Fixed combinations of dorzolamide-timolol and brimonidine-timolol in the management of glaucoma

Randomized Multicenter Clinical Trial Comparing 0.1% Brimonidine/0.5% Timolol Versus 1% Dorzolamide/0.5% Timolol as Adjuncts to Prostaglandin Analogues: Aibeta Crossover Study

INTRODUCTION

This multicenter, randomized, comparative, and investigator-masked crossover clinical trial sought to compare the efficacy and tolerability of fixed combinations of 0.1% brimonidine/0.5% timolol (BTFC) versus 1% dorzolamide/0.5% timolol (DTFC) as adjunctive therapies to prostaglandin analogues.

METHODS

A total of 110 patients with open-angle glaucoma or ocular hypertension previously treated with prostaglandin analogue monotherapy were randomized to receive either BTFC or DTFC as adjunctive therapy for 8 weeks. These patients were then crossed over to the alternative treatment arm for another 8 weeks. The reduction in intraocular pressure (IOP) (primary outcome), occurrence of adverse events, ocular discomfort after instillation, and patient preference (secondary outcomes) were recorded through patient interviews.

RESULTS

BTFC instillation for 8 weeks reduced IOP by 3.55 mmHg, demonstrating non-inferiority to DTFC instillation (3.60 mmHg; P < 0.0001, mixed-effects model). Although adverse events were rare with both combinations, patients reported greater discomfort with DTFC than with BTFC (P < 0.0001). More patients preferred BTFC (P < 0.0001) over DTFC, as BTFC caused minimal or no eye irritation.

CONCLUSION

As BTFC offered better tolerability than DTFC with comparable reduction in IOP, we recommend it as an alternative for patients who experience ocular discomfort with DTFC-prostaglandin analogue combination therapy.

TRIAL REGISTRATION NUMBER

jRCTs051190125.

Ocular Distribution of Brimonidine and Brinzolamide after Topical Instillation of a 0.1% Brimonidine Tartrate and 1% Brinzolamide Fixed-Combination Ophthalmic Suspension: An Interventional Study

PURPOSE

To evaluate the concentrations of brimonidine and brinzolamide in the vitreous and aqueous humor after instillation of a 0.1% brimonidine tartrate and 1% brinzolamide fixed-combination ophthalmic suspension.

METHODS

The present investigation involved patients with macular holes or idiopathic epiretinal membranes who were planning to undergo vitrectomy. One week prior to surgery, the patients received twice-daily topical treatment with 0.1% brimonidine tartrate and 1% brinzolamide fixed-combination ophthalmic suspension. Before vitrectomy, vitreous and aqueous humor samples were collected, and the mean concentrations of brimonidine and brinzolamide were determined through liquid chromatography-tandem spectrometry.

RESULTS

Ten eyes (nine phakic and one pseudophakic eyes; 10 patients) were examined. The concentration of brimonidine in vitreous and aqueous humor samples was 5.02 ± 2.24 and 559 ± 670 nM, respectively. The concentration of brimonidine in the vitreous humor, which is needed to activate α2 receptors, was >2 nM in all patients. The concentration of brinzolamide was 8.96 ± 4.65 and 1100 ± 813 nM, respectively. However, there was no significant correlation between the concentrations of brimonidine in the vitreous and aqueous humor samples.

CONCLUSIONS

Sufficient concentrations of brimonidine were detected in all vitreous samples. The dissociated correlation of the drug concentrations between aqueous and vitreous humors implies the possibility of another pathway to vitreous humor, different from the pathway to aqueous humor.

Fixed versus Unfixed Combination of Topical Latanoprost/Timolol for Glaucoma: An Observational Study Investigating the Level of Adherence and Ocular Surface Health

PURPOSE

To investigate the effect of fixed combination versus concomitant unfixed topical glaucoma treatment on patients' adherence and ocular surface health.

PATIENTS AND METHODS

This is a 6-month, prospective, parallel-group, observational study in patients with ocular hypertension (OHT), primary open-angle glaucoma (POAG), or exfoliation glaucoma (XFG). A total of 142 patients with similar baseline characteristics were enrolled in this study. Seventy-one patients received a Latanoprost 0.005%/Timolol 0.5% fixed combination in the evening, whereas seventy-one patients received the unfixed treatment with Latanoprost 0.005% in the evening and Timolol 0.5% twice daily. The primary outcome was the adherence rate at baseline, and at the 3- and 6-month follow-up visits. The secondary outcomes included the signs of ocular surface disease (OSD) and intraocular pressure (IOP).

RESULTS

The adherence of patients treated with the fixed combination was higher than the unfixed treatment at the 3-month (78.0% vs. 63.0%, p < 0.001) and at the 6-month visits (73.0% vs. 58.5%, p < 0.01). The Break-up Time, Schirmer test, and Van Bijsterveld score were worse in the unfixed group at baseline and all subsequent examinations (p < 0.05 for all comparisons). There were no differences in the mean IOP between groups at baseline, 1-, and 3-month visits. IOP appears higher in the unfixed group at 6 months (16.7 vs. 15.0 mmHg, p < 0.01).

CONCLUSION

The patients with ocular hypertension and primary open-angle glaucoma treated with a fixed combination are significantly more adherent and show a healthier ocular surface than those treated with an unfixed combination. The study provides significant evidence of the benefits of fixed combination treatment.

Brimonidine and timolol concentrations in the human vitreous and aqueous humors after topical instillation of a 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution: An interventional study

PURPOSE

To evaluate the concentrations of brimonidine and timolol in the vitreous and aqueous humors after instillation of a 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution.

METHODS

This single-arm open-label interventional study included patients with macular holes or idiopathic epiretinal membranes who were scheduled for vitrectomy. Written informed consent was obtained from all participants. A 0.1% brimonidine tartrate and 0.5% timolol fixed-combination ophthalmic solution was administered topically twice daily for 1 week preoperatively. The vitreous and aqueous humors were sampled before vitrectomy, and brimonidine and timolol concentrations were quantified using liquid chromatography-tandem spectrometry. This study was registered with the Japan Registry of Clinical Trials (jRCT, ID jRCTs051200008; date of access and registration: April 28, 2020). The study protocol was approved by the University of Fukui Certified Review Board (CRB) and complied with the tenets of the Declaration of Helsinki.

RESULTS

Eight eyes of eight patients (7 phakic eyes and 1 pseudophakic eye) were included in this study. The mean brimonidine concentrations in the vitreous and aqueous humors were 5.04 ± 4.08 nM and 324 ± 172 nM, respectively. Five of the eight patients had brimonidine concentrations >2 nM in the vitreous humor, which is necessary to activate α2 receptors. The mean timolol concentrations in the vitreous and aqueous humors were 65.6 ± 56.0 nM and 3,160 ± 1,570 nM, respectively. Brimonidine concentrations showed significant positive correlations with timolol concentrations in the vitreous humor (P < 0.0001, R2 = 0.97) and aqueous humor (P < 0.0001, R2 = 0.96).

CONCLUSIONS

The majority of patients who received a 0.1% brimonidine tartrate and 0.5% timolol topical fixed-combination ophthalmic solution showed a brimonidine concentration >2 nM in the vitreous humor. Brimonidine and timolol may be distributed in the ocular tissues through an identical pathway after topical instillation.

Dorzolamide/Timolol Fixed Combination: Learning from the Past and Looking Toward the Future

The key clinical attributes of preserved dorzolamide/timolol fixed combination (DTFC) and the emerging potential of preservative-free (PF) DTFC are reviewed with published evidence and clinical experience. The indications and role of DTFC in current glaucoma management are critically discussed. Preserved DTFC became the first intraocular pressure (IOP)-lowering fixed combination (FC) approved by the US Food and Drug Administration (FDA) and remains one of most commonly used medications worldwide. The pharmacological properties of DTFC reflect those of its two time-tested constituents, i.e., the carbonic anhydrase inhibitor dorzolamide and the non-selective beta-blocker timolol. In regulatory studies DTFC lowers IOP on average by 9 mmHg (32.7%) at peak and by 7.7 mmHg (27%) at trough. In trials DTFC shows equivalence to unfixed concomitant therapy, but in real-life practice it may prove superior owing to enhanced convenience, elimination of the washout effect from the second drop, improved tolerability, and better adherence. PF DTFC became the first PF FC approved, first in unit-dose pipettes, and more recently in a multidose format. Cumulative evidence has confirmed that PF DTFC is at least equivalent in efficacy to preserved DTFC and provides a tangible clinical benefit to patients with glaucoma suffering from ocular surface disease by improving tolerability and adherence. Finally, we identify areas that warrant further investigation with preserved and PF DTFC

Can dorzolamide/timolol-fixed combination effectively treat primary open-angle glaucoma?: A protocol for systematic review and meta-analysis

BACKGROUND

Primary open-angle glaucoma (POAG) is a very common disorder, and it is the second leading cause that results in blindness worldwide after cataracts. Previous studies have reported that dorzolamide/timolol-fixed combination (DTFC) can be used in treating POAG. However, there are still inconsistent results. Thus, this study will systematically investigate the efficacy and safety of DTFC on POAG.

METHODS

A comprehensive search will be carried out in Cochrane Library, MEDLINE, EMBASE, CINAHI, ACMD, China National Knowledge Infrastructure, and WANGFANG database from origin to the present. There are no limitations related to the language and publication status. Only randomized controlled trials that assessed the efficacy and safety of DTFC for the treatment of POAG will be included. Two researchers will independently undertake record selection, data extraction, and study quality assessment. Any divisions will be solved by discussion with a third researcher. We will perform statistical analysis using RevMan 5.3 software RESULTS:: This study will summarize the present evidence to identify the efficacy and safety of DTFC in treating POAG through mean intraocular pressure, best corrected visual acuity, contrast sensitivity, bioelectric activity of the retina, rate of progression of glaucoma, quality of life, and adverse events.

CONCLUSIONS

The results of this study will provide evidence of DTFC for the treatment of POAG.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202040120.

Fixed-combination topical anti-hypertensive ophthalmic agents

INTRODUCTION

Fixed-combination glaucoma medications have altered the paradigm of ocular hypertension and glaucoma treatment and are in widespread use today. A comprehensive review of fixed-combination medications will help educate and inform providers for optimal patient care.

AREAS COVERED

In this review, the authors describe the composition, mechanism of action, efficacy, side effects, and safety profile of fixed-combination agents for the treatment of ocular hypertension and glaucoma as well as comparisons between the most frequently prescribed medications.

EXPERT OPINION

Fixed-combination therapeutics provide an effective and efficient means of lowering intraocular pressure with comparable side effects and outcomes to constituent parts with lower patient exposure to preservatives and improvement in compliance.

Efficacy of the combination of carteolol hydrochloride + latanoprost in the treatment of glaucoma and ocular hypertension

INTRODUCTION

The only evidence-based mechanism for prevention and treatment of glaucomatous optic neuropathy is decreasing the intraocular pressure (IOP). Prescribing multiple ocular hypotensive agents, such as the combination of carteolol and latanoprost, may synergistically improve IOP; however, doing so may increase the complexity of a medication regimen, in turn, impairing patient adherence. Fixed-combination glaucoma medications offer convenience and effectiveness. New to this class of glaucoma medication is fixed combination carteolol-latanoprost (FCCL). Area covered: This review intends to give the reader a better understanding of the efficacy of the combination of carteolol and latanoprost separately, and where FCCL fits into the vast medical arsenal of IOP drops. Furthermore, it outlines the particular pharmacologic mechanisms targeted, the pharmacokinetics, effectiveness, the advantages of fixed-combination administration, and tolerability. Expert opinion: The combination of carteolol and latanoprost, separately or in a fixed-combination, is more effective than either drug alone. Given the early stage in development of FCCL, it has yet to be determined how FCCL compares to other fixed-combination medications. However, pending further approval, fixed-combination carteolol-latanoprost may represent a reasonable alternative for a patient whose IOP is inadequately controlled on a prostaglandin analog alone and for whom a simplified combination is preferred.

A 4-year retrospective study of add-on therapy to the fixed combination of dorzolamide/timolol for the treatment of POAG

AIM

To evaluate the long-term response to the fixed combination of dorzolamide/timolol in patients with primary open angle glaucoma (POAG) and the addition of other intraocular pressure (IOP) lowering medications such as prostaglandin analogs and brimonidine.

METHODS

A retrospective, non-randomized, and descriptive clinical study was performed with 182 eyes diagnosed with POAG. Patients were divided into three groups: a group with fixed combination of dorzolamide/timolol only, a second group with prostaglandin analogs plus fixed combination of dorzolamide/timolol, and a third group with the addition of brimonidine to the same fixed combination. IOP data were gathered retrospectively and the differences between groups were calculated.

RESULTS

IOP was reduced satisfactorily in all three groups; however, a progressive IOP reduction was noted in the group with the fixed combination plus prostaglandin analogs. In this group, a progressive, significant and more homogeneous response of the reduction was noted in comparison with the other groups.

CONCLUSION

IOP reduction was efficacious in all three groups. The addition of prostaglandin analogs showed progressive IOP reduction, progressive response and absence of long-term drift. Brimonidine did not show a significant additive effect.

Efficacy and tolerability of the fixed combinations latanoprost/timolol versus dorzolamide/timolol in patients with elevated intraocular pressure: a meta-analysis of randomized controlled trials

Objective

To evaluate the efficacy and tolerability of the fixed combination of Latanoprost/Timolol versus Dorzolamide/Timolol in the treatment of patients with elevated intraocular pressure (IOP).

Methods

A comprehensive literature meta-analysis was performed according to the Cochrane Collaboration methodology to identify randomized clinical trials comparing latanoprost/timolol FC (FCLT) with dorzolamide/timolol (FCDT) in patients with elevated IOP. The efficacy estimates were measured by the weight mean difference (WMD) for the IOP reduction (IOPR) from baseline to end point, including the diurnal mean IOPR, 8 AM IOPR, 12 PM IOPR, and 4 PM IOPR. The tolerability estimates were measured by RR for adverse events. All outcomes were reported with a 95% confidence interval (CI). The data were synthesized by Stata 12.0 SE for Windows.

Results

Eight studies involving 841 patients (841 eyes) were included in the meta-analysis. With a WMD of IOPR in the diurnal mean of 0.16 mmHg (95% CI, -0.31 to 0.63), the FCLT was as effective as FCDT in lowering IOP in patients with elevated IOP (P = 0.51). The WMDs of IOPR were 0.58 mmHg (95% CI: -0.002 to 1.17) at 8 AM, -0.07 mmHg (95% CI: -0.50 to 0.36) at 12 PM, and 0.41 mmHg (95% CI: -0.18 to 1.00) at 4 PM, and there were no significant difference between FCLT and FCDT. FCLT was associated with a significantly lower incidence of eye pain, bitter taste, and irritation/stinging than FCDT, with pooled RRs of 0.34 (95% CI: 0.14 to 0.82), 0.06 (95% CI:0.008 to 0.42), and 0.35 (95% CI: 0.14 to 0.85), respectively.

Conclusion

FCLT was associated with equivalent efficacy in IOP lowering comparing with FCDT. However, FCLT was better tolerated than FCDT.

Efficacy and tolerability of fixed combination of brimonidine 0.2%/timolol 0.5% compared with fixed combination of dorzolamide 2%/timolol 0.5% in the treatment of patients with elevated intraocular pressure: a meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the efficacy and tolerability of the fixed-combination brimonidine 0.2%/timolol 0.5% (FCBT) compared with the fixed-combination dorzolamide 2%/timolol 0.5% (FCDT) in the treatment of patients with elevated intraocular pressure (IOP).

METHODS

Pertinent randomized controlled trials comparing FCBT with FCDT in patients with elevated IOP were identified through systematic searches of the Cochrane Library, PubMed, and EMBASE. The main efficacy measures were the IOP reduction (IOPR), including diurnal mean IOPR, and peak IOPR. The main tolerability measure was the individual adverse events. The pooled estimates and 95% confidence intervals (CIs) were carried out in RevMan version 5.0 software.

RESULTS

Seven studies involving 582 patients were included in the meta-analysis. With a weighted mean difference (WMD) of IOPR in diurnal mean of 0.44 mmHg (95% CI, 0.00-0.88), the FCBT was as effective as FCDT in lowering IOP in patients with elevated IOP (P=0.05). The WMD of IOPR at peak was 0.65 mmHg (95% CI, -0.06 to 1.35) (P=0.76), and there was no significant difference between FCBT and FCDT. FCBT caused burning/stinging in less patients than FCDT [pooled relative risk: 0.45 (95% CI, 0.29-0.70)].

CONCLUSIONS

Both FCBT and FCDT can effectively lower IOP in patients with elevated IOP, and the IOP-lowering efficacy of FCBT is noninferior to that of FCDT. Additionally, FCBT affords an ocular comfort advantage compared with FCDT.

Meta-analysis of α2-adrenergic agonists versus carbonic anhydrase inhibitors as adjunctive therapy

OBJECTIVE

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).

RESEARCH DESIGN AND METHODS

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.

MAIN OUTCOME MEASURES

The main efficacy measures were the reduction from baseline to end of treatment in IOP at peak, trough, and diurnal curve.

RESULTS

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.

Twenty-four hour efficacy with the dorzolamide/timolol-fixed combination compared with the brimonidine/timolol-fixed combination in primary open-angle glaucoma

AIM

The aim of this study is to compare the 24-hour efficacy of dorzolamide/timolol-fixed combination (DTFC) and brimonidine/timolol-fixed combination (BTFC) in primary open-angle glaucoma (POAG).

METHODS

One eye each of 77 POAG patients was included in this prospective, observer-masked, crossover comparison. Following a 2-month timolol run-in period, patients had three intraocular pressure (IOP) measurements at 1000, 1200 and 1400 h while on timolol treatment. Patients showing at least a 20% IOP reduction on timolol were randomised to 3 months of therapy with DTFC or BTFC, and then were crossed over to the opposite therapy.

RESULTS

Sixty POAG patients completed the study. The mean 24-hour IOP was significantly reduced with both the fixed combinations compared with the timolol-treated diurnal IOP (P < 0.001). When the two fixed combinations were compared directly, DTFC demonstrated a lower mean 24-hour IOP level as compared with BTFC (mean difference: -0.7 mm Hg, 95% confidence interval (CI): (-1.0, -0.3), P < 0.001). At two individual time points, DTFC significantly reduced IOP more than BTFC: at 1800 h (-1.0 mm Hg, 95% CI (-1.6,-0.5), P = 0.001) and at 0200 (-0.9 mm Hg, 95% CI: (-1.4,-0.5), P = 0.001). No significant difference existed for the other time points.

CONCLUSION

Both the fixed combinations significantly reduce 24-hour IOP in POAG. DTFC provided significantly better 24-hour efficacy.

Update on the role of alpha-agonists in glaucoma management

Glaucoma is the second most common cause of world blindness (following cataract) with estimated cases reaching 79.6 million by 2020. Although the etiology of glaucoma is multi-factorial, intraocular pressure (IOP) is the only modifiable factor in glaucoma management proven to alter the natural course of the disease. Among various classes of IOP-lowering medications currently available, alpha-adrenergic receptor agonists are used either as monotherapy, as second-line therapy, or in fixed combination with beta-blockers. Non-selective adrenergic agonists such as epinephrine and dipivefrin are infrequently used today for the treatment of glaucoma or ocular hypertension, and have been replaced by the alpha-2-selective agonists. The use of apraclonidine for IOP reduction in glaucoma or OHT is limited due to a high rate of follicular conjunctivitis. The alpha-2-selective agonist in use today is brimonidine. The brimonidine-purite formulations are preferred to brimonidine-benzalkonium chloride (BAC) formulations due better tolerability while maintaining similar efficacy. Brimonidine is also effective when used in combination with a beta-blocker. Using brimonidine-timolol fixed combination (BTFC) as first-line therapy has an added potential for neuroprotection. This would be a valuable strategy for glaucoma treatment, for patients who are intolerant of prostaglandin analogs, or for patients where prostaglandin analogues are contraindicated as first-line therapy, such as in patients with inflammatory glaucoma.

Safety, tolerability, and efficacy of fixed combination therapy with dorzolamide hydrochloride 2% and timolol maleate 0.5% in glaucoma and ocular hypertension

Glaucoma is a collection of diseases characterized by multifactorial progressive changes leading to visual field loss and optic neuropathy most frequently due to elevated intraocular pressure (IOP). The goal of treatment is the lowering of the IOP to prevent additional optic nerve damage. Treatment usually begins with topical pharmacological agents as monotherapy, progresses to combination therapy with agents from up to 4 different classes of IOP-lowering medications, and then proceeds to laser or incisional surgical modalities for refractory cases. The fixed combination therapy with the carbonic anhydrase inhibitor dorzolamide hydrochloride 2% and the beta blocker timolol maleate 0.5% is now available in a generic formulation for the treatment of patients who have not responded sufficiently to monotherapy with beta adrenergic blockers. In pre- and postmarketing clinical studies, the fixed combination dorzolamide–timolol has been shown to be safe and efficacious, and well tolerated by patients. The fixed combination dorzolamide–timolol is convenient for patients, reduces their dosing regimen with the goal of increasing their compliance, reduces the effects of “washout” when instilling multiple drops, and reduces the preservative burden by reducing the number of drops administered per day.