Abstract
Abstract: :
Purpose: To evaluate the plasma concentrations of LUMIGAN after long-term systemic exposure of patients with glaucoma or ocular hypertension. Methods: Therapeutic drug monitoring was performed in two multi-center, double-masked, randomized, parallel-group, phase 3 studies in 223 patients with glaucoma or ocular hypertension (Studies 008 and 009). Patients were randomized to receive 1 drop of LUMIGAN 0.03% (bimatoprost) ophthalmic solution bilaterally once-daily (QD) in the evening, twice-daily (BID), or timolol 0.5% ophthalmic solution BID for 12 months. Blood samples were collected at 5 minutes after the 8 PM dosing on Day 0 (first dose), months 3, 6, and 12 for the measurement of blood concentrations of bimatoprost and its potential C-1 acid metabolite. Bioanalysis of these two analytes in the blood were determined by a validated liquid chromatography-tandem mass spectrometry (LC-/MS/MS) method with lower limits of quantitation at 0.025 and 0.05 ng/mL, respectively. Results: The potential C-1 acid metabolite concentrations in blood were not quantifiable in either bimatoprost treatment groups. Blood bimatoprost concentrations (ng/mL) from the bimatoprost QD groups are summarized in the following table: Conclusion: Bimatoprost concentrations were low and remained steady over a 12-month period with average blood concentrations less than 0.1 ng/mL in both studies indicating no accumulation during chronic dosing. The results indicate that bimatoprost does not have any appreciable metabolism in humans and is not a prodrug.
Keywords: 514 pharmacology • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • 390 drug toxicity/drug effects