. 18 healthy subjects (mean age: 28.7 years; range: 22-40 years; 8 males, 10 females) 3. 12 older subjects (mean age: 71.3 years; range: 65-79 years; 6 males, 6 females)
To investigate the pharmacokinetics and bioavailability of cyclobenzaprine, including the effects of age and hepatic insufficiency
1. Subjects received 5 mg orally or 1.25 mg IV cyclobenzaprine 2. Subjects received a single oral dose of 2.5, 5, or 10 mg cyclobenzaprine on Day 1 then every 8 hours from Days 8 through 14 and a final dose on Day 15 3. Subjects received 5 mg cyclobenzaprine orally three times daily for 7 days and a final dose on the 8th day 3. Cyclobenzaprine plasma concentrations after multiple dosing were significantly higher for the older compared to young subjects - After the first dose, plasma concentration profiles were similar in older and young subjects - Mean accumulation ratio was 7.9 for older subjects compared to 4.3 for young subjects, and mean effective T1/2 was 33.4 h (range: 20.0-53.4 h) in older subjects compared to 18.4 h (range: 9.3-41.3 h) in young subjects
Malhotra et al97 Two randomized double-blind placebo-controlled trials 1. 32 healthy males aged 18-45 2. 16 young men, 16 older men and 16 older women
To examine the effect of age, sex and race on the pharmacokinetics, pharmacodynamics and safety profiles of fesoterodine
Subjects received either 8 mg of fesoterodine extended release or matching placebo with blood samples drawn over 36 h after drug administration
Renal clearance was 28% lower in older men and women than younger men