To describe the dose–concentration relationships of carba
mazepine (CBZ) in elderly nursing ho
me residents and the effect of sex, age, and type of co-
medications.
Results
This is a cross-sectional study of elderly (≥65 years) nursing home residents across the United States (N = 92). Data collection was from 1 June 1998 to 31 December 2000. The mean CBZ dose was 9.2 ± 5.4 mg/(kg day−1) (±Standard Deviation) and serum concentration was 5.9 ± 2.2 mg/L. The daily dose was significantly lower in the oldest-old age group (≥85 years, mean 476.9 mg/day (95 % confidence interval CI) 326.5–627.3) as compared to the dose in the young-old (65–74 years, mean 724.4 mg/day (CI) 603.4–845.4) (p = 0.016). Adjusted for body weight, doses were similar on a mg/(kg day−1) basis. The majority of observed CBZ serum concentrations were at the lower end (67.4 % ) or below (20.7 % ) the suggested therapeutic range for younger adult outpatients.
Conclusions
Total daily CBZ doses and patient weight decreased with age. The average dose for elderly nursing home residents was approximately 9 mg/(kg day−1). Carbamazepine serum concentrations were lower than those used for younger adults, suggesting that these patients may be more sensitive to CBZ.
