Efficacy and safety of timolol maleate/latanoprost fixed combination versus timolol maleate and brimonidine given twice daily

Long-term medical management of primary open-angle glaucoma and ocular hypertension in the UK: optimizing cost-effectiveness and clinic resources by minimizing therapy switches

PURPOSE

The objective was to assess the long-term economic consequences of the medical management of glaucoma in the UK.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

The management of glaucoma and intraocular hypertension: current approaches and recent advances

In the last decade, numerous novel ocular hypotensive agents have been introduced for the control of intraocular pressure (IOP). Clinicians now have more options than ever in the selection of medical therapy for the treatment of glaucoma and ocular hypertension. When selecting an ocular hypotensive medication for their patients, clinicians should consider not only the IOP-lowering efficacy of an agent, but also the ability of the drug to allow patients to achieve target levels of IOP that are low enough to stop the progression of glaucomatous damage. Other considerations should include how well the drug controls diurnal IOP, the likelihood of serious adverse events, the versatility of the medication for use as an adjunctive agent, as well as other potential attributes (ie, neuroprotection).

Fixed combination of topical brimonidine 0.2% and timolol 0.5% for glaucoma and uncontrolled intraocular pressure

Lowering IOP is the most readily modifiable risk factor to delay the development and progression of glaucoma (POAG). The fixed combination of brimonidine tartrate 0.2% and timolol maleate 0.5% (FCBT) combines a highly selective α2-adrenergic agonist (brimonidine) with a non-selective β-blocker (timolol). FCBT reduces aqueous production and enhances uveoscleral outflow. Concomitant brimonidine and timolol have additive effects on reducing intraocular pressure (IOP). Multi-center randomized control trials have documented superiority of FCBT twice daily on IOP control compared with monotherapy with the individual components, and equal efficacy compared with concomitant therapy. IOP reduction with FCBT versus fixed combination dorzolamide 2% and timolol 0.5% (FCDT) was similar in a small study. Other studies (n > 293) evaluating concomitant brimonidine and timolol have shown that it is not inferior to FCDT. However, concomitant brimonidine and timolol administered twice daily was significantly less efficacious in IOP reduction than fixed combination latanoprost 0.005% and timolol 0.5% (FCLT). There are no published studies comparing FCBT with FCLT. The side effect profile for FCBT reflects that of its individual components. FCBT was generally well tolerated, with less ocular side effects than brimondine alone, but more than timolol alone. Documented systemic effects were few, although this could be confounded by selection bias. FCBT is a safe and effective IOP lowering agent for POAG and ocular hypertension.

[Effect on ocular blood flow of Combigan® versus placebo in patients with ocular hypertension]

PURPOSE

This study was undertaken to compare the ocular haemodynamic effects of Combigan(®) versus placebo in patients with ocular hypertension (OHT).

METHODS

Thirty patients with OHT were included in a controlled, randomised, double blind study in two parallel groups; 15 were randomised to receive Combigan(®) and 15 to receive placebo for a period of 3 months. At baseline and at 3 months retrobulbar blood flowmeasurements of the ophthalmic artery (OA) and central retinal artery (CRA) were taken using colour Doppler imaging(CDI) ultrasound, concurrently with intraocular pressure (IOP).

RESULTS

Combigan(®) significantly reduced IOP after 3 months of treatment (P = 0.001), whereas placebo showed no significant change in IOP. The baseline haemodynamic parameters were similar between treatment and placebo groups. Patients treated with Combigan® showed a statistically significant decrease in CRA resistive index (P = 0.007).

CONCLUSIONS

Patients treated for 3 months with Combigan(®) showed a significant decrease of CRA resistive index that could be explained by the decrease in IOP.

Clinical utility and differential effects of prostaglandin analogs in the management of raised intraocular pressure and ocular hypertension

Prostaglandin analogs (PGA) are powerful topical ocular hypotensive agents available for the treatment of elevated intraocular pressure (IOP). Latanoprost 0.005% and travoprost 0.004% are prodrugs and analogs of prostaglandin F2α. Bimatoprost 0.03% is regarded as a prostamide, and debate continues as to whether it is a prodrug. The free acids of all 3 PGAs reduce IOP by enhancing uveoscleral and trabecular outflow via direct effects on ciliary muscle relaxation and remodeling of extracellular matrix. The vast majority of clinical trials demonstrate IOP-lowering superiority of latanoprost, bimatoprost and travoprost compared with timolol 0.5%, brimonidine 0.2%, or dorzolamide 2% monotherapy. Bimatoprost appears to be more efficacious in IOP-lowering compared with latanoprost, with weighted mean difference in IOP reduction documented in one meta-analysis of 2.59% to 5.60% from 1- to 6-months study duration. PGAs reduce IOP further when used as adjunctive therapy. Fixed combinations of latanoprost, bimatoprost or travoprost formulated with timolol 0.5% and administered once daily are superior to monotherapy of its constituent parts. PGA have near absence of systemic side effects, although do have other commonly encountered ocular adverse effects. The adverse effects of PGA, and also those found more frequently with bimatoprost use include ocular hyperemia, eyelash growth, and peri-ocular pigmentary changes. Iris pigmentary change is unique to PGA treatment. Once daily administration and near absence of systemic side effects enhances tolerance and compliance. PGAs are often prescribed as first-line treatment for ocular hypertension and open-angle glaucoma.

Mixed treatment comparison and meta-regression of the efficacy and safety of prostaglandin analogues and comparators for primary open-angle glaucoma and ocular hypertension

OBJECTIVES

Primary open-angle glaucoma (POAG) is a chronic condition characterised by optic neuropathy and vision loss. Elevated intraocular pressure (IOP) can damage the optic nerve and is a risk factor for glaucoma, thus treatment usually comprises topical hypotensives. This analysis aims to address methodological issues associated with the synthesis of glaucoma clinical trial data, given variations in study methodology and IOP measurement.

METHODS

Meta-regression was used to estimate how IOP varies over time for patients receiving treatment. Relative treatment effects were assessed using a random-effects mixed treatment comparison (MTC) in order to preserve randomisation and avoid selection bias. To produce clinically meaningful outputs, these analyses were combined to obtain the mean on-treatment IOP and the proportion of patients achieving different IOP targets at different time points. A further MTC estimated the probability of hyperaemia events.

RESULTS

The analysis showed that after 3 months' treatment, between 58 and 83% of patients will have a > or =20% reduction in IOP and 70-93% of patients will have an absolute IOP <20 mmHg. Latanoprost and bimatoprost were found to produce significantly lower on-treatment IOP compared with timolol (p < 0.05); the difference between latanoprost and bimatoprost was not significant. Travoprost produced a lower mean IOP compared with timolol (not significant). Latanoprost-timolol was found to produce significantly lower IOP than latanoprost alone or beta-blockers. The probability of hyperaemia-type events varied between treatments from 14.8 to 63.03%. Latanoprost had significantly lower odds of hyperaemia than travoprost, bimatoprost, travoprost-timolol, or bimatoprost-timolol.

CONCLUSION

This analysis suggests that latanoprost and bimatoprost produce a statistically significant reduction in IOP compared with timolol, but are associated with a higher risk of hyperaemia. Out of all the prostaglandins, latanoprost may achieve a good balance between tolerability and IOP efficacy. As with all forms of meta-analysis, the results are based on the assumption that the studies and intervention groupings are sufficiently similar to be compared.

Administration of the fixed combination of latanoprost 0.005% and timolol 0.5% in glaucoma patients with an intraocular pressure over 30 mmHg

Purpose:

To evaluate the intraocular pressure (IOP) reducing effect of a fixed combination of 0.005% latanoprost and 0.5% timolol in patients with an IOP of 30 mmHg or higher.

Design:

Prospective, randomized clinical trial.

Participants:

Twenty-eight patients.

Methods:

Patients had received no prior medical glaucoma treatment. Routine ophthalmic examinations and visual field tests were performed before and after treatment for each patient.

Results:

Mean IOP was 32.28 ± 0.92 mmHg before treatment. Mean IOP levels were 18.75 ± 0.68 for the first day, 17.96 ± 0.90 for the first week and 17.64 ± 0.66 for the first month after treatment.

Conclusion:

A fixed combination of latanoprost 0.005% and timolol 0.5% is effective in significantly reducing IOP in glaucoma patients with an IOP greater than 30 mmHg.

Reporting of noninferiority and equivalence randomized trials for major prostaglandins: a systematic survey of the ophthalmology literature

BACKGROUND

Standards for reporting clinical trials have improved the transparency of patient-important research. The Consolidated Standards of Reporting Trials (CONSORT) published an extension to address noninferiority and equivalence trials. We aimed to determine the reporting quality of prostaglandin noninferiority and equivalence trials in the treatment of glaucoma.

METHODS

We searched, independently and in duplicate, 6 electronic databases for eligible trials evaluating prostaglandins. We abstracted data on reporting of methodological criteria, including reporting of per-protocol [PP] and intention-to-treat [ITT] analysis, sample size estimation with margins, type of statistical analysis conducted, efficacy summaries, and use of hyperemia measures.

RESULTS

Trials involving the four major prostaglandin groups (latanoprost, travoprost, bimatoprost, unoprostone) were analyzed. We included 36 noninferiority and 11 equivalence trials. Seventeen out of the included 47 trials (36%, 95% Confidence Intervals [CI]: 24-51) were crossover designs. Only 3 studies (6%, 95% CI: 2-17) reported a presented results of both ITT and PP populations. Twelve studies (26%, 95% CI: 15-39) presented only ITT results but mentioned that PP population had similar results. Thirteen trials (28%, 95% CI: 17-42) presented only PP results with no mention of ITT population results while 17 studies (36%, 95% CI: 24-51) presented only ITT results with no mention of PP population results. Thirty-four (72%, 95% CI: 58-83) of studies adequately described their margin of noninferiority/equivalence. Sequence generation was reported in 22/47 trials (47%, 95% CI: 33-61). Allocation concealment was reported in only 10/47 (21%, 95% CI: 12-35) of the trials. Thirty-five studies (74%, 95% CI: 60-85) employed masking of at least two groups, 4/47 (9%, 95% CI: 3-20) masked only patients and 8/47 (17%, 95% CI: 9-30) were open label studies. Eight (17%, 95% CI: 9-30) of the 47 trials employed a combined test of noninferiority and superiority. We also found 6 differing methods of evaluating hyperemia.

CONCLUSION

The quality of reporting noninferiority/equivalency trials in the field of glaucoma is markedly heterogeneous. The adoption of the extended CONSORT statement by journals will potentially improve the transparency of this field.

Efficacy and safety of latanoprost versus pilocarpine/timolol maleate fixed combination in patients with primary open-angle glaucoma or ocular hypertension

PURPOSE

This study aimed to compare the safety and effect on intraocular pressure (IOP) of latanoprost given every evening versus pilocarpine/timolol maleate fixed combination (PTFC) given twice daily in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OH).

METHODS

Following a 6-week, medicine-free period, qualified patients were randomized for Period 1 to either placebo administered every morning and latanoprost every evening or to PTFC administered twice daily. After 8 weeks of treatment, IOP was measured at 08.00, 10.00, 16.00 and 18.00 hours. Patients were then switched to the opposite treatment and underwent a second diurnal evaluation at the end of Period 2.

RESULTS

Thirty-two patients completed this study. They demonstrated diurnal baseline IOP of 24.1 +/- 2.4 mmHg. Mean diurnal pressure was 16.8 +/- 2.1 mmHg on PTFC and 16.9 +/- 2.5 mmHg on latanoprost (p = 0.60). No statistical difference between treatments was observed at any individual time-point except at 10.00 hours, when the PTFC group demonstrated an IOP of 15.9 +/- 2.3 mmHg and latanoprost 16.8 +/- 2.7 mmHg (p = 0.02). There were no statistical differences between groups in unsolicited systemic or ocular adverse events (p > 0.05). However, the PTFC group showed a narrower pupil diameter (2.3 mm) than the latanoprost group (3.7 mm). Additionally, a solicited symptom survey demonstrated mild blurred vision, stinging and ocular pain with PTFC (p < 0.001).

CONCLUSIONS

Both PTFC and latanoprost are efficacious in reducing diurnal IOP in POAG or OH. However, PTFC may be more effective in the late morning and may have a greater incidence of mild ocular side-effects.

Dorzolamide/timolol fixed combination versus latanoprost/timolol fixed combination in patients with primary open-angle glaucoma or ocular hypertension

PURPOSE

The efficacy of dorzolamide/timolol fixed combination (DTFC) versus latanoprost/timolol fixed combination (LTFC) in open-angle glaucoma or ocular hypertensive patients.

METHODS

Patients were randomized to DTFC or LTFC for 6 weeks and switched to opposite treatment for Period 2.

RESULTS

Thirty-two completed patients had a mean diurnal IOP of 19.5+/-3.2 mmHg for DTFC and 18.9+/-3.4 mmHg for LTFC (p=0.12), with no significant difference found between DTFC and LTFC at any timepoint following a Bonferroni correction (p>or=0.01).

CONCLUSIONS

Patients treated with DTFC and LTFC have a statistically similar ocular hypotensive effect.

Comparison of intraocular pressure lowering effect of once daily morning vs evening dosing of latanoprost/timolol maleate combination

PURPOSE

To compare intraocular pressure (IOP) reduction profiles of latanoprost-timolol maleate fixed combination (LTFC) administered in the morning or evening in primary open angle glaucoma (POAG).

METHODS

A prospective, randomized study including 60 eyes of 30 patients with POAG was carried out. Patients were randomized to treatment with LTFC at 8 PM (Group 1) or at 8 AM (Group 2). After therapy of 4 weeks, IOP was measured at 2 AM, 6 AM,10 AM, 2 PM, 6 PM, and 10 PM and compared with baseline values and latanoprost therapy alone.

RESULTS

Mean diurnal baseline IOPs and IOPs after treatment with latanoprost and LTFC were 23.6+/-2.6, 16.7+/-2.3, and 15.5+/-2.2 mmHg in Group 1 and 23.1+/-2.6, 16.9+/-2.4, and 15.7+/-2.4 mmHg in Group 2. LTFC lowered IOP more than latanoprost at all time points in both groups (p<0.001) (except 6 AM in Group 2). The mean IOP range after LTFC therapy was lower than the baseline in Group 1 whereas it was not different in Group 2. IOP at 10 AM was significantly higher than the other time points at baseline measurements in both groups (p<0.01) but after treatment there was no difference (p>0.05). According to IOP reduction from baseline, there was a statistically significant difference between groups in favor of Group 1 at 6 AM, 10 AM, and mean diurnal measurement (p<0.01).

CONCLUSIONS

Both morning and evening dosing of LTFC were effective in lowering diurnal IOP in patients with POAG. However, evening dosing of LTFC seemed to be more effective in controlling IOP especially in the morning and avoiding the fluctuations with lower range of IOP.

Meta-analysis of 24-hour intraocular pressure studies evaluating the efficacy of glaucoma medicines

PURPOSE

To evaluate efficacy and safety data of currently available ocular hypotensive medicines derived from 24-hour studies, of similar design, in patients with primary open-angle glaucoma (POAG), exfoliative glaucoma, or ocular hypertension (OH).

DESIGN

Meta-analysis of published articles evaluating patients with POAG, exfoliative glaucoma, or OH.

METHODS

We included articles that were randomized, prospective, single- or double-masked, comparative studies of ocular hypotensive therapies over 24 hours. Each article selected contained an untreated baseline, >or=4-week treatment period, >/=20 patients per treatment arm, and >or=6 time points not spaced >5 hours apart and used Goldmann applanation or Tonopen tonometry (supine measurements) to measure intraocular pressure (IOP).

MAIN OUTCOME MEASURE

Twenty-four-hour IOP efficacy.

RESULTS

This analysis included 864 separate 24-hour treatment curves from 386 patients in 28 treatment arms from 11 studies. A statistical difference in the mean diurnal pressure decrease existed between monotherapy treatments for POAG/OH patients, with bimatoprost (29%) and travoprost (27%) showing the greatest 24-hour reduction (P = 0.026). Timolol 0.5% was less effective than latanoprost (24% vs. 19% reduction) but decreased the pressure at each night time point (P = 0.0003). Dorzolamide showed a 19% 24-hour pressure reduction and brimonidine 0.2% a 14% one. In exfoliative glaucoma patients, latanoprost and travoprost showed higher baseline and treatment pressures, although the pressure reductions (29% and 31%, respectively) were greater generally than observed with POAG/OH. An evening-dosed latanoprost/timolol fixed combination reduced the pressure 33%, and the dorzolamide/timolol fixed combination (DTFC), 26%. However, the power to detect a difference for this specific comparison was probably low, due to the limited number of patients (n = 20) in the DTFC group. A statistical difference between evening-dosed (24%) and morning-dosed (18%) latanoprost (P<0.0001) was noted, but not between evening (27%) and morning (26%) travoprost (P = 0.074). The mean reduction of night time points was statistically lower than day time points for latanoprost (P = 0.031), timolol (P = 0.032), and brimonidine (P = 0.050), but not for dorzolamide. Dorzolamide (P = 0.60), travoprost (P = 0.064), and bimatoprost (P = 0.057) did not demonstrate nighttime pressures lower than daytime ones. The mean reduction of night time points was statistically lower than that of day time points for latanoprost (P = 0.031), timolol (P = 0.032), and brimonidine (P = 0.050), but not for dorzolamide (P = 0.60), bimatoprost (P = 0.057), travoprost (P = 0.064).

CONCLUSIONS

Similar relative efficacies generally exist in various classes of ocular hypotensive agents during night and day hours.

Effects of topical antiglaucoma medications on the ocular surface

The side effects of topical antiglaucoma medications and their preservatives range from ocular discomfort to sight-threatening alterations of the ocular surface. Conjunctival hyperemia, decreased tear production and function, and superficial punctate keratitis are among the most common signs seen on routine clinical examination. Squamous cell metaplasia and changes in cell morphology have been demonstrated by impression cytology studies and evaluation of biopsy specimens, and inflammatory effects are documented by the presence of inflammatory markers. The adverse effects of topical antiglaucoma eyedrops interfere with the treatment of glaucoma on two levels: first, the discomfort produced by the eye drops discourages patient compliance; and, second, long-term treatment with eyedrops is associated with a higher failure of filtration surgery. The detailed mechanism of inflammatory response and/or direct toxicity of eye drops has yet to be determined, but it may vary with the different classes of eye drops, different preservatives, and durations of treatments. Upcoming multicenter trials for new antiglaucoma eye drops should specifically evaluate ocular surface effects.

Predictive value of the efficacy of glaucoma medications in regulatory trials: Phase I-III to post-marketing studies

PURPOSE

To determine the predictive value of early Phase trials (I-II) for the ocular hypotensive efficacy observed in Phases III and IV.

DESIGN

A review of published literature.

METHODS

This study evaluated 12 medicines in 65 articles in the literature with at least two phases available.

RESULTS

For medicines with Phase I results available (n=3), the average reduction in intraocular pressure (IOP) from untreated baseline was 16%, 26% for Phase II, 26% for Phase III, and 24% for Phase IV. For medicines with Phase II results available (n=6), the average reduction in IOP was 23%, 24% for Phase III, and 23% for Phase IV. For medicines with Phase III results available (n=11), the average reduction in IOP was 25% and 24% for Phase IV.

CONCLUSION

This study indicates that early phase trials usually approximated the results of later regulatory studies and post-commercialization trials.

Tolerability, quality of life, and persistency of use in patients with glaucoma who are switched to the fixed combination of latanoprost and timolol

This study was undertaken to assess tolerability, quality of life, and persistency of use and to monitor changes in intraocular pressure (IOP) during the first 6 mo after a switch to fixed combination latanoprost/timolol. In Germany, 271 general ophthalmology practices enrolled patients who were switched from previous ocular hypotensive therapies to latanoprost/timolol for medical reasons. Usual care routines were followed, and IOP was measured at baseline and approximately 6 mo later. Adverse events were recorded throughout. Immediately before switching and at follow-up, patients completed a 29-item quality-of-life questionnaire. Of 1052 patients who met analysis criteria, 748 (71%) switched from combination therapy and 304 (29%) from monotherapy. An insufficient IOP reduction with the previous therapy was a reason for switching in 71% of patients; the desire to simplify to once-daily administration was cited in 66%. Ocular adverse events were reported in 19 patients after the switch, and 97% remained on therapy throughout the follow%up period. After switching, patients were less likely to forget to instill their eyedrops or to feel that their drops had adverse effects; they found it easier to include eyedrop administration in their routine; they were more satisfied with the frequency of instillation; and they were more likely to want to continue with the drops. Across all previous therapies, mean IOP decreased from 20.6+/-3.7 mm Hg to 17.2+/-2.8 mm Hg after the switch (P<.001)-a 14.8% difference. Fixed combination latanoprost/timolol is well tolerated and effective in patients who are switched from other monotherapies or combination therapies for medical reasons. Such a switch may be associated with improved quality of life.

Meta-analysis of randomised controlled trials comparing latanoprost with brimonidine in the treatment of open-angle glaucoma, ocular hypertension or normal-tension glaucoma

AIM

To compare the efficacy and tolerability of latanoprost versus brimonidine in the treatment of open-angle glaucoma, ocular hypertension or normal-tension glaucoma.

METHOD

Systematic review of randomised controlled trials comparing latanoprost and brimondine, identified by searches including Medline, Embase and Cochrane Controlled Trials Register. Two reviewers independently assessed trials for eligibility and quality and extracted data. Data were synthesised (random effects model) and expressed as the absolute mean intraocular pressure (IOP) reduction difference from baseline to end point for efficacy and relative risk for adverse events. Subgroup analysis and regression were used to explore heterogeneity according to patient characteristics, trial design and quality.

RESULTS

15 publications reporting on 14 trials (1784 participants) were included for meta-analysis. IOP reduction favoured latanoprost (weighted mean difference (WMD) = 1.10 mm Hg (95% confidence interval (CI) 0.57 to 1.63)). Significant heterogeneity was present (chi(2)(13) = 38.29, p = 0.001, I(2) = 66.0%). Subgroup analysis showed greater WMD for studies where data were analysed from end points >6 months duration, cross-over design, open-angle glaucoma or ocular hypertension and monotherapy. Multiple regression showed no significant association of WMD with trial duration (t(9) = 1.92, p = 0.09), trial design (t(9) = 1.79, p = 0.11), trial quality (t(9) = -0.46, p = 0.66), or monotherapy or adjunctive therapy (t(9) = -2.14, p = 0.06). Fatigue was less commonly associated with latanoprost (RR = 0.27, 95% CI 0.08 to 0.88). Publication bias was not evident on visual inspection of a funnel plot.

CONCLUSION

Latanoprost is more effective than brimonidine as monotherapy in lowering IOP. Brimonidine is associated with a higher rate of fatigue.

A 12-week, randomized, double-masked, multicenter study of the fixed combination of latanoprost and timolol in the evening versus the individual components

PURPOSE

To compare the efficacy and tolerability of fixed-combination latanoprost and timolol applied in the evening with the concomitant use of the individual components.

DESIGN

Twelve-week, randomized, double-masked, multicenter study.

PARTICIPANTS

Five hundred seventeen randomized patients with ocular hypertension; open-angle, pigmentary, or exfoliation glaucoma; and baseline (after washout) intraocular pressure (IOP) levels between 23 and 33 mmHg.

METHODS

Patients received either the fixed combination of latanoprost and timolol once daily in the evening and a placebo in the morning and evening or the unfixed combination of latanoprost once daily in the evening and timolol in the morning and evening. Study visits were at weeks 2, 6, and 12.

MAIN OUTCOME MEASURES

The primary efficacy end point was mean change from baseline to week 12 in diurnal IOP (mean IOPs of 8 am, 12 pm, and 4 pm). The fixed combination was considered noninferior to the unfixed combination if the upper limit of the 95% confidence interval (CI) of the difference was <1.5 mmHg (analysis of covariance). Adverse events were recorded at each visit.

RESULTS

In all, 502 patients were included in intent-to-treat analyses (fixed combination, n = 255; unfixed combination, n = 247). For the fixed- and unfixed-combination groups, mean baseline diurnal IOP levels were 25.4 mmHg and 25.2 mmHg, respectively, and mean diurnal IOP reductions were 8.7 mmHg and 9.0 mmHg (between-treatment difference, 0.3 mmHg; 95% CI, -0.1 to 0.7 mmHg; P = 0.15). Both treatments were well tolerated.

CONCLUSIONS

The fixed combination of latanoprost and timolol administered once daily in the evening is not inferior to the unfixed combination of latanoprost once daily in the evening and timolol twice daily. The fixed combination provides an effective and well-tolerated alternative to multiple instillations.

Analytic review of bimatoprost, latanoprost and travoprost in primary open angle glaucoma

OBJECTIVE

The objective of this review was to evaluate different measures of efficacy of the intraocular pressure (IOP) lowering lipid class agents bimatoprost, latanoprost and travoprost in the treatment of primary open angle glaucoma. Study arms of timolol in trials including the above mentioned lipid class drugs were also included.

METHODS

MEDLINE and EMBASE were searched for randomized clinical trials including one or more of the lipid class drugs bimatoprost, latanoprost and travoprost. The study results were pooled, and the simple, weighted IOP-lowering efficacy was compared among the lipid class drugs and timolol, where data were available. Efficacy parameters were reviewed, including mean reduction of IOP and percentage of patients achieving different levels of IOP.

RESULTS

161 articles were identified of which 42 were included in the analysis. A total of 9295 patients participated in the included trials. Based on all studies, timolol on average had a weighted mean IOP reduction of 22.2%, while latanoprost, travoprost and bimatoprost had a weighted mean IOP reduction of 26.7%, 28.7% and 30.3%, respectively. Analysis of target achievement to various IOP levels shows that bimatoprost seems more efficacious than latanoprost. The direct comparisons (head-to-head studies) also show that bimatoprost is the most efficacious treatment, however it is not conclusive whether latanoprost or travoprost is better in reducing IOP.

CONCLUSIONS

This review shows that bimatoprost seems to be the most efficacious treatment in lowering IOP. Head-to-head studies confirm this.

An evaluation of the fixed-combination of latanoprost and timolol for use in open-angle glaucoma and ocular hypertension

Glaucoma is one of the leading causes of irreversible blindness worldwide. Although there is no cure for this chronic disease, medical treatment is aimed at reducing levels of intraocular pressure (IOP) using ocular hypotensive agents. Very often, patients require more than one IOP-reducing drug, resulting in complex medication regimens that may be difficult to maintain and that can lead to non-compliance. A fixed-combination (FC) ophthalmic solution consisting of the prostaglandin, latanoprost (0.005%), and the beta-blocker, timolol (0.5%), is now available. The primary mechanism of action of latanoprost is to increase uveoscleral outflow whereas timolol lowers IOP levels by decreasing the formation of aqueous humor in the ciliary epithelium. Due to the unique mechanism of action of latanoprost, once-daily dosing of one drop of FC latanoprost/timolol results in additional IOP reduction compared with either drug administered separately. FC latanoprost/timolol is well-tolerated and has a safety profile similar to that of its individual components. This combination drug provides a safe, effective and convenient alternative for the treatment of patients with elevated IOP levels uncontrolled with monotherapy.

Intraocular pressure and safety in glaucoma patients switching to latanoprost/timolol maleate fixed combination from mono- and adjunctive therapies

PURPOSE

The aim of this study was to evaluate the efficacy and safety in ocular hypertensive or open-angle glaucoma patients changed to a latanoprost/timolol fixed combination (LTFC) from previous therapy.

METHODS

We employed a retrospective, multicenter, active-controlled study evaluating patients who had a previous therapy substituted with LTFC and had a 3-month follow-up.

RESULTS

In the 168 patients included in the trial, LTFC reduced the intraocular pressure (IOP) after switching from previous therapies: timolol (22.8+/-3.5 to 19.0+/-3.9 mmHg, N=49, p<0.001), latanoprost (21.2+/-3.8 to 18.3+/-2.5 mmHg, N=54, p<0.001), and a dorzolamide/timolol fixed combination (20.9+/-2.4 to 20.0+/-2.7 mmHg, N=32, p=0.03). In switching from a latanoprost and timolol unfixed combination, the pressure changed from 18.3+/-3.8 to 18.9+/-3.0 mmHg (N=33, p=0.38). LTFC was persistent in 131 (78%) patients within the 3-month treatment period. The most common adverse event with LTFC was conjunctival hyperemia, which occurred in patients not previously treated with latanoprost therapy (N=16, 10%).

CONCLUSIONS

LTFC generally provides reduced IOP and limited side effects when substituted for other common glaucoma therapies, while providing similar pressure when switched from its own individual components.

Short term efficacy and safety in glaucoma patients changed to the latanoprost 0.005%/timolol maleate 0.5% fixed combination from monotherapies and adjunctive therapies

AIMS

To evaluate efficacy and safety in patients with ocular hypertension or open angle glaucoma changed to latanoprost/timolol fixed combination (LTFC).

METHODS

A prospective, multicentre, historical control in which qualified patients had their previous therapy substituted by LTFC and were followed for at least 2 months.

RESULTS

In 1676 patients LTFC was continued in 93% throughout the observation period. In all patients LTFC reduced the intraocular pressure (IOP) from 20.6 (SD 3.8) to 17.7 (3.0) mm Hg (p<0.001) compared to previous monotherapies including latanoprost, timolol, alpha agonists or carbonic anhydrase inhibitors (CAI). LTFC provided more efficacy after changing from adjunctive therapies including: a beta blocker added to either CAI, alpha agonist, or pilocarpine, or CAI added to an alpha agonist, or latanoprost added to either CAI, alpha agonist, or beta blocker (unfixed combination), and travoprost added to timolol (p<0.007). LTFC was as effective as latanoprost used with dorzolamide/timolol fixed combination (-0.9 mm Hg, p = 0.1792). The most common reason to discontinue therapy was lack of efficacy (n = 70, 4%) and adverse event (n = 17, 1%).

CONCLUSION

In a clinical setting, patients who have their monotherapy or adjunctive therapy substituted with LTFC may experience reduced IOP, good tolerability, and continuation of therapy for the first 2-3 months of treatment.

Concomitant administration of travoprost and brinzolamide versus fixed latanoprost/timolol combined therapy: three-month comparison of efficacy and safety

PURPOSE

To compare the efficacy and safety of the concomitant administration of travoprost 0.004% once daily and brinzolamide 0.1% twice daily with those of a fixed combination of latanoprost 0.005%/timolol 0.5% once daily.

RESEARCH, DESIGN AND METHODS

Forty-four patients with primary open-angle glaucoma or ocular hypertension with elevated IOP insufficiently responsive to monotherapy were randomly assigned to one of the two treatment groups: concomitant administration of travoprost 0.004% once daily and brinzolamide 0.1% twice daily (TB group: 22 patients) or latanoprost 0.005% plus timolol 0.5% once daily (LT group: 22 patients). Visits were undertaken at screening (current ocular hypotensive therapy was discontinued), baseline (randomization), and after 2 weeks, 1 month, 2 months and 3 months of therapy.

MAIN OUTCOME MEASURES

IOP was determined at 9 a.m., 12 p.m. and 4 p.m. at each study visit, and diurnal IOP was calculated as the mean of these recordings. Adverse events were recorded at each visit.

RESULTS

IOP at the baseline visit was similar in both groups. Overall mean IOP was significantly lower in the TB as compared to the LT group after 1 month, 2 month and 3 month follow-up; only 9 a.m. measurements were significantly different, reaching a maximum difference (16.9 +/- 0.9 mmHg vs 18.4 +/- 1.8 mmHg, p < 0.001) at the 3 month check. The percentage of responders (IOP decrease > or = 30%) was higher in the TB group. Both treatments were well tolerated and there were no cases of withdrawal from treatment.

CONCLUSIONS

Travoprost 0.004% and brinzolamide 0.1% concomitant therapy showed a greater efficacy than the fixed latanoprost 0.005%/timolol 0.5% combination in terms of absolute IOP decreases. Travoprost/brinzolamide therapy also offered the advantages of a greater percentage of responders.

Brimonidine purite 0.15% versus dorzolamide 2% each given twice daily to reduce intraocular pressure in subjects with open angle glaucoma or ocular hypertension

BACKGROUND/AIMS

To evaluate the efficacy of brimonidine purite versus dorzolamide given twice daily in primary open angle glaucoma or ocular hypertensive subjects.

METHODS

In this double masked, multicentre, prospective, crossover comparison 33 subjects were randomised to brimonidine purite or dorzolamide for the first 4 week treatment period after a 4 week washout. Subjects began the opposite treatment for the second 4 week period after another 4 week washout. Intraocular pressure (IOP) was measured at 08:00 (trough) and 10:00, 18:00, and 20:00 hours after dosing at each baseline and at the end of each treatment period.

RESULTS

The baseline diurnal IOP was 22.9 (SD 2.8) for brimonidine purite and 22.2 (SD 2.4) mm Hg for dorzolamide. The trough IOP following 4 weeks of therapy was 21.0 (SD 3.7) for brimonidine purite and 21.0 (SD 3.1) mm Hg for dorzolamide (p = 0.90). The mean diurnal IOP was 19.3 (SD 3.1) for brimonidine purite and 19.8 (SD 2.4) mm Hg for dorzolamide (p = 0.46). Dorzolamide caused more ocular stinging upon instillation (n = 8) than brimonidine purite (n = 1) (p = 0.02). No statistical differences existed between groups for systemic adverse events.

CONCLUSIONS

This study suggests that brimonidine purite and dorzolamide each given twice daily have similar efficacy in primary open angle glaucoma or ocular hypertensive subjects. However, a trend was observed at 10:00 of greater brimonidine purite efficacy compared with dorzolamide.

Daytime diurnal curve comparison between the fixed combinations of latanoprost 0.005%/timolol maleate 0.5% and dorzolamide 2%/timolol maleate 0.5%

PURPOSE

The diurnal efficacy and safety of the fixed combinations of latanoprost/timolol given once daily vs dorzolamide/timolol given twice daily in primary open-angle glaucoma or ocular hypertensive patients.

DESIGN

A double-masked, two-centre, crossover comparison.

RESULTS

In 33 patients, the mean diurnal IOP (0800-2000, measured every 2 h) for latanoprost/timolol fixed combination was 17.3+/-2.2 mmHg and for dorzolamide/timolol, the fixed combination was 17.0+/-2.0 mmHg (P = 0.36). Additionally, there was no statistical difference for individual time points following a Bonferroni correction. A bitter taste was found more frequently with the dorzolamide/timolol fixed combination (n = 6) than the latanoprost/timolol fixed combination (n = 0) (P = 0.040), while the latanoprost/timolol fixed combination demonstrated more conjunctival hyperaemia (n = 9) than the dorzolamide/timolol fixed combination (n = 2) (P = 0.045). One patient was discontinued early from the dorzolamide/timolol fixed combination due to elevated IOP.

CONCLUSION

This study suggests that the daytime diurnal IOP is not statistically different between the dorzolamide/timolol fixed combination and latanoprost/timolol fixed combination in primary open-angle glaucoma and ocular hypertensive patients.

Fixed combinations of topical glaucoma medications

PURPOSE OF REVIEW

Topical medical therapy remains the first line of treatment in the management of glaucoma. Utilization studies and clinical trials have demonstrated that many patients with glaucoma require multiple medications to achieve adequate control of intraocular pressure. Fixed combinations of commonly used drugs have been developed, tested, and in some (but not all) cases, approved for use in the United States and abroad. In this review the authors discuss the principles of fixed combination therapy and examine the existing fixed combinations.

RECENT FINDINGS

The first modern combination product was the dorzolamide-timolol fixed combination. It works better than either constituent and at least as well as concomitant therapy with both constituents. In comparison with newer agents, the dorzolamide-timolol fixed combination was equal in efficacy to latanoprost monotherapy, timolol and unoprostone concomitant therapy, and timolol and brimonidine concomitant therapy. Concomitant latanoprost and brimonidine demonstrated better efficacy than the dorzolamide-timolol fixed combination. The latanoprost-timolol fixed combination is available in many countries but not the United States. This combination has demonstrated modest additional efficacy over latanoprost monotherapy. The latanoprost-timolol fixed combination provided greater efficacy than concomitant timolol and brimonidine.

SUMMARY

Fixed combinations offer benefits of convenience, cost, and safety, but limit individualization of dosing. Understanding the advantages and disadvantages of prescribing fixed combinations facilitates success in using these products in clinical practice.

Brimonidine 0.2% vs unoprostone 0.15% both added to timolol maleate 0.5% given twice daily to patients with primary open-angle glaucoma or ocular hypertension

PURPOSE

To compare the efficacy and safety of brimonidine 0.2% vs unoprostone 0.15%, both added to timolol maleate 0.5% each given twice daily.

METHODS

In this prospective, multi-centred, double-masked, crossover comparison, patients were randomized to one treatment group for a 6-week treatment period, and then crossed over to the opposite treatment. Measurements were performed at 0800, 1000, 1600, 1800, and 2000 h at baseline and at the end of each treatment period.

RESULTS

In all, 33 patients entered this trial and 29 completed. The baseline trough intraocular pressure (IOP) was 23.3+/-2.4 and the diurnal curve IOP was 22.0+/-1.3 mmHg. For the brimonidine and timolol maleate treatment group, the trough IOP was 21.6+/-3.3 and the diurnal curve IOP was 19.8+/-2.1 mmHg, while the timolol and unoprostone treatment showed a trough IOP of 20.9+/-3.8 and a diurnal curve IOP of 19.3+/-2.4 mmHg. There was no significant difference between treatment groups at any time point for the diurnal curve, or in the reduction from baseline (P>0.05). Both treatments failed to statistically reduce the IOP from baseline at 1800 h. There was no difference between treatment groups regarding ocular and systemic unsolicited adverse events, but patients admitted to more dryness (P=0.02) and burning upon instillation (P<0.0001) with unoprostone by survey.

CONCLUSION

Brimonidine 0.2% or unoprostone 0.15% added to timolol maleate 0.5% provide similar efficacy and safety throughout the daytime diurnal curve.

Efficacy and safety of the latanoprost/timolol maleate fixed combination vs concomitant brimonidine and latanoprost therapy

AIMS

To evaluate the efficacy and safety of latanoprost/timolol maleate fixed combination (LTFC) given once daily vs the concomitant therapy of brimonidine twice daily and latanoprost once daily in primary open-angle glaucoma or ocular hypertensive subjects.

METHODS

A prospective, double-masked, active-controlled comparison in which qualified subjects had all glaucoma medicines discontinued for 1 month and then were randomized to either LTFC or brimonidine and latanoprost concomitant therapy for 6 weeks. They were then switched to the other treatment regimen. The intraocular pressure (IOP) was measured at 0800, 1200, and 1600 h at baseline and at the end of Periods 1 and Period 2.

RESULTS

In 32 subjects, the diurnal curve of the untreated IOP of 26.0+/-3.4 decreased to 17.8+/-2.5 on LTFC and 17.2+/-2.8 mmHg on brimonidine and latanoprost (P=0.31). At 0800 and 1600 h, the IOPs were statistically similar between the groups (P>0.05). At 1200 h the latanoprost and brimonidine treatment IOP was statistically lower (16.2+/-3.2) than LTFC (18.0+/-2.8 mmHg). However, the reduced IOP from untreated baseline was not statistically different at each time point and for the diurnal curve for each therapy (P<0.05). Safety was similar between groups for both solicited and unsolicited side effects (P>0.05).

CONCLUSION

This study suggests that LTFC and concomitant therapy of brimonidine and latanoprost provide statistically similar diurnal IOP reduction from an untreated baseline.