Cardiovascular and respiratory considerations with pharmacotherapy of glaucoma and ocular hypertension

Alternatives to Topical Glaucoma Medication for Glaucoma Management

Topical glaucoma medications have favorable safety and efficacy, but their use is limited by factors such as side effects, nonadherence, costs, ocular surface disease, intraocular pressure fluctuations, diminished quality of life, and the inherent difficulty of penetrating the corneal surface. Although traditionally these limitations have been accepted as an inevitable part of glaucoma treatment, a rapidly-evolving arena of minimally invasive surgical and laser interventions has initiated the beginnings of a reevaluation of the glaucoma treatment paradigm. This reevaluation encompasses an overall shift away from the reactive, topical-medication-first default and a shift toward earlier intervention with laser or surgical therapies such as selective laser trabeculoplasty, sustained-release drug delivery, and micro-invasive glaucoma surgery. Aside from favorable safety, these interventions may have clinically important attributes such as consistent IOP control, cost-effectiveness, independence from patient adherence, prevention of disease progression, and improved quality of life.

Psychometric Evaluation of Glaucoma Quality of Life Item Banks (GlauCAT) and Initial Assessment Using Computerized Adaptive Testing

Purpose

To evaluate the psychometric properties of glaucoma-specific quality of life (QoL) item banks (GlauCAT) and assess their performance using computerized adaptive testing (CAT) simulations.

Methods

In this cross-sectional study, 293 participants with glaucoma (mean age ± SD, 70.7 ± 13.2 years; 45% female) answered 342 items in 12 QoL item banks (IBs): Activity Limitation (AL); Driving (DV); Convenience (CV); Economic (EC); Emotional (EM); General Symptoms (GS); Health Concerns (HC); Lighting (LT); Mobility (MB); Ocular Surface Symptoms (OS); Social (SC); and Visual Symptoms (VS). These IBs were assessed using Rasch analysis, and CAT simulations with 1000 simulated respondents were utilized to determine the average number of items to be administered to achieve moderate and high precision levels.

Results

The AL, DV, EM, HC, LT, MB, EC, OS, SC, and VS IBs required relatively minor amendments to achieve satisfactory psychometric fit. To resolve multidimensionality, we split CV into Treatment Convenience (TCV) and General Convenience (GCV). Due to poor measurement precision, the GS IB was not pursued further. This resulted in 12 total IBs. In CAT simulations, an average of 3.7 and 7.3 items per IB were required to attain measurement at moderate and high precision, respectively.

Conclusions

Following rigorous psychometric assessment, we developed 12 valid glaucoma-specific QoL domains that can obtain highly precise person measure estimates using a small number of items.

Translational Relevance

GlauCAT will enable researchers and clinicians to quickly and comprehensively assess the impact of glaucoma and its associated interventions across a range of QoL domains.

Advances and challenges in the nanoparticles-laden contact lenses for ocular drug delivery

The delivery of drugs that target ocular tissues is challenging due to the physiological barriers of the eye like tear dilution, nasolacrimal drainage, blinking, tear turnover rate and low residence time Drug-laden contact lenses can be a possible solution to overcome some of these challenges. Nanoparticles are being extensively studied as novel systems for loading drugs into therapeutic contact lenses. The versatile features of the organic and inorganic nanoparticles and their diverse physicochemical properties make it possible to load and sustain drug release from the contact lenses. Nevertheless, several issues remains to be solved before its clinical application and commercialization such as changes in contact lens swelling (water content), transmittance, protein adherence, surface roughness, tensile strength, ion and oxygen permeability and drug leaching during contact lens manufacture. However, clinical studies demonstrated the potential of therapeutic contact lenses to manage the scientific, commercial and regulatory challenges to make its place in the market. This review highlights the different methodologies used to fabricate nanoparticle-laden contact lenses and highlights the major advances and challenges to commercialization.

siRNA Therapeutics in Ocular Diseases

The field of RNAi therapeutics has quickly adapted to the treatment of ocular diseases. Although the eye provides a unique system for the delivery of siRNAs, its complex structure and composition fostered the development of novel strategies for efficient gene silencing in the target compartment. Moreover, anterior and posterior segments differ in their multiple drug barriers and clearance mechanisms. This chapter summarizes the recent achievements in terms of routes of administration, chemical modifications, and delivery systems for siRNAs that specifically apply to eye disorders. Methods employed for siRNA detection/quantitation in ocular tissues are also described, together with safety concerns that need to be addressed to fulfill regulatory requirements of new drug approval. Even though RNAi therapies for ocular diseases have not yet translated into patient care, we document herein the rising number of candidate drugs currently under preclinical or clinical development.

Prophylactic effect of brinzolamide-brimonidine fixed combination on intraocular pressure spikes after intravitreal anti-VEGF injections

PURPOSE

To evaluate the effect of topical prophylaxis with brinzolamide-brimonidine fixed combination on short-term intraocular pressure (IOP) elevation after intravitreal injections of anti-vascular endothelial growth factors (anti-VEGF).

METHODS

This prospective comparative study included 56 eyes of 47 patients treated with intravitreal injections of anti-VEGF, and they were randomly divided into two groups. In control group (25 eyes), no prophylactic medication was used, whereas in case group (31 eyes) one drop of a fixed combination of brinzolamide-brimonidine was instilled two hours before the injection. IOP was measured before the injection and at 1 min, 10 min and 30 min post-injection in all eyes.

RESULTS

The mean IOP before injection at 1 min, 10 min and 30 min post-injection was 16,6 ± 2,8 mmHg, 53,4 ± 12 mmHg, 26,4 ± 5,5 mmHg and 17,9 ± 4 mmHg, respectively, in control group and 15,1 ± 3,4 mmHg, 42,6 ± 8,4 mmHg, 21,4 ± 5,5 mmHg and 12,4 ± 3,5 mmHg, respectively, in case group. At 1 min, 10 min and 30 min post-injection, the mean IOP was significantly lower in case group compared with control group (p < 0,001, p = 0,0014 and p < 0,0001, respectively), but no difference at the pre-injection IOP between the two groups was found (p = 0,09).

CONCLUSIONS

The prophylactic administration of one drop of brinzolamide-brimonidine fixed combination significantly reduces the IOP spikes during the first 30 min after the intravitreal anti-VEGF injection.

Selective laser trabeculoplasty versus topical medication as initial glaucoma treatment: the glaucoma initial treatment study randomised clinical trial

BACKGROUND/AIMS

To determine if selective laser trabeculoplasty (SLT) is superior to topical medication as a first-line treatment for glaucoma on quality of life (QoL) and clinical outcomes.

METHODS

In this international, longitudinal, multisite randomised controlled trial, treatment naïve mild-to-moderate primary open angle or exfoliation glaucoma patients were randomised 1:1 to SLT or topical medication. Glaucoma-specific QoL (primary outcome) was measured using the Glaucoma Outcomes Assessment Tool (GOAT; 342 items, 12 domains). Secondary outcomes included rate of successful intraocular pressure (IOP) reduction (>25% reduction from baseline) and presence of ocular surface disease including conjunctival hyperaemia and eyelid erythema. Our intention-to-treat analysis was performed at months 12 and 24.

RESULTS

Of 167 enrolled patients, 83 and 84 were randomised to SLT and topical medication, respectively; and 145 (n=75 SLT, n=70 medication) completed 24-month follow-up. While both treatment arms achieved significant within-group gains in GOAT outcomes at both endpoints, SLT patients reported a greater between-group improvement in 'social well-being' compared with medication patients (mean±SE=0.28±0.13; p=0.034) at 24 months. At month 24, the rate of successful IOP reduction was 18.6% (95% CI 3.0% to 34.3%, p=0.022) higher (absolute difference) in the medication compared with SLT group. More individuals in the medication group had conjunctival hyperaemia and eyelid erythema compared with SLT at 24 months.

CONCLUSION

Overall, we did not find evidence that SLT was superior to medication in improving glaucoma-specific QoL. While we found superior IOP reduction in the medication arm, eyelid erythema and conjunctival hyperaemia were more prevalent in these patients compared with the SLT group.

TRIAL REGISTRATION

ACTRN12611000720910.

Pulmonary safety of ophthalmic beta-blockers: a nationwide registry-based cohort study

PURPOSE

Ophthalmic beta-blockers, used in the treatment of increased intraocular pressure, are known to cause pulmonary adverse effects. Few, if any, studies have quantified the extent of the problem in a real-life population. In this nationwide study, we assess the pulmonary safety of patients initiating treatment with ophthalmic beta-blockers.

METHODS

Using the Danish Nationwide Registries from 1995 to 2012, we identified all individuals aged 20-90 years who initiated monotherapy with an intraocular pressure-lowering drug, with or without concomitant obstructive pulmonary disease. Risks of (i) switching to another drug and (ii) new onset of obstructive pulmonary disease during a 90-day follow-up were examined by cumulative risk and logistic regression models adjusted for available covariates.

RESULTS

The cohort consisted of 97 463 individuals. Odds ratios for drug switch in individuals without concomitant obstructive pulmonary disease (n = 86 568) were as follows: 1.47 for beta-blockers (95% confidence interval (CI): 1.35-1.61; p < 0.001), 2.68 for parasympathomimetics (95% CI: 2.32-3.10; p < 0.001) and 4.80 for alfa-2-agonists (95% CI: 4.17-5.53; p < 0.001). Odds ratios in individuals with concomitant obstructive pulmonary disease (n = 10 895) were as follows: 2.61 for parasympathomimetics (95% CI: 1.83-3.72; p < 0.001), 2.96 for beta-blockers (95% CI: 2.31-3.78; p < 0.001) and 3.54 for alfa-2-agonists (95% CI: 2.56-4.88; p < 0.001). There was no significant association between treatment class and new onset of obstructive pulmonary disease (p = 0.30).

CONCLUSION

Ophthalmic beta-blockers were associated with an increased risk of drug switch. However, the absolute risk was very small. No increased risk of new onset of obstructive pulmonary disease was found. Our data suggest that more patients might be eligible for ophthalmic beta-blockers.

Effects of a Novel Selective EP2 Receptor Agonist, Omidenepag Isopropyl, on Aqueous Humor Dynamics in Laser-Induced Ocular Hypertensive Monkeys

PURPOSE

To investigate the mechanism of the intraocular pressure (IOP)-lowering effect of a novel selective prostaglandin E2 receptor 2 (EP2) receptor agonist, omidenepag isopropyl (OMDI).

METHODS

The effect of OMDI on IOP and aqueous humor dynamics was evaluated in cynomolgus monkeys with unilateral laser-induced ocular hypertension. In a crossover manner, the hypertensive eye of each monkey was dosed once daily with 20 μL of either 0.002% OMDI or vehicle. On day 7 of dosing, IOP was measured by pneumatonometry, aqueous humor flow and outflow facility were evaluated by fluorophotometry, and uveoscleral outflow was calculated mathematically. Treatments were compared by paired t-tests.

RESULTS

OMDI at 0.002% significantly lowered IOP by 27%, 35%, and 44% at 0.5, 1.5, and 4 h after the last dosing, respectively. There was no difference in aqueous humor flow between vehicle and OMDI treatments. When comparing OMDI to the vehicle treatment, outflow facility and uveoscleral outflow were significantly (P < 0.05) increased by 71% and 176%, respectively.

CONCLUSIONS

OMDI, a novel IOP-lowering compound, reduced IOP by increasing outflow facility and uveoscleral outflow in nonhuman primates.

Considerations of prescribers and pharmacists for the use of non-selective β-blockers in asthma and COPD patients: An explorative study

RATIONALE, AIMS, AND OBJECTIVES

Despite recommendations in prevailing guidelines to avoid the use of non-selective (NS) β-blockers in patients with asthma or COPD, on average, 10 patients per community pharmacy receive NS β-blockers monthly. The aim of our study was to identify the reasons of prescribers and pharmacists to treat asthma and COPD patients with NS β-blockers.

METHODS

Fifty-three community pharmacists in the Netherlands selected patients with actual concurrent use of inhalation medication and NS β-blockers. For at least 5 patients, each pharmacist screened all medication surveillance signals and actions taken at first dispensing. Each pharmacist selected 3 different initial prescribers for a short interview to explore their awareness of the co-morbidity and reasons to apply NS β-blockers.

RESULTS

Pharmacists identified 827 asthma/COPD patients with actual use of NS β-blockers. From these, 153 NS β-blocker prescribers were selected and interviewed (64 general practitioners, 45 ophthalmologists, 24 cardiologists, and 20 other prescribers). One hundred seven prescribers were aware of the drug-disease interaction of the asthma or COPD co-morbidity when initiating the NS β-blocker, and 46 were not. From these, 40 prescribers did not consider the contraindication to be relevant. For 299 patients, medication surveillance signals and actions at first dispensing were retrieved. Patients used predominantly ocular timolol (39.8%), and the oral preparations propranolol (30.8%) and carvedilol (15.1%). In 154 cases, the pharmacy system generated a warning alert.

CONCLUSIONS

A substantial number of prescribers was unaware of the co-morbidity or did not regard NS β-blockers contraindicated, despite prevailing clinical guidelines. Improvement programs should target prescribers' awareness and knowledge of NS β-blockers in patients with asthma or COPD.

Impact of Combination Glaucoma Therapies on β-Blocker Exposure

PURPOSE

β-adrenergic receptor antagonists (β-blockers) used in the treatment of glaucoma are an often-overlooked source of systemic adverse events. Ophthalmic timolol has been associated with severe systemic adverse events including numerous cases resulting in death. In recent years the number of fixed-dose combination therapies for glaucoma has grown rapidly, and among available combination therapies only the nonselective β-blocker timolol is used as the β-blocker component.

METHODS

A population-based study was conducted in Ontario, Canada between January 1, 2001 and December 31, 2012 to assess the shift to combination therapies in the management of glaucoma, and to investigate the impact of this shift on the relative use of selective and nonselective β-blockers in patients with this disease.

RESULTS

Between 2001 and 2012 timolol (nonselective β-blocker) use grew at an average annual rate of 2.2% (P<0.0001), whereas betaxolol (selective β-blocker) use declined by 14.1% per year (P<0.0001). These changes in the relative use of betaxolol and timolol coincided with changes in the relative use of combination and single-drug therapies. Over the study period, the use of β-blockers as single-drug therapy decreased by 7.7% annually (P<0.0001). In contrast, the use of combination therapies containing a β-blocker increased by 7.6% annually (P<0.0001).

CONCLUSIONS

The introduction of fixed combination glaucoma therapies has been associated with a significant shift to greater use of nonselective β-blockers. In vulnerable older populations, this may have an important impact on patient safety that warrants further study.

Factors associated with excessive polypharmacy in older people

BACKGROUND

Older people are a growing population. They live longer, but often have multiple chronic diseases. As a consequence, they are taking many different kind of medicines, while their vulnerability to pharmaceutical products is increased. The objective of this study is to describe the medicine utilization pattern in people aged 65 years and older in Belgium, and to estimate the prevalence and the determinants of excessive polypharmacy.

METHODS

Data were used from the Belgian Health Interview Survey carried out in 2008. Each respondent was asked to show to the interviewer all medicines that he/she had taken in the 24 h prior to the interview. Excessive polypharmacy was defined as the use of nine different kind of medicines or more in the past 24 h; the relation with the Region of residence, age, gender and additional factors, such as socioeconomic status, living situation, health status and contacts with health services, was explored through multivariate models.

RESULTS

Eight percent of the older people (65 years or more) belong to the excessive polypharmacy group. Factors most strongly associated with excessive polypharmacy are: having a longstanding illness, chronic condition or handicap, at least 1 contact with a general practitioner in past 2 months and self-reported depression during the last year. Ninety percent of persons in the excessive polypharmacy group are taking medicines active on the cardiovascular system.

CONCLUSIONS

In order to optimize the use of medicines, it is necessary to find a balance between adequate treatment of diseases and avoiding adverse effects of medicines. Interventions should aim to increase awareness among healthcare professionals and patients; they should focus on general practitioners and patients with cardiovascular diseases, those suffering from depression and those aged 80 years and over. Monitoring excessive polypharmacy in the older population remains important. Further studies should explore more in depth other and more specific determinants of excessive polypharmacy.

Correlation between tea consumption and prevalence of hypertension among Singaporean Chinese residents aged ⩾40 years

By a cross-sectional epidemiology study, we attempted to correlate the consumption of tea and/or health supplements, living habits and socio-demographic factors to the prevalence of hypertension among Singaporean Chinese residents. Singaporean Chinese residents aged ⩾40 years were randomly selected and interviewed face-to-face by clinical research assistants. Hypertension was defined as measured systolic blood pressure at least 140 mm Hg and/or diastolic blood pressure at least 90  mmHg or self-reported history/treatment for hypertension. The prevalence of hypertension among the whole investigated population (N=1184, 58.27% females) was 49.73% and the prevalence increased to 66.47% in the sub-population aged ⩾60 years. High risk of hypertension was associated with age ⩾60 years (odds ratio (OR): 4.15-4.19, P<0.01), obesity (body mass index >25 kg m(-2), OR: 2.10-2.11, P<0.01), family history of hypertension (OR: 2.69-2.76, P<0.01), diabetes history (OR: 2.29-2.33, P<0.01), hyperlipidemia history (OR: 1.79-1.80, P<0.01), male (OR: 1.56-1.59, P<0.01) and coffee intake (OR: 1.44-1.46, P<0.05). In contrast, drinking green tea at least 150 ml per week was associated with lower hypertension risk (OR: 0.63, 95% confidence interval (CI): 0.43-0.91, P<0.05). Drinking combination of green tea and British tea was associated with higher reduction in the risk of hypertension (OR: 0.58, 95% CI: 0.39-0.85, P<0.05). This cross-sectional study suggests that consumption of tea, especially green tea and British tea, was associated with lowering the risk of hypertension. On the other hand, consumption of coffee could be a risk factor of hypertension. These findings may provide useful information for health promotion to reduce risk of hypertension and warrant further study to confirm and elucidate such association.

Phase I clinical trial of SYL040012, a small interfering RNA targeting β-adrenergic receptor 2, for lowering intraocular pressure

The objective of this study was to evaluate ocular tolerance, safety, and effect on intraocular pressure (IOP) of a topically administered small interfering RNA; SYL040012, on healthy volunteers. The study was an open-label, controlled, single-center study comprised of two intervals that enrolled 30 healthy subjects having IOP below 21 mmHg. SYL040012 was administered to one eye as a single dose to six subjects during interval 1. During interval 2 two different doses of SYL040012 were administered to one eye on a daily basis to two separate groups of 12 subjects each, over a period of 7 days. The contralateral eye was evaluated but not administered and served as control for the tolerance study. SYL040012 was well tolerated locally. No local or systemic adverse events related to the product developed in response to any of the doses studied. SYL040012 was not detected in plasma at any time point. Administration of SYL040012 over a period of 7 days reduced IOP values in 15 out of 24 healthy subjects regardless of the dose used. IOP decrease was statistically significant in response to one of the doses tested and responsiveness to SYL040012 seemed to be greater in individuals with higher baseline IOP.

In vitro and in vivo efficacy of SYL040012, a novel siRNA compound for treatment of glaucoma

Glaucoma is a progressive ocular syndrome characterized by degeneration of the optic nerve and irreversible visual field loss. Elevated intraocular pressure (IOP) is the main risk factor for glaucoma. Increased IOP is the result of an imbalance between synthesis and outflow of aqueous humor (AH). Blocking β2 adrenergic receptor (ADRB2) has shown to reduce IOP by decreasing production of AH at the ciliary body (CB). SYL040012 is a siRNA designed to specifically silence ADRB2 currently under development for glaucoma treatment. Here, we show that SYL040012 specifically reduces ADRB2 expression in cell cultures and eye tissues. The compound enters the eye shortly after administration in eye drops and is rapidly distributed among structures of the anterior segment of the eye. In addition, SYL040012 is actively taken up by cells of the CB but not by cells of systemic organs such as the lungs, where inhibition of ADRB2 could cause undesirable side effects. Moreover, SYL040012 reduces IOP in normotensive and hypertensive animal models and the effect appears to be long lasting and extremely well tolerated both locally and systemically.

Selective Laser Trabeculoplasty: A Clinical Review

Selective laser trabeculoplasty (SLT) is a safe and effective treatment modality for lowering the intraocular pressure in patients with glaucoma. It achieves its results by selective absorption of energy in the trabecular pigmented cells, sparing adjacent cells and tissues from thermal damage, with minimal morphological tissue alteration following treatment. On the basis of the peer-reviewed medical literature, SLT is efficacious in lowering IOP, as initial treatment or when medical therapy is insufficient in all types of open-angle glaucoma in all races. SLT achieves intraocular pressure reduction similar to that of argon laser trabeculoplasty but without the tissue destruction and side effects. Observed side effects following SLT were almost uniformly transient and minor. We review highlights of recently published studies on the mechanisms and clinical outcome of SLT in order to address frequently raised issues pertinent to SLT in the clinical practice.

KEY MESSAGES

Selective laser trabeculoplasty is a safe and effective treatment modality for lowering the intraocular pressure in patients with glaucoma. How to cite this article: Alon S. Selective Laser Trabeculoplasty: A Clinical Review. J Current Glau Prac 2013; 7(2):58-65.

Medical service encounters and payments associated with topical adjunctive therapy use of timolol for glaucoma

BACKGROUND

Topical β-blockers are commonly prescribed for primary open-angle glaucoma. Existing research is limited regarding respiratory or cardiovascular events that may result from using these topical β-blockers.

OBJECTIVE

To evaluate inpatient and outpatient service encounters and payments associated with the topical adjunctive use of the β-blocker timolol for glaucoma.

STUDY DESIGN

Retrospective data analysis using 2004-2011 IMS Lifelink Health Plan Claims Database.

PATIENTS

Beneficiaries were included if they had a diagnosis of glaucoma (International Classification of Diseases-Ninth Revision-Clinical Modification [ICD-9-CM] code 365.xx) and at least 4 years of continuous enrollment and glaucoma medication use (defined as at least one pharmacy claim each year). Beneficiaries who had 4 years of observation with no timolol use were categorized as "controls" and those with 2 years of non-timolol glaucoma medication use followed by consecutive years of adjunctive timolol use were considered "cases." Beneficiaries with 2 years of non-timolol glaucoma medication use followed by 1 year in which they used timolol adjunctively and then a year without timolol use were considered "discontinuers."

MAIN OUTCOME MEASURE

The rates of respiratory and cardiovascular disease in year 2 of the observation period were compared to the rates in year 3, and healthcare encounters and payments were also compared.

RESULTS

There were 24,271 glaucoma patients who did not receive timolol (controls), 1,406 beneficiaries who were prescribed timolol in addition to other glaucoma medications and continued its use (cases), and 299 beneficiaries who used adjunctive timolol for only a single year (discontinuers). More than half of each group was less than 65 years of age (58 % of controls, 53 % of cases, 54 % of discontinuers, p < 0.05). The rate of respiratory disease increased in all groups from year 2 to year 3 of the observation period, with increases of 1.0 %, 1.4 % and 5.0 % points among controls, cases and discontinuers, respectively (all between-group comparisons significant at p < 0.05). There were similar changes in the rate of cardiovascular disease, with increases of 1.3 %, 1.5 % and 4.7 % points among controls, cases and discontinuers, respectively (all between-group comparisons significant at p < 0.05). These increases were generally lower for younger beneficiaries and greater for those 65 years and older. Comparing years 2 and 3 of the observation period, discontinuers more than doubled their average rate of all-cause inpatient hospitalizations (0.35-0.83 encounters annually), while this rate remained steady for cases and controls (between-group comparisons significant at p < 0.05). There was little change in this rate among patients less than 65 years of age. Among those aged 65 years and older, there was a substantial increase for discontinuers, with a tripling of the average annual rate of inpatient hospitalizations from 0.45 to 1.48 (all between-group comparisons significant at p < 0.05). In this older group, both discontinuers and cases experienced more than a 20 % increase in outpatient service encounters compared to only 9 % for controls (all between-group comparisons significant at p < 0.05). Overall, discontinuers would be expected to have average annual medical payments US$3,600 greater than controls and US$3,200 greater than cases.

CONCLUSION

Adjunctive use of timolol by patients with glaucoma may be associated with increased respiratory and/or cardiovascular disease, hospitalizations and payments among patients for whom timolol may be contraindicated or who have yet undiagnosed manifestations of conditions for which it would be contraindicated.

Topical absorption and systemic toxicity

Dermal absorption of some chemicals and drugs can cause systemic toxicity. We evaluated several case reports from the past decade, which discuss the dermal absorption of a specific chemical and potential local and systemic effects. We focused on herbicide and pesticide exposure along with exposure to cutaneous medication, occupational contact, and cosmeceutical exposure. Although causality cannot be established in most cases, it is critical to be aware of the possible effects of topical absorption that may not be immediately apparent. We recommended further studies on specific chemicals to ascertain causality and determine the highest exposure level with no observed adverse affect level (NOAEL) and the reference dose (RfD). Post-marketing epidemiology data in most geographical areas are markedly limited. A weak link in public health resides in the inadequate reporting and workup of alleged chemically related adverse effects. This arena mandates a re-thinking of how to increase this reporting, and workup, as a backup to our preclinical and clinical studies. Public awareness and funding will be rewarded by increased evidence to backup pre-approval pre-marketing studies.

Brinzolamide/timolol: in open-angle glaucoma and ocular hypertension

Brinzolamide 1%/timolol 0.5% fixed combination (brinzolamide/timolol) is a twice-daily eyedrops suspension comprising the carbonic anhydrase-II inhibitor brinzolamide and the beta-adrenergic receptor antagonist timolol. Brinzolamide/timolol produced clinically relevant reductions in mean intraocular pressure (IOP) from baseline and was more effective than brinzolamide or timolol monotherapy in lowering IOP in a 6-month, randomized, phase III trial in patients with open-angle glaucoma or ocular hypertension (n = 523). The proportion of patients achieving a mean IOP of <18 mmHg was significantly greater in recipients of brinzolamide/timolol than in recipients of brinzolamide or timolol monotherapy. The IOP-lowering efficacy of brinzolamide/timolol was maintained for up to 12 months, and was no less effective than dorzolamide 2%/timolol 0.5% solution (dorzolamide/timolol) in a randomized, phase III, noninferiority trial (n = 437). Brinzolamide/timolol was generally well tolerated and was associated with significantly lower ocular discomfort scores than dorzolamide/timolol. Moreover, a significantly greater number of patients expressed a preference for brinzolamide/timolol over dorzolamide/timolol. The main ocular adverse event was blurred vision, and was not considered to be a safety issue.