Fixed-combination topical anti-hypertensive ophthalmic agents

A novel fixed-combination timolol-netarsudil-latanoprost ophthalmic solution for the treatment of glaucoma and ocular hypertension

Currently commercial fixed-concomitant three agents have multiple problems such as multiple dosing administration, poor efficacy and side effects. Once-daily fixed-combination timolol-netarsudil-latanoprost ophthalmic solution (FC-TNL) has the ability to treat glaucoma by lowering the intraocular pressure (IOP) with great efficacy and improving patient compliance. However, the commercialized netarsudil dimesylate precipitated when the pH of the solution was above 5.4, or when maleic acid, the salt of commercial timolol maleate, was mixed with netarsudil dimesylate. Consequently, the homologous salt engineering strategy was used to make netarsudil dimesylate soluble in pH 4.8-5.2 solution by synthesizing timolol mesylate. Next, the morphology of timolol mesylate was observed by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and powder X-ray diffraction. The prepared FC-TNL showed good stability during refrigeration storage. Additionally, FC-TNL exerted no influence on the intraocular penetration of each active compounds in the pharmacokinetic study. Importantly, once-daily FC-TNL exerted potent IOP-lowering effect and protective effect on retinal ganglion cells. The FC-TNL was stable, safe and effective, being a promising glaucoma therapeutic.

Triple Fixed-Combination Bimatoprost/Brimonidine/Timolol in Glaucoma and Ocular Hypertension in India: A Multicenter, Open-Label, Phase 3 Study

Introduction

To evaluate the intraocular pressure (IOP)-lowering efficacy and safety of a triple fixed-combination of bimatoprost, brimonidine, and timolol (TFC) in patients with glaucoma or ocular hypertension (OHT) treated with fixed-combination or unfixed brimonidine and timolol therapy (dual-combination therapy).

Methods

In this multicenter, open-label, phase 3 study, patients who received 4-8 weeks of dual-combination therapy twice daily and had an IOP >18 and <34 mmHg in at least one eye were switched (at baseline) to treatment with TFC twice daily for 12 weeks. At Weeks 4, 8, and 12 on TFC, IOP was assessed at Hours 0, 2, and 8. Primary efficacy variable: mean diurnal IOP change from baseline in the study eye at Week 12 (modified intent-to-treat [mITT] population). Sensitivity (per-protocol [PP] population) and subgroup (≤65 vs >65 years) analyses were performed. Safety, including adverse events (AEs), was assessed at each visit.

Results

Of 126 patients enrolled, 121 and 103 formed the mITT/safety and PP populations, including 109 (90.1%) and 94 (91.3%) who completed the study, respectively. In the mITT/safety population, mean age was 58.6 years. Patients had open-angle glaucoma (51.2%), angle-closure glaucoma with patent iridotomy (36.4%), and/or OHT (13.2%). At Week 12, the mean diurnal change in IOP from dual combination-treated baseline was statistically significant (P<0.001) with TFC in the mITT (-3.98 mmHg) and PP (-4.22 mmHg) populations. Results were similar at all visits, regardless of the age subgroup. The most frequent treatment-related AEs were conjunctival hyperemia (14.0%) and dry eye (4.1%); 5.8% of the patients discontinued treatment due to ocular AEs.

Conclusion

TFC offers a beneficial therapeutic alternative for patients with glaucoma or OHT whose IOP is not sufficiently controlled with dual-combination therapy. Safety and efficacy findings support those of published studies of TFC in primary open-angle glaucoma and OHT, despite differences in study designs.

The use of fixed dose drug combinations for glaucoma in clinical settings: a retrospective, observational, single-centre study

BACKGROUND

The aim of study was to understand anti-glaucoma fixed dose drug combination use in real-world settings, focussing on drug selection, repeated prescription of the same active ingredient, and administration of fixed dose combinations, thus providing a reference for doctors during prescription and pharmacists during prescription review, ultimately educating patients on medication.

METHODS

A retrospective, observational, single-centre study was conducted. Outpatient prescriptions for anti-glaucoma eye drops from 01 January to 31 March 2021 were extracted. The prescriptions containing anti-glaucoma fixed dose combinations were analysed, and the rationale for each prescription was reviewed.

RESULTS

There were 10,947 ophthalmic patients with anti-glaucoma eye drop prescriptions in the study period. Of these, 4002 (36.5%) were prescribed anti-glaucoma fixed dose drug combinations. Approximately 80% of the patients were prescribed brinzolamide/timolol, while about 10% received prostaglandin analogues/timolol eye drops. Less than 40% of prescriptions were for monotherapy with fixed dose combinations. The most commonly duplicated drug class was β-receptor antagonists. An increase in prescribing drugs containing the same ingredient was observed for regimens containing various medicines.

CONCLUSION

More than 60% of the combinations were used together with other anti-glaucoma drugs. The advantages of these fixed dose combinations in improving patient compliance need to be reassessed in real-word settings. Prescriptions containing duplicated ingredients were common. However, they were not necessarily considered unreasonable because the dosage forms were administered at different times. For prescriptions containing repetitive ingredients, pharmacists should judge the rationale by evaluating the dosing frequency and drug indications and explain the appropriate administration to patients.

Assessment of the safety of intravitreal injection of metoprolol tartrate in rabbits

PURPOSE

To verify the safety of different doses of intravitreal metoprolol tartrate (MT) after intravitreal injection in rabbit eyes.

METHODS

Animals were randomly assigned into 2 groups: group I received 50 µg of MT and group II 100 µg of MT. A volume of 0.05 mL of the drug solution was administered through an intravitreal injection, while the control eyes received an equal volume of saline solution. Safety was assessed by clinical observation, electroretinography (ERG) and histological evaluation.

RESULTS

No evidence of clinical toxicity was observed. ERG waveforms from the MT treated eyes were similar to those recorded from the control eyes in dark-adapted state, amplitude and the implicit time are similar between the groups in light-adapted state, and their retinas had no signs of toxicity by histological evaluation 7 days after intravitreal injection.

CONCLUSIONS

The intravitreal use of metoprolol at 50 and 100 µg dosages does not cause short-term retinal toxicity in rabbits.

Current and new pharmacotherapeutic approaches for glaucoma

INTRODUCTION

Glaucoma is the leading cause of irreversible blindness worldwide. Medical therapy is the main line of treatment of open-angle glaucoma (OAG) and ocular hypertension. Despite the expansion of the glaucoma lineup with the newly approved medication classes, many barriers and issues still exist with topical therapy. Novel non-topical drug delivery may address such issues, adding more options to glaucoma pharmacotherapy.

AREAS COVERED

This review outlines current topical therapies for glaucoma, in addition to new medications under trials. The issues with topical therapy, in general, are discussed, as well as the new non-topical drug delivery systems. The authors performed a comprehensive search for published studies on glaucoma medical therapy using the electronic database of PubMed and manual search for each medication and non-topical delivery options. The extra- and intraocular delivery methods and the new topical glaucoma medications under research are covered.

EXPERT OPINION

Medical management of glaucoma represents a challenge for both patients and clinicians. Noncompliance (e.g. difficulty with administering the eye drops), cost, side effects, and intraocular pressure fluctuation are the major problems with topical therapy. To overcome such barriers, research should continue in developing new medications and innovation of non-topical drug delivery systems.