Abstract
Abstract: :
Purpose:To determine if pilocarpine at various concentrations is additive to bimatoprost in reducing IOP and to assess the tolerability of this combination. Methods:This is a randomized, prospective clinical trial of patients with IOP between 21 mmHg and 29mmHg following appropriate medication washout. For all visits IOP was measured at 9am and 11am. Following baseline visit (# 1) bimatoprost 0.03% was instilled qhs OU through visit 6. Visit 2 was conducted 3 weeks after visit 1, and visits 2 through 6 were conducted at 4+1 day intervals to assess the IOP–lowering effects of each treatment regimen. Following visits 2, 3 and 4 pilocarpine (2%, 4%, 6%) was instilled qid in one randomly selected eye. The initial dose of 2% pilocarpine was instilled after 11am IOP measurement on visit 2 and final dose administered after 9 am measurement on visit 3. Dosing with 4% pilocarpine was begun after the 11am IOP measurement on visit 3, and with 6% pilocarpine was begun after the 11am IOP measurement on visit 4. Pilocarpine was discontinued after visit 5, and bimatoprost after visit 6. Two–tailed, paired t–test was used at each time point on all visits to compare IOPs of test and control eyes and percentage reduction of IOP from baseline , and to compare IOPs on visits 3 to 5 at 9am and 11am (before and after pilocarpine administration) . The IOP values of different treatment regimens using bimatoprost alone or in combination with various pilocarpine concentrations were compared using Analysis of Variance (ANOVA). Results:11 patients were enrolled in the study. 2 patients were discontinued due to bimatoprost allergies and were excluded from the analysis. Bimatoprost alone caused a mean reduction in IOP of 27.8 + 8.2% (p<0.0001) from baseline to visit 2. Single variant ANOVA showed no significant difference (p>0.9) in IOP for eyes treated with bimatoprost alone or with bimatoprost and various pilocarpine concentrations. There was no significant difference in IOP (p>0.27) or in percentage IOP reduction (p>0.10) from baseline between test and control eyes at 9am and 11am with all three strengths of pilocarpine. IOP values at 9am and 11am, before and after pilocarpine administration respectively, were similar (p>0.27) in test and control eyes during visits 3 to 5. Conclusion:Bimatoprost alone is effective in causing a substantial IOP reduction. Pilocarpine and bimatoprost were well tolerated in combination. Pilocarpine at concentrations of 2%, 4% or 6% demonstrated no additive effects, nor antagonistic effects to the ocular hypotensive efficacy of bimatoprost.
Keywords: intraocular pressure • drug toxicity/drug effects • pharmacology