The additive intraocular pressure-lowering effect of latanoprost 0.005% daily once and pilocarpine 2% t.i.d. in patients with open-angle glaucoma or ocular hypertension. a 6-month, randomized, multicenter study. German Latanoprost Study Group

Adjunctive Use of Tafluprost with Timolol Provides Additive Effects for Reduction of Intraocular Pressure in Patients with Glaucoma

Purpose

This study investigated the efficacy and safety of tafluprost as an adjunctive therapy to timolol in patients with open-angle glaucoma or ocular hypertension, uncontrolled by timolol monotherapy.

Methods

This was a randomized, double-masked, parallel-group, multinational and multicenter 12-week phase III study. Tafluprost 0.0015% (once daily: 20:10) or vehicle were administered as adjunctive therapy to timolol 0.5% (twice daily: 08:00 and 20:00) for 6 weeks, after which all patients received tafluprost for 6 weeks. Intraocular pressure (IOP) measurements were conducted at 08:00, 10:00, and 16:00 at baseline, and weeks 2, 4, 6, and 12.

Results

A total of 185 patients were randomized to tafluprost (n = 96) or vehicle (n = 89). Reductions in IOP were seen in both groups, which were consistently more pronounced with tafluprost. At week 6, the change from baseline in diurnal IOP ranged from −5.49 to −5.82 mm Hg, and the overall treatment difference (tafluprost vehicle) was −1.49 mmHg (upper 95% confidence interval, −0.66; p<0.001, intention-to-treat population, repeated measurements of the analysis of covariance model). At week 12, the change from baseline ranged from −6.22 to −6.79 mmHg in the tafluprost group. Patients switched from vehicle to tafluprost achieved a similar decrease in IOP to those who received tafluprost throughout the study (group difference at 12 weeks, −0.09 mmHg, p=0.812). There were more ocular adverse events with tafluprost compared with vehicle (42% vs. 29%, respectively), but most were mild in severity.

Conclusions

As adjunctive therapy to timolol, tafluprost achieved a consistently greater reduction in IOP compared with vehicle, and was well tolerated.

Impact of combination use of 0.004% travoprost and 2% pilocarpine on matrix metalloproteinases synthesized by rabbit ciliary muscle: a pilot study

OBJECTIVE

To explore the impact of combination use of prostaglandin analogue and cholinergic agonists on main matrix metalloproteinases (MMPs) synthesized by albino rabbit ciliary muscle.

METHODS

Normal adult albino rabbits were divided into the control group, 2% pilocarpine group, 0.004% travoprost group and travoprost plus pilocarpine group. Two rabbits in the control group were executed after treated with normal saline for one day. Two rabbits were separately executed on the 7th, 14th and 24th day of the treatment in each drug treated group. In each subgroup ciliary muscle band of 4 eyes was taken and made into homogenate. The MMPs activities of 10 subgroups were assayed by zymography. Bands' intensity which represents the activity of MMPs was measured by the UltraViolet Illumination system.

RESULTS

A bright band of MMP-1/2 was showed on each lane at the position corresponding to the molecular weight of 62 kD in the ciliary smooth muscles electrophoresis. When ion Zn and Ca was displaced by MMPs inhibitor EDTA, this bright band disappeared. Compared with the control group, MMP1/2 activity increased by 4.0%, 4.1% and 14.0% after 7, 14 and 24 days of pilocarpine treatment. Corresponding data was 23.2%, 61.7% and 111.5% in the travoprost group and 49.3%, 68.0% and 88.4% in the travoprost plus pilocarpine group.

CONCLUSIONS

Pilocarpine has little effect on activity of MMP1/2. Travoprost can increase activity of MMP1/2 gradually. Activity of MMP1/2 is rapidly increased by pilocarpine combined with travoprost, but shows small change with the prolonged treatment.

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.

Intraocular pressure-lowering combination therapies with prostaglandin analogues

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.

A review of the use of latanoprost for glaucoma since its launch

INTRODUCTION

Prostaglandins are increasingly used as first choice treatment for glaucoma because they are highly effective, lack relevant systemic side effects and require just once-daily administration. Latanoprost is an ester prodrug analog of prostaglandin F2α, which reduces intraocular pressure (IOP) by increasing uveoscleral outflow. Latanoprost 0.005% has received European and US approval as the first-line drug for reducing IOP in patients with open-angle glaucoma or ocular hypertension. Following the recent patent expiry for Xalatan®, a number of latanoprost generics have entered the glaucoma market.

AREAS COVERED

This review, achieved through PubMed and Medline research methods, describes the composition, pharmacokinetics, mode of action, efficacy, side effects and safety profile of latanoprost.

EXPERT OPINION

Latanoprost was the first prostaglandin analog introduced in glaucoma management and it dramatically changed the market of the disease thanks to its efficacy and safety. Conjunctival hyperemia, which is commonly found after latanoprost use, is associated with a minor efficacy and duration of trabeculectomy; yet, from the ophthalmologist's perspective, this side effect seems largely counterbalanced by the high efficacy and safety of this compound. It is always advisable to consider the pro-inflammatory mode of action of latanoprost because this may have negative effects in particular patients (i.e., those with uveitis and cystoid macular edema) for whom caution and close follow-up is necessary.

Efficacy of single glaucoma medication in combined latanoprost and timolol XE therapy in patients with open-angle glaucoma and ocular hypertension: a discontinuation study

PURPOSE

To study the effect of single drug discontinuation in combined timolol XE 0.5% and latanoprost 0.005% treatment.

METHODS

Fifty patients with open-angle glaucoma or ocular hypertension who had received both latanoprost and timolol XE for at least 6 months were enrolled in this study. Timolol XE and latanoprost were administered once daily, timolol XE in the morning and latanoprost in the evening. Twenty-five patients discontinued timolol XE and the remaining 25 patients discontinued latanoprost. Either latanoprost or timolol XE was discontinued and 8 weeks later it was resumed. A change in intraocular pressure (IOP) was studied.

RESULTS

All patients had complete follow-up visits. A significant increase in mean IOP was found following drug discontinuation in the 2 groups. Mean change in IOP 8 weeks after discontinuation of the drug was +1.6±1.2 mmHg (10.3%±8.0%) in the timolol XE group and +4.3±1.6 mmHg (+27.2%±11.8%) in the latanoprost group. The change in the latanoprost group was significantly greater compared with that in the timolol XE group (P<0.0001). There was no significant difference in mean IOP between before drug discontinuation and at 8 weeks after drug resumption in any group.

CONCLUSIONS

There was a significant increase in IOP from discontinuation of timolol XE and latanoprost. The hypotensive effect of latanoprost in the combined drug therapy is significantly greater compared with timolol XE.

Efficacy of single glaucoma drug in combined timolol XE, latanoprost and brinzolamide therapy: a discontinuation study

PURPOSE

To study the efficacy of a single drug in patients with primary open angle glaucoma and ocular hypertension who were receiving timolol XE 0.5%, latanoprost 0.005% and brinzolamide 1% with its discontinuation.

METHODS

Sixty patients with open-angle glaucoma or ocular hypertension who were administered timolol XE, latanoprost, and brinzolamide were studied. One drug consisting of timolol XE, brinzolamide, and latanoprost was discontinued and 8 weeks later, it was resumed. A change in intraocular pressure (IOP) was studied.

RESULTS

Mean IOP at baseline and at 8 weeks after discontinuation of each drug was 15.8 ± 1.3 and 17.3 ± 1.4 mmHg in the timolol XE group, 15.8 ± 1.0 and 20.0 ± 1.4 mmHg in the latanoprost group, and 16.0 ± 1.4 and 18.1 ± 1.4 mmHg, respectively. A significant increase in mean IOP was found after drug discontinuation (timolol XE: P = 0.0012; latanoprost: P<0.0001; brinzolamide: P<0.0001). The mean change in IOP by discontinuation of the drug was +1.6 ± 0.9 mmHg (+9.6% ± 5.6%) in the timolol XE group, +4.3 ± 1.7 mmHg (27.4% ± 12.4%) in the latanoprost group, and +2.2 ± 0.9 mmHg (+13.7% ± 6.1%) in the brinzolamide group. The change in the latanoprost group was significantly greater compared with those in the timolol XE and brinzolamide groups (timolol XE: mmHg and percent: P<0.0001; brinzolamide: mmHg and percent: P<0.0001). The IOP change in the brinzolamide group was significantly greater than that in the timolol XE group (mmHg: P = 0.0417; percent: P = 0.0328). No significant difference was observed in mean IOP between before drug discontinuation and at 8 weeks after drug resumption in any group.

CONCLUSIONS

There was a significant increase in IOP from discontinuation of timolol XE, latanoprost, and brinzolamide in the multiple drug treatment. The hypotensive effect of latanoprost in the combined drug therapy is significantly greater than the effects of timolol XE and brinzolamide.

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.

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.

Intraocular Pressure–Lowering Effect of Adding Dorzolamide or Latanoprost to Timolol

OBJECTIVE

To estimate the intraocular pressure (IOP)-lowering effect of 2% dorzolamide or 0.005% latanoprost when added to 0.5% timolol.

DESIGN

Meta-analysis of randomized clinical trials.

PARTICIPANTS

Seventeen articles reporting on 19 study arms with 5 possible treatment combinations and 4 study arms serving as controls.

METHODS

Articles written in English, German, French, or Dutch and published up to December 2004 were identified in Medline, Embase, the Cochrane Controlled Trials Register, and references from relevant articles. For the article to be considered, over 85% of the patients had to have primary open-angle glaucoma or ocular hypertension. The pooled 1- to 3-month additional IOP-lowering effect after a run-in phase on timolol was calculated by performing meta-analysis using the random effects model.

MAIN OUTCOME MEASURES

Absolute and relative changes in IOP after run-in on timolol for peak moment, trough moment, or mean diurnal curve.

RESULTS

The pooled change from baseline [mean (95% confidence interval)] for 0.5% timolol varied from -0.7 mmHg (-1.2 to -0.2, for the mean diurnal curve) to -2.0 mmHg (-1.3 to -2.7, at peak). Pooled changes for 2% dorzolamide in concomitant use with 0.5% timolol were -4.1 mmHg (-4.4 to -3.8) at trough and -4.9 mmHg (-5.3 to -4.5) at peak. The fixed 2% dorzolamide and 0.5% timolol combination resulted in a pooled change of -3.8 mmHg (-4.2 to -3.4) at trough and -4.9 mmHg (-5.3 to -4.5) at peak. The concomitant use of 0.005% latanoprost and 0.5% timolol gave a pooled change from baseline of -6.0 mmHg (-6.8 to -5.2) at the mean diurnal curve. The fixed combination of 0.005% latanoprost and 0.5% timolol resulted in a mean change of -3.0 mmHg (-3.8 to -2.2) at the mean diurnal curve.

CONCLUSION

In this meta-analysis of clinical trials, the addition of dorzolamide or latanoprost further lowers IOP in eyes on timolol. This result may not be generalizable because these trials may have included nonresponders to timolol.

Latanoprost : an update of its use in glaucoma and ocular hypertension

Latanoprost (Xalatan) is an ester analogue of prostaglandin F2alpha that reduces intraocular pressure (IOP) by increasing uveoscleral outflow. The IOP-lowering efficacy of latanoprost 0.005% lasts for up to 24 hours after a single topical dose, which allows for a once-daily dosage regimen. In patients with ocular hypertension or open-angle glaucoma, a single drop of latanoprost 0.005% solution (about 1.5 microg) administered topically once daily reduced diurnal IOP by 22 to 39% over 1 to 12 months' treatment in well-controlled trials; efficacy was maintained during treatment periods of up to 2 years. At this dosage, latanoprost was significantly more effective than timolol 0.5% twice daily in 3 of 4 large, double-blind, randomised studies, was generally as effective as bimatoprost or travoprost, and was significantly more effective than dorzolamide, brimonidine or unoprostone. Furthermore, in patients whose IOP was poorly controlled with timolol, switching to latanoprost monotherapy was at least as effective at lowering IOP as adding dorzolamide or pilocarpine to the regimen. Latanoprost has also shown significant additive effects when used in combination with one or more other glaucoma medications. The fixed combination of latanoprost plus timolol was significantly more effective than either of its individual components in two double-blind randomised studies and more effective than the fixed combination of dorzolamide and timolol in a 3-month, evaluator-masked study. Data in patients with angle-closure glaucoma are limited, but in patients with elevated IOP after undergoing iridotomy, latanoprost 0.005% once daily was significantly more effective than timolol 0.5% twice daily at reducing IOP over 12 weeks of treatment in a large double-blind, randomised study. Latanoprost is generally well tolerated and, unlike timolol, induces minimal systemic adverse events. In well-controlled, 6-month trials, the most commonly occurring drug-related ocular events in latanoprost recipients were mild to moderate conjunctival hyperaemia (3 to 15%) and iris colour change (2 to 9%); these seldom required patient withdrawal although the latter may be permanent. Latanoprost 0.005% as a single daily drop has shown good IOP-lowering efficacy in patients with open-angle glaucoma or ocular hypertension and does not produce the cardiopulmonary adverse effects associated with beta-blockers. Thus, latanoprost is a valuable addition to the first-line treatment options for patients with open-angle glaucoma or ocular hypertension. In addition, adjunctive treatment with latanoprost in patients who are refractory to beta-blocker therapy is a viable, second-line treatment option. Although preliminary findings are promising, wider clinical experience is required to define the place of latanoprost in the treatment of angle-closure glaucoma.

Current status of prostaglandin therapy: latanoprost and unoprostone

Latanoprost, a prostaglandin F(2alpha) analog prodrug, and unoprostone, an analog of a prostaglandin metabolite, have been shown to be effective in decreasing intraocular pressure when used alone or in combination with other ocular hypotensive agents. The increase in the uveoscleral outflow and some of the side effects are probably FP-receptor mediated, which may account for some differences between the cited drugs. This article reviews the recent literature available on the clinical efficacy of these prostanoids, as well as the studies directly comparing these drugs.

Combined therapy of pilocarpine or latanoprost with timolol versus latanoprost monotherapy

Adjunctive intraocular pressure (IOP)-lowering therapy is widely used today, as one-third of all patients being treated for glaucoma need additional therapy to reach and maintain healthy IOPs. Timolol, latanoprost, and pilocarpine are three potent drugs that have been used in combination to reduce IOP. Timolol reduces the production rate of aqueous humor to achieve the IOP decrease. Latanoprost and pilocarpine both affect aqueous outflow, although by different mechanisms. The IOP efficacy of combined therapy with timolol and pilocarpine compared with timolol and latanoprost or with latanoprost alone has been investigated in three multicenter, randomized, clinical trials in Europe. This is a review of those published trials. In 2 of the 3 studies, the additional IOP lowering effect of latanoprost 0.005% administered once daily was compared with pilocarpine 2% administered 3 times daily in patients with primary open-angle glaucoma (POAG) or ocular hypertension currently on monotherapy with timolol 0.5% twice daily. These 6-month studies found that the timolol and latanoprost combination reduced IOP more and was better tolerated with fewer side-effects than the timolol and pilocarpine combination. At 6 months, there was no evidence of long-term drift in IOP with timolol and latanoprost. This combined therapy provides an effective and safe option for lowering IOP in glaucoma patients. These results suggest that the timolol/latanoprost combination is preferable to the timolol/pilocarpine combination not only with regard to side effects but also to the magnitude of IOP reduction. Two of the 3 studies compared latanoprost monotherapy with timolol and pilocarpine combined therapy in patients with POAG, various other glaucomas, or ocular hypertension. Treatment was for 6 weeks or 6 months. In both studies, latanoprost was more effective and better tolerated than the combination of timolol and pilocarpine. These results suggest that latanoprost alone should be tried before the addition of pilocarpine to timolol therapy is considered. The convenience of daily administration of a single drop of latanoprost versus multiple drops of timolol and pilocarpine should improve patient compliance.

Additive effect of unoprostone and latanoprost in patients with elevated intraocular pressure

AIMS

To assess the additive effect of unoprostone and latanoprost in patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT) METHODS: 32 patients with POAG or OHT were randomised to receive either latanoprost once daily or unoprostone twice daily for 4 weeks. After 4 weeks, all patients received both latanoprost and unoprostone for another 4 weeks. The IOP was measured at 9 am and 5 pm on the baseline, day 28, and day 56 visits, and at 9 am on day 14 and day 42 visits. The medications were given to the patients in an open label fashion. The observer was masked to the treatment given. The mean of the measurements was calculated. Safety parameters were also recorded. The additive effect of the medications was assessed by the reduction in intraocular pressure (IOP) when both medications were used, compared with when one medication was used.

RESULTS

28 patients completed both treatment periods and had IOP data available for evaluation. After 1 month of treatment, latanoprost significantly reduced IOP (mean by 6.1 (SEM 0.8) mm Hg (p<0.001) and unoprostone by 4.9 (1.0) mm Hg (p<0.001) from the baseline of 24.4 (0.6) mm Hg and 24.4 (1.1) mm Hg respectively (p = 0.18). When latanoprost once daily was given to patients treated with unoprostone, there was additional IOP lowering of 1.9 (0.6) mm Hg (p = 0.012). However, adding unoprostone to those being treated with latanoprost produced an IOP change of +0.4 (0.5) mm Hg (p = 0.42). Ocular symptoms and findings were mild and equally distributed between treatment groups, and after combined therapy. Hyperaemia and ocular irritation were the most frequently reported events. Over a third of patients experienced ocular irritation with the combination of medications.

CONCLUSIONS

Latanoprost once daily causes additional IOP lowering in eyes which were being treated with unoprostone twice a day. However, there was no additional IOP lowering when unoprostone was added to eyes which were being treated with latanoprost. Both drugs were well tolerated together with few ocular adverse events.

The pros and cons of different prostanoids in the medical management of glaucoma

The prostaglandin analogs are new exciting drugs added to the therapeutic armamentarium for patients with glaucoma. Several studies have evaluated the ocular hypotensive properties and side effects of latanoprost in different forms of glaucoma. This drug, seems to be the most effective intraocular pressure (IOP)-reducing agent currently available, and has a low incidence of ocular and systemic side effects. Fewer data are available regarding unoprostone, but the IOP-reducing effect of this drug seems to be comparable or slightly inferior to that of timolol and it produces fewer side effects. When compared with unoprostone, latanoprost has been shown to effect a greater reduction in IOP. A major drawback to the use of prostaglandin analogues is the lack of long-term experience such as that currently available for other classes of agents.