GABAPENTIN ABSORPTION - EFFECT OF MIXING WITH FOODS OF VARYING MACRONUTRIENT COMPOSITION

OBJECTIVE: TO compare the oral absorption profile of gabapentin follow ing administration of the contents of opened capsules that were mixed with food vehicles of varied macronutrient (protein) composition. DESI GN: An unblinded, randomized, single-dose, four-way crossover pharmaco kinetic study in nine healthy adult men and women volunteers, METHODS: Following an overnight fast, a single 600-mg dose of gabapentin (2 x 300-mg Neurontin capsules) was given either as an intact capsule swall owed with 120 mt of tap water (control, phase I), or after capsule con tents were opened and mixed with; 4 oz. of applesauce (phase II), 120 mt of orange juice (phase III), or 4 oz, of fat-free chocolate pudding (phase IV), Subjects fasted for 4 hours following drug ingestion, Ser ial venous blood samples were obtained over 24 hours to determine gaba pentin serum concentrations. Pharmacokinetic variables including AUG, maximum serum concentration (C-max), and time to maximum serum concent ration (t(max)) were calculated by using standard noncompartmental met hods, Subjects served as their own controls, and were randomly crossed over following a minimum 7-day washout period Statistical analysis wa s performed by using ANOVA and Student's t-test where appropriate. RES ULTS: NO statistically significant differences in any kinetic variable were found between any study arm. A trend was noted for a In a compar ison of protein (phase IV) versus nonprotein phases (phases I-III), ga bapentin AUC was 26% greater (47.28 +/- 14.65 vs. 37.43 +/- 9.78 mu g/ mL.h; p = 0.03), and C-max was 32% higher (4.72 +/- 1.04 vs. 356 +/- 0 .92 mu g/mL; p = 0.003). CONCLUSIONS: Opening and mixing the contents of gabapentin capsules does not significantly impair drug absorption. This may be a viable administration option for patients who are unable to swallow intact capsules. Dietary macronutrient composition (i.e., protein) may favorably influence gabapentin oral absorption.