A single dose pharmacokinetic study showed that the elimination half-lives of acrivastine, the propionic acid metabolite of acrivastine, and pseudoephedrine were prolonged in patients with chronic renal insufficiency. Compared to normal volunteers, the elimination half-life of acrivastine was about 50% increased in patients with mild renal insufficiency (creatinine clearance = 26 to 48 mL/min) and was increased by about 130% in patients with moderate (creatinine clearance = 12 to 17 mL/min) or severe (creatinine clearance 6 to 10 mL/min) renal insufficiency. Oral clearance of acrivastine was diminished by the same magnitude as the half-life was prolonged in each of the three renally impaired groups. The elimination half-life of the propionic acid metabolite of acrivastine was about 140% increased in patients with mild renal insufficiency and about 5 times increased in patients with moderate or severe renal insufficiency.

Compared to normal volunteers, the elimination half-life of pseudoephedrine was about 3 times increased in patients with mild renal insufficiency, about 7 times increased in patients with moderate renal insufficiency, and about 10 times increased in patients with severe renal insufficiency. Oral clearance of pseudoephedrine was diminished by about the same magnitude as the half-life was prolonged in each of the three renally impaired groups (see PRECAUTIONS, Use In Patients With Diminished Renal Function).

The total body load removed by dialysis is approximately 20%, 27% and 38% for acrivastine, the propionic acid metabolite of acrivastine, and pseudoephedrine, respectively, and therefore, a supplemental dose after a dialysis session is not required.

Based on a multiple dose cross study comparison, the apparent volume of distribution for acrivastine was 44% lower in elderly (n = 36, 65-75 yr) than in young volunteers (n = 16, 19-33 yr). This difference could be attributed to the decrease in total body water that occurs with aging. Despite this difference, no appreciable differences in plasma acrivastine concentrations were seen in the elderly compared to the young, and no appreciable accumulation of acrivastine occurred in plasma at steady-state. The elimination half-life for pseudoephedrine was 18% longer in elderly (7.9 hours) than in younger subjects (6.7 hours), presumably due to the decline in average renal function that occurs with aging. Despite this difference, clearance of pseudoephedrine was not appreciably different in elderly and younger subjects. Elderly patients can therefore be given the same dosage as younger patients. SEMPREX-D Capsules are not recommended, however, in patients with renal impairment (see PRECAUTIONS, Use In Patients With Diminished Renal Function and Geriatric Use).

The effect of age and sex on the pharmacokinetic parameters of acrivastine and pseudoephedrine was determined in 93 healthy volunteers who participated in various studies. All of the 93 volunteers were Caucasian (81 males and 12 females); 57 were between the ages of 18 and 38 years and 36 were between the ages of 65 and 75 years. There were no age- or sex-related differences in the pharmacokinetic parameters of either acrivastine or pseudoephedrine.

The effect of race on acrivastine and pseudoephedrine pharmacokinetics was examined by screening data obtained from 1035 patients, age 12 to 71 years, who participated in the eight safety and efficacy studies. No race-related differences were observed in the pharmacokinetics of either acrivastine or pseudoephedrine.