Serum Concentrations and Daily Doses of Carbamazepine Among Elderly Nursing Home Residents
Abstract number :
2.033
Submission category :
Year :
2000
Submission ID :
751
Source :
www.aesnet.org
Presentation date :
12/2/2000 12:00:00 AM
Published date :
Dec 1, 2000, 06:00 AM
Authors :
Angela K Birnbaum, Nancy A Hardie, Jeannine M Conway, Nina M Graves, Sandra E Krause, Thomas E Lackner, Ilo E Leppik, Coll of Pharmacy, Univ of Minnesota, Minneapolis, MN; MINCEP Epilepsy Care, Minneapolis, MN.
RATIONALE: Currently, the elderly receive carbamazepine (CBZ) doses based on studies of younger adults. The purpose of this study was to describe doses and serum concentrations of CBZ among elderly nursing home residents from across the United States. METHODS: Twenty-nine PharMerica consulting pharmacists certified in abstracting data collected CBZ dose and concentration information on 85 elderly (? 65 years of age; mean age: 76.0 ? 7.8) residents in 51 nursing homes in 17 states across the United States. Subjects were from a nationwide nursing home organization, who had been on their current dosage of CBZ for at least 4 weeks and had at least one CBZ concentration between June 1998 and November 1999. Data collected were taken from the first CBZ concentration and daily dose available for each resident. Mean daily dose and serum concentration of those not on inhibiting or inducing co-medications were each compared by gender and age group (65-74, 75-84, 85+ years). Inducing co-medications included phenytoin, primidone and phenobarbital, and inhibiting co-medications included fluvoxamine, fluoxetine, paroxetine, valproic acid and sertraline. RESULTS: Mean daily dose (mg/kg/day) was 8.8 4.7 (median=600 mg/day; n=47) and serum concentration (mg/l) was 6.3 2.2 for residents who were not on an inducer or inhibitor. For this group, mean daily dose was 8.0 2.8 for males (n=11) and 9.0 5.1 for females (n=36) (p > 0.05). Mean serum concentration was 6.8 2.0 for males and 6.2 2.2 for females. The mean CBZ daily doses and concentrations among the three age groups were 7.8 3.0 (n=15), 9.8 5.8 (n=24), and 7.4 2.4 (n=8), and 6.0 2.3, 6.8 2.2, and 5.7 1.8, respectively. The mean CBZ daily dose and concentrations for residents who were taking CBZ and an inhibitor (n=17) was 7.7 3.6 and 5.8 2.3 or CBZ and an inducer (n=18) was 13.4 7.7 and 5.3 2.1, respectively. CONCLUSIONS: CBZ daily doses and serum concentrations were similar among elderly residents who were not on inhibiting or inducing co-medications when compared by age groups. On average, females received higher doses of CBZ which resulted in lower CBZ concentrations than males. [Supported by NIH-NINDS P50-NS16308]