Purpose: To describe the dose-concentration relationships of carbamazepine (CBZ) in elderly nursing home 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.
Bibliographical noteFunding Information:
This work was supported by a grant from NIH NINDS P50-NS16308. The authors thank PharMerica Pharmacists and Beverly Enterprises, Inc., for their contributions to the study. Some results from this study were presented at the American Epilepsy Society meeting, Los Angeles, CA, December 2000.
- Nursing home