Dorzolamide versus pilocarpine as adjunctive therapies to timolol: a comparison of patient preference and impact on daily life

In Vitro and In-Eye Comparison of Commercial Pilocarpine Ophthalmic Solution and an Optimized, Reformulated Pilocarpine for Presbyopia Treatment

INTRODUCTION

Pilocarpine hydrochloride (pilo) ophthalmic solution has traditionally been used for the treatment of glaucoma, with opportunities to improve the tolerability profile experienced by patients. Pilocarpine hydrochloride ophthalmic solution 1.25% (Vuity™, Allergan, an AbbVie company) was approved in late 2021 for the treatment of adults with presbyopia. This publication describes the properties of the optimized, proprietary vehicle of this new ophthalmic solution developed with the aim of improving tolerability upon instillation.

METHODS

An in vitro method determined the time required for the pH of pilo 1.25% in the proprietary vehicle (Optimized Formulation) and a commercially available 1% pilo ophthalmic solution (Generic Formulation) to equilibrate with the pH of simulated tear fluid (STF). In a pilot study, five of the six screened participants received one drop of the Optimized Formulation in one eye and Generic Formulation in the other. Ocular discomfort and vision blur were evaluated for each eye just prior to and at multiple times after drop instillation using visual analog scales (VAS), and adverse events were assessed.

RESULTS

The in vitro method showed that the Optimized Formulation achieved faster pH equilibration than the Generic Formulation. The pilot study revealed that the Optimized Formulation demonstrated less ocular discomfort, vision blur, and adverse events compared to the Generic.

CONCLUSION

The in vitro and pilot study of the Optimized Formulation indicated that it rapidly equilibrates to the physiologic pH of the tear film, providing greater comfort and tolerability while also minimizing vision blur. Overall, the proprietary vehicle is expected to improve comfort, result in less vision blur, and provide a well-tolerated alternative method to deliver pilo for the treatment of presbyopia when compared to what is commercially available.

Safety and Efficacy of AGN-190584 in Individuals With Presbyopia: The GEMINI 1 Phase 3 Randomized Clinical Trial

IMPORTANCE

AGN-190584 (Allergan, an AbbVie company) is an optimized topical formulation of pilocarpine hydrochloride, 1.25%, designed for managing presbyopia and enhanced with a proprietary vehicle.

OBJECTIVE

To evaluate the efficacy and safety of pilocarpine hydrochloride, 1.25%, in individuals with presbyopia.

DESIGN, SETTING, AND PARTICIPANTS

This vehicle-controlled, participant- and investigator-masked, randomized, phase 3 clinical study, GEMINI 1, enrolled individuals with presbyopia, aged 40 to 55 years, at 36 sites in the United States from December 21, 2018, to October 31, 2019. Analysis took place between February 2020 and December 2021.

INTERVENTIONS

AGN-190584 or the AGN-190584 formulation vehicle was administered bilaterally, once daily for 30 days.

MAIN OUTCOMES AND MEASURES

The proportion of participants with improvement of 3 or more lines in mesopic, high-contrast, binocular distance-corrected near visual acuity (DCNVA) at hours 3 and 6 on day 30 were the primary and key secondary efficacy end points, respectively. Safety measures included adverse events.

RESULTS

Of 323 participants who were randomized, 235 (72.8%) were female and 292 (90.4%) were White. The mean (SD) age was 49.6 (3.5) years, and the baseline mean (SD) mesopic DCNVA was 29.2 (6.3) letters. A total of 163 individuals were randomized to AGN-190584 and 160 were randomized to vehicle. GEMINI 1 met its primary and key secondary efficacy end points. On day 30, hour 3, the percentage of participants with improvement of 3 or more lines in mesopic DCNVA was 30.7% (50 of 163) in the AGN-190584 group and 8.1% (13 of 160) in the vehicle group (difference, 22.5% [95% CI, 14.3%-30.8%]; adjusted P < .001). At hour 6, those percentages were 18.4% (30 of 163) and 8.8% (14 of 160), respectively (difference, 9.7% [95% CI, 2.3%-17.0%]; adjusted P = .01). At hour 8, the between-group difference in 3 or more lines of mesopic DCNVA gains was not statistically significant, but clinically relevant prespecified outcome measures demonstrated AGN-190584 superiority to vehicle in least-squares mean (SE) mesopic DCNVA change from baseline at hour 8 (5.4 [0.51] vs 3.6 [0.52] letters; P = .009) and photopic distance-corrected intermediate visual acuity at hour 8 (3.9 [0.44] vs 2.4 [0.45] letters; P = .01) and hour 10 (3.5 [0.46] vs 1.7 [0.47] letters; P = .004). No participants with mesopic DCNVA improvement of 3 or more lines at hour 3 had losses of more than 5 letters in mesopic, high-contrast, binocular-corrected distance visual acuity. The onset of effect was at 15 minutes. AGN-190584 demonstrated an acceptable safety and tolerability profile.

CONCLUSIONS AND RELEVANCE

AGN-190584 demonstrated superiority over vehicle in mesopic DCNVA on day 30, hours 3 and 6, with an acceptable safety profile. AGN-190584 is a safe and efficacious topical therapy for presbyopia through 30 days.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03804268.

Combinations of Pilocarpine and Oxymetazoline for the Pharmacological Treatment of Presbyopia

Purpose

To determine the safety, efficacy, and tolerability of combinations of pilocarpine (Pilo) and oxymetazoline (Oxy) ocular drops dosed once daily and identify the optimal concentration of each for the pharmacologic treatment of presbyopia.

Design

Two concurrent Phase 2, multicenter, double-masked, randomized, vehicle-controlled studies, 1 short-term and 1 extended study.

Participants

Emmetropic individuals affected by presbyopia and in good general health.

Methods

Uncorrected near visual acuity (UNVA) was measured throughout both studies with various concentrations and combinations of Pilo (0%, 0.5% 1.0%, and 1.5%) and Oxy (0%, 0.0125%, 0.05%, and 0.125%). For safety, uncorrected distance visual acuity (UDVA) was measured, treatment-emergent adverse events (TEAEs) were recorded, and a temporal/supraorbital headache assessment was completed.

Main Outcome Measures

The primary efficacy end point was mean change from baseline in UNVA.

Results

In the short-term study, Pilo was shown to produce a significant dose response in the average increase of letters (P < 0.001), whereas Oxy did not have a significant impact (P = 0.4797). The addition or increase in concentration of Oxy did not reduce incidence or severity of headaches when compared with Pilo alone. Efficacy results from the extended study supported the results from the short-term study. As early as 15 minutes postadministration, a dose response could be seen, with peak effect at 1 hour. Peak improvement increased from day 1 to day 14 and was maintained up to day 28. The most common TEAE was headache. There was no clinically significant reduction in UDVA. A polynomial regression model was developed and determined that the optimal concentration range of Pilo is between 1.16% and 1.32%.

Conclusions

On the basis of the results of the 2 Phase 2 studies, AGN-190584, a reading drop containing an optimized concentration of pilocarpine HCl (1.25%) delivered using a proprietary formulation, was developed and is currently under investigation in Phase 3 studies.

Aiding Adherence to Glaucoma Medications: A Systematic Review

PURPOSE

To provide a comprehensive assessment of the strategies studied to date that focus on improving glaucoma medication adherence.

METHODS

A systematic review of the literature was conducted in MEDLINE (PubMed), Embase (Elsevier), and Scopus (Elsevier) from inception to March 1, 2021, of publications describing a device or strategy used to improve glaucoma medication adherence.

RESULTS

42 studies described by 50 papers were included. Five categories were identified: reminder systems, medication simplifications, behavioral change programs, education, and alternative engagement strategies.

CONCLUSION

Most studies (40 of the 42) addressed the question of improved adherence directly, with 26 finding improved adherence. Notably, 14 examined the clinical effects of the intervention, either in terms of intraocular pressure (IOP) or visual fields. Only three found an improvement in IOP. None demonstrated a between group difference in visual field progression.

A novel EyePhone© App for improving adherence to glaucoma therapy

PURPOSE

Despite advances in glaucoma treatment options, patient adherence and compliance remain very low. The EyePhone© App is a free non-commercial reminder application designed specifically for the needs of glaucoma patients. In this study, we evaluated its usefulness in improving adherence to medical treatment among glaucoma patients.

METHODS

This is a prospective multicenter interventional study. Glaucoma patients were recruited from a tertiary center and a large community glaucoma service center. After a short explanation, the EyePhone© App was installed on their smartphone device, and the notifications for the current medical treatment were entered. After enrollment and at 1-month follow-up, subjects completed the Morisky Medication Adherence Scale (MMAS-8) and the Quality of Life and Glaucoma 17-item (GlauQOL-17) questionnaires for evaluation of adherence and QOL, respectively.

RESULTS

In the study, 133 patients (71 men and 62 women) aged 62±15.5 years and using 2.0±0.9 IOP-lowering drugs participated. The proportion of highly adherent subjects improved from 29.3% (39/133) at baseline to 42.1% (56/133) at follow-up (P < 0.001), and the proportion of poorly adherent subjects decreased from 29.3 (39/133) to 20.3% (27/133) at follow-up (P = 0.012). QOL also improved, as evidenced by a significant increase in the GlauQOL-17 score (P < 0.05). In a subgroup of patients for whom IOP measurements were available, IOP reduced by 0.92 mmHg (P = 0.069).

CONCLUSIONS

Significant improvements in glaucoma adherence and QOL were achieved among poorly adherent glaucoma patients after 1 month of using the EyePhone© App.

Attributes Associated with Adherence to Glaucoma Medical Therapy and its Effects on Glaucoma Outcomes: An Evidence-Based Review and Potential Strategies to Improve Adherence

The treatment paradigm in glaucoma classically starts with exhausting all medical therapy prior to proceeding with laser or incisional surgery, although laser-first and surgery-first strategies have been explored in randomized clinical trials. Although glaucoma drops are proven to work well to lower intraocular pressure, slow the conversion from ocular hypertension, and slow the progression of disease in early open angle glaucoma, adherence to treatment is likely optimum in the randomized clinical trials that support these claims. In real-world scenarios, medical therapy often fails and practitioners are forced to proceed with more invasive treatment modalities to slow the progression of this blinding disease. This review aims to take an evidence-based approach to study the risk factors for poor adherence in glaucoma patients, to determine whether poor adherence is, in fact, associated with worse outcomes, and to seek potential strategies to improve adherence in these patients.

Interventions for improving adherence to ocular hypotensive therapy

BACKGROUND

Poor adherence to therapy is a significant healthcare issue, particularly in patients with chronic disease such as open-angle glaucoma. Treatment failure may necessitate unwarranted changes of medications, increased healthcare expenditure and risk to the patient if surgical intervention is required. Simplifying eye drop regimes, providing adequate information, teaching drop instillation technique and ongoing support according to the patient need may have a positive effect on improving adherence.

OBJECTIVES

To summarise the effects of interventions for improving adherence to ocular hypotensive therapy in people with ocular hypertension (OHT) or glaucoma.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 6), MEDLINE (June 1946 to June 2012), EMBASE (June 1980 to June 2012), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (June 1937 to June 2012), PsycINFO (1806 to June 2012), PsycEXTRA (1908 to June 2012), Web of Science (1970 to June 2012), ZETOC (1993 to June 2012), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 26 June 2012. We did not search the National Research Register (NNR) as this resource has now been now archived. We contacted pharmaceutical manufacturers to request unpublished data and searched conference proceedings for the Association for Research in Vision and Ophthalmology (ARVO), and the Annual Congress for the Royal College of Ophthalmologists (RCO).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared interventions to improve adherence to ocular hypotensive therapy for patients with OHT or glaucoma.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed the search results for eligibility and extracted data for included trials onto specifically designed forms. We did not pool data due to clinical and methodological heterogeneity.

MAIN RESULTS

Sixteen trials (1565 participants) met the inclusion criteria. Seven studies investigated some form of patient education. In six of these studies this education was combined with other behavioural change interventions including tailoring daily routines to promote adherence to eye drops. Eight studies compared different drug regimens (one of these trials also compared open and masked monitoring) and one study investigated a reminder device. The studies were of variable quality and some were at considerable risk of bias; in general, the length of follow-up was short at less than six months with only two studies following up to 12 months. Different interventions and outcomes were reported and so it was not possible to produce an overall estimate of effect. There was some evidence from three studies that education combined with personalised interventions, that is, more complex interventions, improved adherence to ocular hypotensive therapy. There was less information on other outcomes such as persistence and intraocular pressure, and no information on visual field defects, quality of life and cost. There was weak evidence as to whether people on simpler drug regimens were more likely to adhere and persist with their ocular hypotensive therapy. A particular problem was the interpretation of cross-over studies, which in general were not reported correctly. One study investigated a reminder device and monitoring but the study was small and inconclusive.

AUTHORS' CONCLUSIONS

Although complex interventions consisting of patient education combined with personalised behavioural change interventions, including tailoring daily routines to promote adherence to eye drops, may improve adherence to glaucoma medication, overall there is insufficient evidence to recommend a particular intervention. The interventions varied between studies and none of the included studies reported on the cost of the intervention. Simplified drug regimens also could be of benefit but again the current published studies do not provide conclusive evidence. Future studies should follow up for at least one year, and could benefit from standardised outcomes.

Patient satisfaction with topical ocular hypotensives

BACKGROUND

The aim of this study is to assess patient satisfaction, convenience of use, ease of administration, side effects and treatment burden of topical ocular hypotensives.

DESIGN

Prospective, observational cohort.

PARTICIPANTS

Two thousand five hundred and forty-one patients with glaucoma or ocular hypertension.

METHODS

The Treatment Impact Patient Satisfaction Scale (TIPSS) was administered by mail to all patients with glaucoma or ocular hypertension registered with Glaucoma New Zealand during a 3-month study period. The questionnaire assessed patient demographics; topical ocular hypotensive use including number of medications, frequency of administration, ease of use, class of medication, and presence/severity of side effects; impact on quality of life; and patient satisfaction. Univariate and multivariate analyses were performed to identify determinants of patient satisfaction.

MAIN OUTCOME MEASURES

Patient satisfaction.

RESULTS

Almost 80% of respondents were either 'very satisfied' or 'satisfied' with topical ocular hypotensives. Factors that were predictive of patient satisfaction included satisfaction with frequency of eye drop use {odds ratio (OR) 2.4 (95% confidence interval [CI] 1.8-3.1); P < 0.001}, subjective convenience (OR 2.6 [95% CI 2.0-3.4]; P < 0.001) and ease of administration (OR 2.5 [95% CI 2.0-3.3]; P < 0.001). Male gender was associated with lower satisfaction (OR 0.6 [95% CI 0.5-0.9]; P = 0.01). Factors that were not predictive of patient satisfaction included age, duration of eye drop use, class of medication and the presence of side effects.

CONCLUSIONS

Patients with glaucoma and ocular hypotension are satisfied with topical ocular hypotensives. Efforts to improve patient satisfaction should focus on convenience and ease of administration.

A comparison of the long-term effects of dorzolamide 2% and brinzolamide 1%, each added to timolol 0.5%, on retrobulbar hemodynamics and intraocular pressure in open-angle glaucoma patients

PURPOSE

To compare the effect on the retrobulbar hemodynamics and intraocular pressure (IOP) of dorzolamide 2% and brinzolamide 1%, each added to timolol 0.5% in patients with primary open-angle glaucoma (POAG).

METHODS

146 POAG patients were prospectively randomized to receive either dorzolamide 2% or brinzolamide 1% BID, each added to timolol 0.5%, during a 60-month evaluator-masked study. At baseline and every 6 months for 60 months, we measured the retrobulbar hemodynamic parameters in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCA) using color Doppler imaging (CDI), intraocular pressure (IOP), and blood pressure measurements.

RESULTS

Dorzolamide significantly increased the end-diastolic velocity (EDV) in the OA in 1.22 cm/s, 95% confidence interval (95% CI) 0.90-1.56 cm/s, P < 0.001 and reduced the resistivity index (RI) in the OA in 0.04 units, 95% CI 0.03-0.05, P < 0.001. None of the retrobulbar parameters changed significantly on therapy with brinzolamide when the results were analyzed at month 60. Both dorzolamide and brinzolamide significantly decreased IOP (-4.3, 95% CI -4.5 to -4.2 mmHg and -4.3, 95% CI -4.4 to -4.2 mmHg, respectively). Dorzolamide significantly reduced the RI in the OA from 0.74 (0.02) to 0.70 (0.02), CRA from 0.66 (0.02) to 0.62 (0.02), and SPCA from 0.66 (0.02) to 0.62 (0.02), P < 0.001, respectively.

CONCLUSIONS

Our results suggest augmented retrobulbar blood flow after 5 years of treatment with dorzolamide but not with brinzolamide, each added to timolol, in POAG patients.

Interventions for improving adherence to ocular hypotensive therapy

BACKGROUND

Poor adherence to therapy is a significant healthcare issue, particularly in patients with chronic disease such as open angle glaucoma. Treatment failure may necessitate unwarranted changes of medications, increased healthcare expenditure and risk to the patient if surgical intervention is required. Simplifying eye drop regimes, providing adequate information and ongoing support according to patient need, may have a positive effect on improving adherence.

OBJECTIVES

To summarise the effects of interventions for improving adherence to ocular hypotensive therapy in people with ocular hypertension (OHT) or glaucoma.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, ZETOC and OpenSIGLE. In addition, we searched research registers of ongoing studies. We contacted pharmaceutical manufacturers to request unpublished data and searched conference proceedings for the Association for Research in Vision and Ophthalmology (ARVO), and the Annual Congress for the Royal College of Ophthalmologists (RCO). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 15 January 2009.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi RCTs that compared interventions to improve adherence to ocular hypotensive therapy for patients with OHT or glaucoma.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed the search results for eligibility and extracted data for included trials onto specifically designed forms. We calculated the mean difference for continuous data and relative risks for dichotomous data. Where appropriate, we pooled data using a fixed-effect model.

MAIN RESULTS

Eight trials met the inclusion criteria. There was considerable heterogeneity of interventions and reported outcome measures and therefore, meta-analysis was limited to two studies. Overall, studies were not of high quality due to small sample sizes, missing data and short term follow-up. Three of five drug comparison studies provided evidence that reducing the frequency of drops can improve adherence. However, the study that compared the least frequent regime with one of the most complicated, showed no difference in reported adherence. A small study of thirteen patients found a reminder device beneficial to adherence levels yet only one of two studies involving education and individualised care planning was found to be successful.

AUTHORS' CONCLUSIONS

Interventions involving simplified dosing regimes, reminder devices, education and individualised care planning, did show improvements in adherence rates. However, due to inadequate methodological quality and heterogeneity of study design we are unable to advocate any particular interventions at this time.

Efeitos maleato de timolol 0.5% do cloridrato de dorzolamida 2%, e da associação de ambas na pressão intra-ocular

Avaliaram-se efeitos da dorzolamida do timolol e da combinação de ambos sobre pressão intra-ocular (PIO) de cães normais, além de alterações no olho contralateral, não-tratado. Foram utilizados 60 cães sadios, distribuídos em três grupos (G) de 20 animais. No primeiro grupo (GT), foi avaliada a ação do maleato de timolol 0,5% na PIO; no segundo (GD), a ação do cloridrato de dorzolamida 2%; e, no terceiro (GTD), o efeito da associação fixa timolol/dorzolamida. A PIO foi aferida utilizando-se tonômetro de aplanação (Tonopen®), uma hora antes e uma, duas, quatro, seis e oito horas após a instilação do colírio em análise no olho esquerdo. O efeito da associação timolol/dorzolamida foi mais intenso (27%) que os efeitos do timolol (21,9%) e da dorzolamida (22,4%) na redução da PIO. No olho contralateral, verificou-se redução de 7% no GT, 13,8% no GD e 13,6% no GTD, após quatro e duas horas da administração.

The clinical validity of the treatment satisfaction survey for intraocular pressure in ocular hypertensive and glaucoma patients

PURPOSE

To provide initial validation of the Treatment Satisfaction Survey-Intraocular Pressure (TSS-IOP) quality-of-life survey that analyses specific issues related to side effects, patient satisfaction, and compliance.

METHODS

A prospective, observational cohort of 250 consecutive patients with primary open-angle glaucoma or ocular hypertension was administered the TSS-IOP survey.

RESULTS

Factors that correlated with patient satisfaction included perceived effectiveness of the medicine (F=7.47, P<0.001), ocular irritation (F=6.06, P<0.001), conjunctival hyperaemia (F=4.40, P<0.001), ease of use (F=8.52, P<0.001), and convenience of use (F=6.90, P<0.001). Patient compliance, acceptance of their illness, and knowledge of glaucoma were also related to perceived effectiveness of the medicine (P<0.001), ease of use (P<0.05) and convenience (P<0.001). Physician ratings of patient pressure control, side effects, and instillation problems also were significantly correlated to patient satisfaction (R=0.13-0.26, P=0.05-0.001). The physician ratings of patient compliance, however, were not significantly related to any dimension of patient satisfaction (P>0.05). Among monotherapy prostaglandin treatments, latanoprost demonstrated statistically greater satisfaction than bimatoprost or travoprost regarding conjunctival hyperaemia (P<0.05) and eye irritation (P<0.01).

CONCLUSIONS

This study provides initial evidence that patient satisfaction may be related to compliance, perceived effectiveness of treatment, adverse side effects, ease and convenience of use, acceptance of illness, and knowledge of glaucoma.

New glaucoma medications in the geriatric population: efficacy and safety

Glaucoma can be considered a disease of the aging eye. Most medications used to treat glaucoma are in topical eyedrop form and may cause numerous untoward systemic effects in older persons. In recent years, several new ocular hypotensive medications have become available. These medications are being used more commonly because there is a growing trend by ophthalmologists to aggressively lower intraocular pressure. Therefore, geriatricians require a comprehensive knowledge of medications used to treat glaucoma, in addition to an understanding of their mechanism of action profiles of untoward effects and possible interactions with other diseases or medications. Therefore, we performed a review of the medications recently introduced into clinical practice. We selected drugs approved by the U.S. Food and Drug Administration between 1996 and September 2001. The safety profiles of these agents and their untoward side effects were reviewed by class: topical carbonic anhydrase inhibitors (brinzolamide: ocular tolerance, taste perversion), beta-adrenoceptor antagonists (timolol: bradycardia and bronchospasm), alpha-adrenergic agonists (brimonidine: oral dryness, headache, and fatigue), and prostaglandin analogs (latanoprost, bimatoprost, travoprost, and unoprostone isopropyl: ocular hyperemia, iris color changes). The function of this review is to make geriatricians more aware of the efficacy and untoward effects of medications recently introduced into clinical practice. We recommend that geriatricians perform a medication review on all medications their patients use, including eye drops.

Topical dorzolamide 2%/timolol 0.5%: a review of its use in the treatment of open-angle glaucoma

The nonselective beta-blocker timolol and the carbonic anhydrase inhibitor dorzolamide both lower intraocular pressure (IOP). Timolol and dorzolamide have different mechanisms of action and their effects are additive when administered together. Therefore, the 2 drugs are frequently used concomitantly to treat patients with open-angle glaucoma who have not adequately responded to first-line therapy. A barrier to good compliance with concomitant therapy is the need to administer 5 or 6 drops of medication on 2 or 4 occasions during the day. Timolol 0.5% and dorzolamide 2.0% have therefore been combined in a single formulation, reducing the number of administrations required to 2 per day. Clinical trials in patients with glaucoma have demonstrated that dorzolamide 2%/timolol 0.5% (dorzolamide/timolol) is superior to monotherapy with the individual components. When dorzolamide/timolol administered twice daily was compared with concomitant treatment with dorzolamide 2% and timolol 0.5%, each administered twice daily for 90 days, both regimens resulted in marked lowering of trough IOP (measured just before the morning dose) compared with baseline (reduction in IOP = 4.2mm Hg). The effect of the 2 regimens on IOP at all time points, both before treatment and at peak effect (2 hours after treatment), were virtually indistinguishable. When the combined formulation was compared with a concomitant regimen that included dorzolamide 2% 3 times daily and timolol 0.5% twice daily the concomitant regimen was slightly more efficacious than the combined regimen at trough after 90 days: IOP was lowered by 3.6mm Hg in the combined group versus 4.1 mm Hg in the concomitant group. Dorzolamide/timolol has been compared with concomitant administration of timolol 0.5% and the IOP lowering miotic drug, pilocarpine 2.0%. This non-blind patient-preference study found that both regimens reduced IOP. However, the dorzolamide/timolol combination was preferred by the patients because of reduced frequency and severity of adverse effects and less frequent administration. Dorzolamide/timolol was well tolerated in clinical trials, the adverse effects reflected those of the individual components, and no additional tolerability issues were identified. However, the potential for timolol to cause cardiorespiratory effects must be considered when prescribing this combination. Furthermore, dorzolamide is a sulfonamide and can cause allergic reactions in those who are hypersensitive to this class of drug.

CONCLUSIONS

Dorzolamide/timolol is a well tolerated and effective fixed combination for lowering IOP in the treatment of open-angle glaucoma and is likely to be useful in those patients who do not respond adequately to first-line monotherapy. Compared with concomitant therapy with the same 2 drugs the primary advantage is convenience, which may lead to improved compliance. Studies of compliance and comparisons with other currently available combination therapies would be useful to fully define the value of the formulation. Nonetheless, dorzolamide combined with timolol in a single applicator system will be a useful addition to the treatment options for glaucoma, a leading cause of preventable blindness.

Pharmacological and ocular hypotensive properties of topical carbonic anhydrase inhibitors

There was a time gap of over 40 years between the demonstrated oral effectiveness of acetazolamide in lowering the intraocular pressure (IOP) of glaucoma patients and the introduction of a topical carbonic anhydrase (CA) inhibitor. This is due to the fact that CA-II, the isoenzyme which most likely plays an important role in the production of aqueous humor in humans, must be essentially inhibited by 100% to elicit a pharmacological response. The lack of success with earlier attempts to obtain a topical agent stems from an inability to attain and maintain a sufficiently high intraocular concentration of drug to achieve the required inhibition of CA. Dorzolamide and brinzolamide are two topical CA inhibitors which are currently available to treat ocular hypertension and/or glaucoma. Dorzolamide is a very potent inhibitor of CA-II and its site of action is local within the eye. Like oral CA inhibitors, topically applied dorzolamide lowers IOP by decreasing the production of aqueous humor. The drug is used in monotherapy as a 2% solution administered three times daily. Its ocular hypotensive effect is comparable to that of timolol at peak but is somewhat less at trough. The IOP lowering effect of timolol is enhanced by the twice daily administration of 2% dorzolamide either concomitantly or in combination. Topically applied dorzolamide is generally well tolerated and had a low drop-out rate in clinical studies. The most frequent ocular adverse experience is burning and/or stinging. Corneal and lenticular problems have generally not been encountered with long-term therapy with dorzolamide. Topically applied dorzolamide penetrates directly to the posterior segment of the eye and its presence is consistent with the initial report that dorzolamide increases retinal blood flow velocity in patients with normal tension glaucoma. The most frequent systemic adverse experience is a transient bitter taste. Biochemical changes indicative of the systemic inhibition of CA have not been observed in monotherapy studies lasting up to 2 years. This is in harmony with the inability of dorzolamide at steady-state to saturate CA in the red blood cell and the failure to detect its presence in plasma. A 1% suspension of brinzolamide is comparable to 2% dorzolamide in lowering IOP, both drugs being administered three times daily. Although brinzolamide has a lower incidence of burning/ stinging, it elicits more blurred vision.

Comparison of dorzolamide and pilocarpine as adjunctive therapy in patients with open-angle glaucoma and ocular hypertension

Many patients with glaucoma or ocular hypertension initially receive beta-blocker monotherapy to control intraocular pressure (IOP), but some of these patients will require an additional IOP-lowering agent within 1 year. This active-controlled, double-masked, randomized, multicenter, 12-week study compared the effectiveness and tolerability of dorzolamide hydrochloride ophthalmic solution 2% TID with those of pilocarpine hydrochloride 2% QID as adjunctive therapy to timolol maleate ophthalmic gel-forming solution (TG) 0.5% QD as measured by changes in IOP and occurrence of adverse events. One hundred ninety-four patients with open-angle glaucoma or ocular hypertension participated in this study. Their mean age was approximately 63 years. Slightly more than one half were white, and approximately one third were black. After a 3-week run-in period during which all patients received TG 0.5% QD, patients with an IOP of > or = 22 mm Hg at the morning trough measurement were randomly assigned to receive additional double-masked therapy with either dorzolamide or pilocarpine. The primary outcome measure was the mean change in IOP at the morning trough measurement from baseline to week 12. The secondary outcome measure was the mean change in IOP at the morning peak measurement from baseline to week 12. There was no significant difference in IOP-lowering effect between the 2 drugs at either morning trough or morning peak. The mean change in IOP at morning trough was -3.17 mm Hg (-12%) in patients receiving dorzolamide; it was -3.45 mm Hg (-13%) in patients receiving pilocarpine. The mean change in IOP at morning peak was -2.25 mm Hg (-10%) for patients who received dorzolamide and -2.51 mm Hg (-11%) for those who received pilocarpine. In the pilocarpine group, 62 (63%) patients experienced > or =1 adverse event compared with 35 (36%) patients in the dorzolamide group (P < 0.001). Twenty-one (21%) patients in the pilocarpine group discontinued treatment because of an adverse event compared with 2 (2%) patients in the dorzolamide group (P < 0.001). These results demonstrate that dorzolamide and pilocarpine were equally effective as adjunctive therapy in lowering IOP but that dorzolamide was better tolerated.

Comparison of the safety and efficacy of the fixed combination of dorzolamide/timolol and the concomitant administration of dorzolamide and timolol: a clinical equivalence study. International Clinical Equivalence Study Group

AIMS

To compare the tolerability and efficacy of a fixed combination solution of dorzolamide/timolol (Cosopt), administered twice daily with the concomitant administration of its components, dorzolamide (Trusopt) twice daily and timolol (Timoptic) twice daily.

METHODS

After a 2 week timolol run in, patients with open angle glaucoma or ocular hypertension were randomised (1:1) to receive treatment with either the dorzolamide/timolol combination solution twice daily (combination) or the dorzolamide solution twice daily plus timolol maleate solution twice daily (concomitant) for 3 months.

RESULTS

299 patients were entered and 290 patients completed the study. Compared with the timolol baseline, additional IOP lowering of 16% was observed at trough (hour 0) and 22% at peak (hour 2) at month 3 in both the concomitant and combination groups. The IOP lowering effects of the two treatment groups were clinically and statistically equivalent as demonstrated by the extremely small point differences (concomitant--combination) observed in this study--0.01 mm Hg at trough and 0.08 mm Hg at peak. The safety variables of the concomitant and combination groups were very similar. Both combination and concomitant therapy were well tolerated and few patients discontinued due to adverse effects.

CONCLUSIONS

The dorzolamide/timolol combination solution administered twice daily is equivalent in efficacy and has a similar safety profile to the concomitant administration of the components administered twice daily.

The efficacy and safety of the dorzolamide-timolol combination versus the concomitant administration of its components. Dorzolamide-Timolol Study Group

OBJECTIVE

To evaluate whether a fixed combination of 2% dorzolamide and 0.5% timolol given twice daily showed equivalent efficacy to the concomitant administration of 2% dorzolamide given three times daily and 0.5% timolol given twice daily in patients whose intraocular pressure (IOP) remained elevated during monotherapy with 0.5% timolol twice daily.

DESIGN

Multicenter, parallel, randomized, double-masked clinical trial with an open-label extension.

PARTICIPANTS AND INTERVENTION

In the masked phase, 242 patients received either the dorzolamide-timolol combination twice daily and placebo three times daily or dorzolamide three times daily and timolol twice daily for up to 3 months. In the open-label extension, 220 patients received the dorzolamide-timolol combination twice daily for up to 9 months.

MAIN OUTCOME MEASURES

The criterion for establishing treatment equivalency was a 95% or greater confidence that the absolute difference in the mean change in IOP from baseline was less than 1.5 mmHg between treatments.

RESULTS

During 3 months of treatment, the dorzolamide-timolol combination reduced IOP relative to the 0.5% timolol baseline by approximately 14% at hour 0 (just before the morning dose), 20% at hour 2, and 15% at hour 8. The IOP-lowering effect of concomitant therapy with dorzolamide and timolol was approximately 16% at hour 0.20% at hour 2, and 17% at hour 8. At hours 0, 2, and 8, there was greater than 97% confidence that the treatments were equivalent. During the open-label extension, the mean IOP reduction ranged from 14% to 15% at hour 0 and from 20% to 21% at hour 2. The treatment groups were generally comparable in terms of adverse events, symptoms, ocular signs, visual acuity, visual fields, physical examination, and laboratory measures.

CONCLUSIONS

The IOP-lowering effect of the dorzolamide-timolol combination is comparable to that of dorzolamide three times daily plus timolol twice daily and is maintained for up to 1 year. The dorzolamide-timolol combination provides clinically important reduction in IOP relative to baseline treatment with timolol alone and is generally well-tolerated for up to 1 year.

A randomized trial in patients inadequately controlled with timolol alone comparing the dorzolamide-timolol combination to monotherapy with timolol or dorzolamide. Dorzolamide-Timolol Combination Study Group

OBJECTIVE

To compare the dorzolamide-timolol fixed combination twice daily to its components, timolol maleate and dorzolamide hydrochloride, given in their usual monotherapy regimens in patients whose intraocular pressure (IOP) was not controlled on timolol twice daily alone.

DESIGN

Parallel, randomized, double-masked, and active-controlled study.

PARTICIPANTS

Enrolled were 253 patients from 22 sites throughout the United States.

INTERVENTION

After a 3-week run-in of timolol (TIMOPTIC; Merck & Co., Inc., Whitehouse Station, NJ) twice daily, eligible patients received either the combination (COSOPT; Merck & Co., Inc., Whitehouse Station, NJ) twice daily (plus placebo to ensure masking), timolol twice daily (plus placebo to ensure masking), or dorzolamide (TRUSOPT; Merck & Co. Inc., Whitehouse Station, NJ) three times daily for 3 months.

MAIN OUTCOME MEASURES

Intraocular pressure taken at hours 0 (trough) and 2 (peak) after week 2 and months 1, 2, and 3 was compared to baseline within each treatment group and between the combination and each component group. The safety profile of the combination was compared to each component.

RESULTS

The combination was numerically superior at all study timepoints and was statistically superior at all timepoints except for month 2, hour 0 for timolol, and month 2, hour 2 for dorzolamide. The safety profile of the combination reflected those of its two components. The number of patients reporting ocular or local adverse experiences was greater for the combination (45%) and dorzolamide (45%) than for timolol (27%), with burning and/or stinging eye being the most frequently reported.

CONCLUSION

The dorzolamide-timolol combination provides additional IOP lowering compared to either of its individual components and generally is well-tolerated.