24-hour intraocular pressures with brimonidine purite versus dorzolamide added to latanoprost in primary open-angle glaucoma subjects.
ABSTRACT To evaluate the 24-hour efficacy of brimonidine purite versus dorzolamide, each added to latanoprost.
Double-masked, 2-center, prospective, crossover comparison.
Primary open-angle glaucoma (POAG) subjects.
Subjects were randomized to brimonidine purite or dorzolamide, each given twice daily, for the first 6-week treatment period after a 6-week latanoprost run-in. Subjects began the opposite treatment for the second 6-week period after a 6-week latanoprost-only treatment between periods. Intraocular pressure (IOP) was measured at 8 am, 12 pm, 4 pm, 8 pm, 12 am, 4 am, and 8 am at each baseline and at the end of each treatment period. This study provided an 80% power that a 1.5-mmHg difference could be excluded between groups if 27 subjects completed the study. A standard deviation (SD) of 2.8 mmHg was assumed.
Twenty-four-hour efficacy of intraocular pressures of brimonidine purite versus dorzolamide, each added to latanoprost.
In 31 completed subjects, the baseline mean diurnal 24-hour IOP (+/- SD) was 19.0+/-1.7 mmHg for brimonidine purite and 19.0+/-1.6 mmHg for dorzolamide (P = 0.52). The 8 am IOP after 6 weeks of therapy was 18.4+/-2.1 mmHg for brimonidine purite and 18.9+/-1.9 mmHg for dorzolamide (P = 0.40). The mean diurnal IOP was 16.9+/-1.5 mmHg for brimonidine purite and 16.8+/-1.5 mmHg for dorzolamide (P = 0.66). Dorzolamide caused a more bitter taste (P = 0.01) than brimonidine purite.
This study suggests that brimonidine purite and dorzolamide, added to latanoprost, have similar efficacy and safety in POAG or ocular hypertensive subjects.
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ABSTRACT: The objective was to assess the long-term economic consequences of the medical management of glaucoma in the UK. The economic evaluation was conducted using the results from a 10-year Markov model based around 3 key triggers for a switch in medical therapy for glaucoma, namely: lack of tolerance (using hyperemia as a proxy); intraocular pressure (IOP) not meeting treatment benchmark; and glaucoma progression. Clinical data from a comprehensive systematic literature review and meta-analysis were used. Direct costs associated with glaucoma treatment are considered (at 2008/9 prices) from the perspective of the UK NHS as payer (outpatient/secondary care setting). Using this model, the economic consequences of 3 prostaglandin-based treatment sequences were compared. Drug acquisition costs account for around 8% to 13% of the total cost of glaucoma and, if ophthalmologist visits are included, amount to approximately £0.80 to £0.90 per day of medical therapy. The total long-term costs of all prostaglandin strategies are similar because of a shift in resources: increased drug costs are offset by fewer clinic visits to instigate treatment switches, and by avoiding surgery or costs associated with managing low vision. Under the latanoprost-based strategy, patients would have longer intervals between the need to switch therapies, which is largely due to a reduction in hyperemia, seen as a proxy for tolerance. This leads to a delay in glaucoma progression of 12 to 13 months. For every 1000 clinic appointments, 719 patients can be managed for 1 year with a latanoprost-based strategy compared with 586 or 568 with a bimatoprost or travoprost-based strategy. Drug acquisition costs are not a key driver of the total cost of glaucoma management and the cost of medical therapy is offset by avoiding the cost of managing low vision. Economic models of glaucoma should include the long-term consequences of treatment as these will affect cost-effectiveness. This analysis supports the hypothesis that the economic and clinical benefits can be optimized by minimizing therapy switches.Journal of glaucoma 06/2011; 21(7):433-49. · 1.74 Impact Factor
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ABSTRACT: To evaluate the efficacy of α2-adrenergic agonist (AA) brimonidine and topical carbonic anhydrase inhibitors (CAIs) dorzolamide and brinzolamide in reducing intraocular pressure (IOP) when used as adjunctive therapy to β-blockers (BBs) or prostaglandin analogs (PGAs). Pertinent publications were identified through systematic searches of PubMed, EMBASE, and the Cochrane Controlled Trials Register. Randomized controlled trials comparing AA with CAIs in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT) who had inadequate IOP control with monotherapy of a BB or PGA. The weighted mean differences (WMD) of IOP-lowering efficacy were calculated by performing meta-analysis. The main efficacy measures were the reduction from baseline to end of treatment in IOP at peak, trough, and diurnal curve. Eleven published randomized clinical trials involving 1493 patients were included in the meta-analysis. As adjunctive therapy, the IOP reduction was greater in the brimonidine group than in the CAI group at peak (WMD: 0.99 mmHg [95% confidence interval, 0.45 to 1.53]) and diurnal curve (WMD: 0.62 mmHg [0.07 to 1.18]). As adjunctive therapy to BBs, brimonidine was more effective than CAIs in reducing IOP at peak (WMD: 0.85 mmHg [0.42 to 1.29]) and trough (WMD: 0.47 mmHg [0.12 to 0.83]). As adjunctive therapy to PGAs, brimonidine resulted greater reduction in peak IOP than CAIs (WMD: 1.04 mmHg [0.08 to 2.00]). Conclusions: Brimonidine provides greater IOP-lowering efficacy than topical carbonic anhydrase inhibitors as adjunctive therapy to BBs or PGAs.Current Medical Research and Opinion 02/2012; 28(4):543-50. · 2.37 Impact Factor
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ABSTRACT: Intraocular pressure (IOP) reduction is currently the only therapeutic approach demonstrated to preserve visual function in patients with glaucoma. The first line of glaucoma treatment consists of topical IOP-lowering medications, usually initiated as monotherapy. A significant proportion of patients require more than one medication to reach a target IOP at which optic nerve damage will not progress. As prostaglandin analogues (PGAs) are the most effective class for reducing IOP, one of the other commonly used classes (β-adrenoceptor antagonist [β-blocker], carbonic anhydrase inhibitor or α(2)-adrenoceptor agonist) is frequently combined with a PGA. In the last decade, the use of fixed combinations containing two medications in a single bottle has steadily increased. Fixed combinations have the potential to simplify the dosing regimen, increase patient adherence, avoid the washout effect of the second drop on the first medication instilled, decrease exposure to preservatives and, sometimes, reduce the cost of treatment. Clinical trials have evaluated PGA-based fixed combinations versus unfixed combinations (individual components administered concomitantly) or versus individual monotherapies; however, any advantage that the fixed combinations may have in terms of IOP-lowering efficacy is still debated. For these reasons, the PGA-based fixed combinations are not approved by regulatory authorities in some countries, such as the US. We review the published studies evaluating the efficacy and tolerability of the IOP-lowering unfixed and fixed combination therapies with PGAs. Regarding unfixed combinations, the review shows that α(2)-adrenergic agonists-PGA and carbonic anhydrase inhibitor-PGA combinations seem to be at least as effective at reducing IOP as the β-blocker-PGA combinations. As for the fixed combinations, the review shows that the three PGA-timolol fixed combinations are more effective than their component medications used separately as monotherapy and are better tolerated than the three respective prostaglandins. The three PGA-timolol fixed combinations are less effective at reducing IOP than the unfixed combinations but are better tolerated. The advantage of the fixed combinations in terms of patient adherence and persistence is supported by a very small number of studies and remains to be more accurately determined. Most studies, but not all, seem to show that PGA-timolol fixed combinations are more effective than other available β-blocker fixed combinations (dorzolamide-timolol fixed combinations) at reducing IOP and are similarly tolerated.Drugs 06/2012; 72(10):1355-71. · 4.13 Impact Factor