CLARINEX-D 12 HOUR Extended Release Tablets (desloratadine/pseudoephedrine sulfate)(九)
d Hispanics (2%, n=1063). The median exposure (AUC) to desloratadine in the poor metabolizers was approximately 6-fold greater than in the subjects who are not poor metabolizers. Subjects who are poor metabolizers of desloratadine cannot be prospectively identified and will be exposed to higher levels of desloratadine following dosing with the recommended dose of desloratadine. In multidose clinical safety studies, where metabolizer status was prospectively identified, a total of 94 poor metabolizers and 123 normal metabolizers were enrolled and treated with CLARINEX Syrup for 15 to 35 days. In these studies, no overall differences in safety were observed between poor metabolizers and normal metabolizers. Although not seen in these studies, an increased risk of exposure-related adverse events in patients who are poor metabolizers cannot be ruled out.
Pseudoephedrine alone is incompletely metabolized (less than 1%) in the liver by N-demethylation to an inactive metabolite. The drug and its metabolite are excreted in the urine. About 55% to 96% of an administered dose of pseudoephedrine hydrochloride is excreted unchanged in the urine.
Elimination:
Following single dose administration of CLARINEX-D 12 HOUR Extended Release Tablets, the mean plasma elimination half-life of desloratadine was approximately 27 hours. In another study, following administration of single oral doses of desloratadine 5 mg, Cmax and AUC values increased in a dose proportional manner following single oral doses between 5 and 20 mg. The degree of accumulation after 14 days of dosing was consistent with the half-life and dosing frequency. A human mass balance study documented a recovery of approximately 87% of the 14C- desloratadine dose, which was equally distributed in urine and feces as metabolic products. Analysis of plasma 3-hydroxydesloratadine showed similar Tmax and half-life values compared to desloratadine.
The mean elimination half-life of pseudoephedrine is dependent on urinary pH. The elimination half-life is approximately 3 to 6 or 9 to 16 hours when the urinary pH is 5 or 8, respectively.
Geriatric Subjects: Following multiple-dose administration of CLARINEX Tablets, the mean Cmax and AUC values for desloratadine were 20% greater than in younger subjects (< 65 years old). The oral total body clearance (CL/F) when normalized for body weight was similar between the 2 age groups. The mean plasma elimination half-life of desloratadine was 33.7 hr in subjects ≥65 years old. The pharmacokinetics for 3-hydroxydesloratadine appeared unchanged in older vs. younger subjects. These age-related differences are unlikely to be clinically relevant and no dosage adjustment is recommended in elderly patients.
Pediatric Subjects: CLARINEX-D 12 HOUR Extended Release Tablets are not an appropriate dosage form for use in pediatric patients below 12 years of age.
Renally Impaired: Following a single dose of desloratadine 7.5 mg pharmacokinetics were characterized in subjects with mild (n=7; creatinine clearance 51–69 mL/min/1.73m2), moderate (n=6; creatinine clearance 34–43 mL/min/1.73m2) and severe (n=6; creatinine clearance 5–29 mL/min/1.73m2) renal impairment or hemodialysis dependent (n=6) subjects. In subjects with mild and moderate renal impairment, median Cmax and AUC values increased by approximately 1.2- and 1.9-fold, respectively, relative to subjects with normal renal function. In subjects with severe renal impairment or who were he |
