Comparison of topical brinzolamide 1% and dorzolamide 2% eye drops given twice daily in addition to timolol 0.5% in patients with primary open-angle glaucoma or ocular hypertension

PURPOSE: The aim was to compare topical brinzolamide 1% twice daily with dorzolamide 2% twice daily, each given with timolol 0.5% twice daily, for safety and effects on intraocular pressure in patients with primary open-angle glaucoma or ocular hypertension. METHODS: This double-blind, randomized, active controlled, parallel group study was conducted multinationally at 31 sites, in 241 patients as above, with assessments at baseline and monthly during 3 months of treatment. The primary end point was a diurnal reduction of trough/peak intraocular pressure from a timolol 0.5% twice daily baseline. RESULTS: Both treatment regimens reduced intraocular pressure significantly at all time points (P <.001): brinzolamide plus timolol by -3.6 to -5.3 mm Hg (-14.2 to -21.9%), dorzolamide plus timolol by -3.6 mm Hg to -5.1 mm Hg (-14.1 to -21.2%). Clinically relevant intraocular pressure reductions (decreases 5 mm Hg or greater or absolute intraocular pressure values 21 mm Hg or less) were manifested by 50.0% to 89.3% of patients under brinzolamide plus timolol and by 43.9% to 85.4% under dorzolamide plus timolol. The treatments were equivalent in mean intraocular pressure-lowering. In general, both regimens were well tolerated. However, more patients (P =.001) experienced at least one adverse event with dorzolamide plus timolol (32.8%) as compared with brinzolamide plus timolol (14.7%); also, more patients (P =.001) experienced ocular discomfort (stinging and burning) after dorzolamide plus timolol (13.1%) than after brinzolamide plus timolol (1.7%). CONCLUSIONS: In terms of intraocular pressure reduction, brinzolamide 1% twice daily was equivalent to dorzolamide 2% twice daily, each added to timolol 0.5% twice daily, but brinzolamide produced significantly less ocular burning and stinging.     

A 3-month randomized controlled trial of bimatoprost (LUMIGAN) versus combined timolol and dorzolamide (Cosopt) in patients with glaucoma or ocular hypertension

PURPOSE: To compare the efficacy and safety of topical bimatoprost (LUMIGAN; Allergan, Inc., Irvine, CA) once daily with that of topical combined timolol and dorzolamide (Cosopt; Merck and Co, Inc., Whitehouse Station, NJ) twice daily. DESIGN: Prospective, randomized, double-masked, multicenter clinical trial. PARTICIPANTS: One hundred seventy-seven patients with a diagnosis of glaucoma or ocular hypertension and inadequate control of intraocular pressure (IOP) after at least 2 weeks of topical timolol maleate 0.5% monotherapy. METHODS: Patients were randomized to receive bimatoprost 0.03% once daily (n = 90) or combined timolol 0.5% and dorzolamide 2% twice daily (n = 87) over a 3-month period. MAIN OUTCOME MEASURES: Intraocular pressure, the primary end point, was measured at 8 AM and 10 AM at baseline, week 1, and months 1, 2, and 3, and also at 4 PM and 8 PM at baseline and month 3. RESULTS: Bimatoprost provided significantly greater IOP lowering compared with combined timolol and dorzolamide. At the 8 AM measurements, bimatoprost lowered mean IOP 6.8 mmHg to 7.6 mmHg from baseline, whereas combined timolol and dorzolamide lowered mean IOP 4.4 to 5.0 mmHg from baseline (P<0.001). At the last follow-up, patients had better diurnal IOP control with bimatoprost than combined timolol and dorzolamide. At 8 AM at the 3-month visit, the percentages of patients achieving IOPs of 相似文献   

Preclinical overview of brinzolamide

The development of topically active carbonic anhydrase inhibitors (CAIs) is a significant recent achievement in glaucoma medical treatment. Brinzolamide, the newest topical CAI, exhibits selectivity, high affinity, and potent inhibitory activity for the carbonic anhydrase type II isozyme (CA-II), which is involved in aqueous humor secretion. These characteristics, along with good ocular bioavailability, make brinzolamide maximally effective in lowering intraocular pressure (IOP) by locally inhibiting CA-II in the ciliary processes and suppressing aqueous humor secretion. Notable among its attributes as a safe and efficacious glaucoma drug is brinzolamide's superior ocular comfort profile because of its optimized suspension formulation at physiologic pH. The degree of tolerability in the eye is considered an important determinant of a patient's willingness to comply with the dosing regimen for a long-term glaucoma medication. Results from the preclinical pharmacologic evaluation of brinzolamide indicated that it acts specifically to inhibit CA without significant other pharmacologic actions that could introduce undesired side effects. Moreover, the typical side effects associated with systemically administered CAIs are expected to occur at a lower incidence or not occur at all with brinzolamide, as its therapeutic dose and low systemic absorption do not produce a problematic level of systemic CA inhibition. Brinzolamide's long tissue half-life in the eye, particularly in the iris-ciliary body, favors a prolonged duration of IOP lowering. This was substantiated in clinical trials, which showed that twice-daily brinzolamide provides as significant an IOP reduction as three-times-daily brinzolamide or dorzolamide in a relatively high percentage of patients. Brinzolamide has been shown by the laser Doppler flowmetry technique to improve blood flow to the optic nerve head in pigmented rabbits after topical administration, without producing an increase of blood pCO2, indicating a potential for a local vasodilatory effect involving the optic nerve head circulation. The mean concentration of brinzolamide found in the retina of pigmented rabbits (0.338 microg equivalents/g) after a single dose of 14C-brinzolamide is sufficient to inhibit CA-II. These data suggest that topical brinzolamide could improve the blood flow in the optic nerve head in humans should it inhibit carbonic anhydrase in that vascular bed. Brinzolamide is a new topically active CAI that is safe and efficacious for reducing intraocular pressure. It offers the convenience of topical dose administration and greater freedom from side effects related to the inhibition of CA seen with the systemic administration of CAIs. Its formulation has been optimized to provide greater comfort upon instillation, and this can result in a higher compliance rate by the patient. Results of studies in animals show that brinzolamide has promise for increasing blood flow to the optic nerve head; however, this requires further assessment in the clinic. Brinzolamide represents a significant technical achievement and an important addition to the medical treatment of glaucoma as both a primary and an adjunctive drug.     

Intraocular pressure-lowering effects of commonly used fixed combination drugs with timolol in the management of primary open angle glaucoma

AIM:To evaluate intraocular pressure (IOP)-lowering effect and ocular tolerability of brimonidine/timolol, dorzolamide/timolol and latanoprost/timolol fixed combination therapies in the management of primary open angle glaucoma.METHODS:Each drug was administered for two months, after which a circadian tonometric curve was recorded using a Goldmann applanation tonometer. Ocular discomfort (conjunctival hyperemia, burning or stinging, foreign body sensation, itching, ocular pain) of each eye was assessed by the subject on a standardized ocular discomfort scale.RESULTS:Among the three study groups, there were no significant differences in the mean baseline IOP measurements, mean 2^nd mo IOP measurements, and mean (%) change of IOPs from baseline. Among the three study groups, there were no significant differences in the mean IOP measurements obtained at circadian tonometric curves at baseline and at two months controls. In sum brimonidine/timolol, dorzolamide/timolol and latanoprost/timolol fixed combination therapies showed similar effects on IOP levels.CONCLUSION:Brimonidine/timolol, dorzolamide/timolol and latanoprost/timolol fixed combination therapies showed similar lowering efficaties on IOP levels whereas there was no any difference between each other.     

The efficacy and ocular discomfort of substituting brinzolamide for dorzolamide in combination therapy with latanoprost, timolol, and dorzolamide.

PURPOSE: The aim of this study was evaluate the efficacy and ocular discomfort of substituting brinzolamide for dorzolamide in patients with glaucoma treated by latanoprost, timolol, and dorzolamide. METHODS: An 8-week, prospective, randomized, open-label, comparative study was performed in 58 patients with primary open-angle glaucoma treated by latanoprost, timolol, and dorzolamide. These patients were randomly enrolled into two groups: (1) dorzolamide three times daily was substituted with brinzolamide twice-daily (substituting group); and (2) dorzolamide three times daily was continued (control group). Intraocular pressure (IOP) was measured at baseline, 4, and 8 weeks after the enrollment. Subjective ocular discomfort (irritation and blurred vision) at the time of the instillation of the patient was noted with interview. RESULTS: The IOPs at baseline, 4 and 8 weeks after the enrollment were 17.7 +/- 2.7 mmHg, 17.5 +/- 2.6 mmHg, and 17.4 +/- 2.9 mmHg in the substituting group, and 18.0 +/- 2.5 mmHg, 17.8 +/- 2.5 mmHg, and 17.9 +/- 2.6 mmHg in the control group, respectively. There were no significant differences in IOP changes between the two groups (P = 0.74). In the substituting group, ocular irritation was decreased significantly (P = 0.0014) from 63% to 20%. The slight increase of blurred vision from 27% to 37% that occurred in the substituting group was not significant (P = 0.58). In the control group, neither ocular irritation (P = 0.58, from 68% to 57%) nor blurred vision (P = 0.99, from 25% to 21%) was changed. CONCLUSIONS: Substituting brinzolamide for dorzolamide maintained stable IOP with improvement in ocular comfort in patients with glaucoma.     

Effect of dorzolamide and timolol on ocular blood flow in patients with primary open angle glaucoma and ocular hypertension

BACKGROUND: There is evidence that perfusion abnormalities of the optic nerve head are involved in the pathogenesis of glaucoma. There is therefore considerable interest in the effects of topical antiglaucoma drugs on ocular blood flow. A study was undertaken to compare the ocular haemodynamic effects of dorzolamide and timolol in patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT). METHODS: One hundred and forty patients with POAG or OHT were included in a controlled, randomised, double blind study in two parallel groups; 70 were randomised to receive timolol and 70 to receive dorzolamide for a period of 6 months. Subjects whose intraocular pressure (IOP) did not respond to either of the two drugs were switched to the alternative treatment after 2 weeks. Scanning laser Doppler flowmetry was used to measure blood flow in the temporal neuroretinal rim and the cup of the optic nerve head. Pulsatile choroidal blood flow was assessed using laser interferometric measurement of fundus pulsation amplitude. RESULTS: Five patients did not respond to timolol and were changed to the dorzolamide group, and 18 patients changed from dorzolamide treatment to timolol. The effects of both drugs on IOP and ocular perfusion pressure were comparable. Dorzolamide, but not timolol, increased blood flow in the temporal neuroretinal rim (8.5 (1.6)%, p<0.001 versus timolol) and the cup of the optic nerve head (13.5 (2.5)%, p<0.001 versus timolol), and fundus pulsation amplitude (8.9 (1.3)%, p<0.001 versus timolol). CONCLUSIONS: This study indicates augmented blood flow in the optic nerve head and choroid after 6 months of treatment with dorzolamide, but not with timolol. It remains to be established whether this effect can help to reduce visual field loss in patients with glaucoma.     

Efficacy and tolerability of the dorzolamide 2%/timolol 0.5% combination (COSOPT) versus 0.005% (XALATAN) in the treatment of ocular hypertension or glaucoma: results from two randomized clinical trials

PURPOSE: To compare the efficacy of the fixed dorzolamide 2%/timolol 0.5% combination (COSOPT) versus latanoprost 0.005% (XALATAN). METHODS: Two 3-month, parallel group, randomized, observer-masked and patient-masked, multicentre, clinical trials were performed in patients with ocular hypertension or open-angle glaucoma. Study 1 (n=256) was conducted in the United States and Study 2 (n=288) was conducted in Europe/Israel. Patients could be included whether or not they were currently taking ocular hypotensive therapy, and regardless of the effectiveness of any previous therapy. Patients were washed out from their usual ocular hypotensive medications and then those with a baseline intraocular pressure (IOP) >/= 24 mmHg were randomized to either the dorzolamide/timolol combination eye drops twice daily or latanoprost eye drops once daily in both eyes. Efficacy was assessed by daytime diurnal IOP (the mean of measurements made at 0800, 1000, 1400 and 1600 h). RESULTS: At baseline, the mean daytime diurnal IOP was 26.1 mmHg in the dorzolamide/timolol combination group versus 25.6 mmHg in the latanoprost group in Study 1, and 25.3 mmHg in the dorzolamide/timolol combination group versus 24.7 mmHg in the latanoprost group in Study 2. After 3 months, the mean daytime diurnal IOP was 18.9 mmHg for the dorzolamide/timolol combination versus 18.4 mmHg for latanoprost in Study 1, and 17.4 mmHg for the dorzolamide/timolol combination versus 17.5 for latanoprost in Study 2. The difference between treatments in mean IOP change at 3 months was -0.04 mmHg [95% confidence interval (CI) -0.85, 0.77] in Study 1, and -0.57 mmHg (95% CI -1.31, 0.16) in Study 2. The probability that the true difference lay between -1.5 and 1.5 mmHg, the predefined bounds for equivalence, was >0.950 in both studies. Both treatments were well tolerated over 3 months, although ocular stinging occurred more frequently with the dorzolamide/timolol combination. CONCLUSIONS: The dorzolamide/timolol combination and latanoprost were equally effective at lowering IOP.     

Water-drinking test in patients with primary open-angle glaucoma while treated with different topical medications.

OBJECTIVE: Reduction and diurnal stabilization of the intra-ocular pressure (IOP) is the mainstay of treatment for glaucoma. Fluctuations of IOP in glaucomatous patients can also be induced by the osmotic variations caused by water ingestion. Such influence can be studied by means of the water-drinking test (WDT). The aim of this study was to perform the WDT in patients with primary open-angle glaucoma (POAG) while they were being treated with different IOP-lowering medications, to test the effect of drugs with different mechanisms of action on the ability to maintain a stable IOP. METHODS: A total of 280 POAG patients were enrolled, 40 patients per group for each of the tested medications (timolol, dorzolamide, brinzolamide, travoprost,latanoprost, bimatoprost, and brimonidine). After baseline IOP measurement, all patients underwent WDT (1000 mL of water in 10 min). The IOP was measured at 15-min intervals until the return of IOP to baseline values. The main outcomes measured were mean IOP peak, mean IOP percentage increase, and mean time for returning to baseline IOP value. RESULTS: The highest mean IOP peak was found with timolol, whereas no difference was found among the other drugs. The highest mean IOP percentage increase was found with timolol, whereas bimatoprost showed an IOP percentage increase significantly lower than latanoprost, dorzolamide, and brinzolamide. The duration of IOP increase was shortest for bimatoprost and longest for timolol. CONCLUSION: This study suggests that topical medications that enhance outflow (e.g., bimatoprost, latanoprost, travoprost, and brimonidine) may provide, under stressful conditions such as the WDT, better IOP stabilization than medications that decrease aqueous humor inflow, such as timolol and topical carbonic anhydrase inhibitors.     

Comparison of the safety and efficacy of dorzolamide 2% and brimonidine 0.2% in patients with glaucoma or ocular hypertension

PURPOSE: To compare the intraocular pressure (IOP) reduction between dorzolamide 2% and brimonidine 0.2% in primary open-angle glaucoma (POAG) or ocular hypertension (OHT). METHODS: This study was a prospective, double-masked, randomized, crossover comparison of dorzolamide 2% (Trusopt) and brimonidine 0.2% (Alphagan), three times daily during two six-week study periods. The primary endpoint was mean change from baseline in trough IOP and secondary endpoints were mean change from baseline in IOP one and three hours after dosing. T-tests and a repeated-measures ANOVA were used to statistically evaluate the data. RESULTS: Of 43 patients enrolled, 41 completed the first treatment and 38 completed both treatments. Baseline IOP for dorzolamide was 24.3 mm Hg and brimonidine, 24.6 mm Hg (P = 0.9). Mean IOP reduction at trough was similar for both agents, 3.0 mm Hg (P = 0.96). Reductions at one and three hours were comparable (P = ns). Both agents were well tolerated with adverse events consistent with the package inserts. Dorzolamide was associated with more frequent stinging (P = 0.017) and burning (P < 0.001), while brimonidine was associated with more frequent dry eye (P = 0.04). CONCLUSIONS: Dorzolamide and brimonidine, as monotherapy, produced equivalent IOP-lowering efficacy at trough and at one and three hours after instillation, and both were well tolerated.     

Efficacy and side effects of latanoprost monotherapy compared to adding dorzolamide to timolol in patients with glaucoma and ocular hypertension--a three-month randomised study. Spanish Latanoprost Study Group

PURPOSE: To compare the efficacy and safety of latanoprost monotherapy or dorzolamide and timolol in glaucoma patients inadequately controlled on adrenergic beta-receptor antagonist therapy. METHODS: A total of 164 patients with primary open-angle glaucoma, capsular glaucoma or ocular hypertension were included in a three-month, open-label, randomised multicentre study. Patients with open-angle glaucoma were required to have IOP at least 22 mmHg and patients with ocular hypertension were required to have IOP at least 27 mmHg, on treatment with one or two ocular hypotensive drugs of which at least one had to be a beta-blocker. All patients were treated with timolol, 5 mg/ml twice daily, for a 2-4 week run-in period. They were then randomised to latanoprost, 50 microg/ml once daily, or timolol 5 mg/ml plus dorzolamide, 20 mg/ml twice daily. The difference in mean diurnal IOP change from baseline to month 3 was compared in the two groups. RESULTS: When patients were switched to latanoprost, mean diurnal IOP was reduced by 5.2 mmHg (23%) compared to 4.0 mmHg (17%) in the group in which dorzolamide was added to timolol. The difference of 1.2 mmHg was statistically significant (p = 0.005). The majority of adverse events during both treatments were judged as mild. CONCLUSIONS: The results suggest that a switch to latanoprost monotherapy is an alternative to combined treatment with timolol and dorzolamide in patients inadequately controlled on a topical adrenergic beta-receptor antagonist alone.     

Dorzolamide, visual function and ocular hemodynamics in normal-tension glaucoma.

The purpose of this study was to determine how a topical carbonic anhydrase inhibitor, dorzolamide, alters visual function and ocular blood flow in persons with normal-tension glaucoma. Eighteen normal tension glaucoma patients, after washout of other ocular medications, were treated for four weeks with 2% dorzolamide, three times daily. A control group of eleven other normal-tension glaucoma patients received placebo eye drops. Patients were studied before treatment, and after two and four weeks of treatment. Each study included assessment of central visual function (contrast sensitivity), intraocular pressure (IOP), and several aspects of ocular hemodynamics, including measures of retinal arteriovenous passage time, retinal arterial and venous diameters, and flow velocities in the ophthalmic, central retinal, and posterior ciliary arteries. Dorzolamide significantly reduced IOP at two and four weeks (each p<0.01), and at the same time increased contrast sensitivity at both three and six cycles per degree (each p<0.05). Neither of these variables changed significantly in the control group. Dorzolamide also accelerated retinal arteriovenous passage time of fluorescein dye, at constant retinal arterial and venous diameters (p<0.05), but failed to change flow velocities in any retrobulbar vessel. The ability of dorzolamide to improve contrast sensitivity in persons with normal-tension glaucoma may be related to either IOP reduction or altered ocular perfusion.     

Ocular comfort of brinzolamide 1.0% ophthalmic suspension compared with dorzolamide 2.0% ophthalmic solution: results from two multicenter comfort studies. Brinzolamide Comfort Study Group

Two independent, prospective, multicenter, double-masked, parallel group trials were conducted to compare the ocular comfort of brinzolamide 1.0% administered three times daily (t.i.d.) with t.i.d.-dosed dorzolamide 2.0% in patients with primary open-angle glaucoma or ocular hypertension. Patients were randomized to one of two treatment groups, receiving either brinzolamide 1.0% t.i.d. or dorzolamide 2.0% t.i.d. for 1 week. On the last day of dosing, patients received one drop of masked medication in both eyes, and ocular discomfort (burning or stinging) was evaluated by means of a 4-unit ocular discomfort scale. The incidence and extent of ocular discomfort across both treatment groups were analyzed. The results from both studies were confirmatory and demonstrated that the ocular discomfort score for brinzolamide 1.0% was 1.3 units lower than the score for dorzolamide 2.0%, which was both statistically significant and clinically relevant. In addition, a statistically significantly greater percentage of patients reported no ocular discomfort with brinzolamide 1.0% compared with dorzolamide. A greater percentage of patients receiving dorzolamide 2.0% also reported mild, moderate, severe, and very severe ocular discomfort compared with those treated with brinzolamide 1.0%. The most frequent ocular adverse event reported in the brinzolamide group was transient blurred vision, which ranged from 20% to 25%. Overall, adverse events associated with brinzolamide 1.0% and dorzolamide 2.0% were nonserious, were usually mild, and resolved without treatment. The findings of each study independently demonstrated that brinzolamide 1.0% was significantly more comfortable than dorzolamide 2.0% when instilled in the eye.     

The effect of latanoprost on circadian intraocular pressure

The presence of a circadian variation of both intraocular pressure (IOP) and aqueous humor flow has been demonstrated in several studies. It must therefore be considered important to monitor IOP and evaluate the efficacy of ocular hypotensive drugs over the 24 hours of the day. The efficacy of latanoprost on IOP during both day and night has been evaluated and the most important results from four such studies are reviewed. The studies reviewed here clearly demonstrate that topical administration of latanoprost 0.005% once daily provided a steady reduction of the IOP during both day and night. Given as a single dose to healthy volunteers, latanoprost resulted in a sustained effect with a significant IOP reduction over 24 hours, and the reduction was still present, however less pronounced, even after 48 hours. Latanoprost administered once daily for 4 weeks to patients with glaucoma or ocular hypertension was more effective in reducing the IOP over 24 hours than timolol gel solution 0.5% once daily, timolol aqueous solution 0.5% twice daily, or dorzolamide 2% three times daily. Latanoprost applied once daily thus provided a better effect on the IOP together with a stable and sustained IOP reduction during both day and night.     

The efficacy and safety of brinzolamide 1% ophthalmic suspension (Azopt) as a primary therapy in patients with open-angle glaucoma or ocular hypertension. Brinzolamide Primary Therapy Study Group

A randomized, multicenter, double-masked, prospective, parallel study was designed to establish the intraocular pressure (IOP)-lowering efficacy, safety, and tolerability of brinzolamide 1.0% (Azopt) as a primary therapy compared with dorzolamide 2.0% (Trusopt) and placebo in patients diagnosed with open-angle glaucoma (with or without a pseudoexfoliative or a pigmentary dispersion component) or ocular hypertension. Brinzolamide 1.0%, dosed two times (b.i.d.) and three times (t.i.d.) a day, dorzolamide 2.0% (t.i.d.), and placebo (t.i.d) were administered to patients during a 3-month treatment period. Diurnally corrected IOP reduction from baseline, including peak and trough times, was the primary end point. Sample sizes were chosen to establish statistical equivalence between treatments. Mean IOP changes observed on treatment were as follows: -3.4 mm Hg (-13.2%) to -4.1 mm Hg (-16.7%) with brinzolamide 1.0% b.i.d.; -4.1 mm Hg (-16.6%) to -4.8 mm Hg (-19.1%) with brinzolamide 1% t.i.d.; and -4.3 mm Hg (-16.9%) to -4.9 mm Hg (-20.1%) with dorzolamide 2.0%. IOP reductions after administration of brinzolamide 1.0% b.i.d. and t.i.d. were equivalent to each other and also clinically and statistically equivalent to those with dorzolamide 2.0% t.i.d. The incidence of ocular discomfort (burning and stinging) upon instillation was significantly higher for dorzolamide (10.7%) than brinzolamide (b.i.d. or t.i.d., 3.0% each). The most frequent non-ocular event reported was taste perversion, which was less (3.7%) with brinzolamide 1.0% b.i.d., but brinzolamide t.i.d. was similar to dorzolamide t.i.d. (6.8% vs. 5.3%). Brinzolamide 1.0% b.i.d., brinzolamide 1.0% t.i.d., and dorzolamide 2.0% t.i.d. equaled each other in IOP-lowering efficacy, and brinzolamide was significantly more comfortable than dorzolamide upon instillation.     

Short-term ocular tolerability of dorzolamide 2% and brinzolamide 1% vs placebo in primary open-angle glaucoma and ocular hypertension subjects

PURPOSE: To compare ocular tolerability of dorzolamide 2%, brinzolamide 1%, and placebo given three times daily. METHODS: A prospective, double-masked, three-centre, crossover comparison in which 25 ocular hypertensive or primary-open angle glaucoma subjects were randomized to receive dorzolamide, brinzolamide, or placebo three times daily for 3 days. Intraocular pressure, visual acuity, a visual analogue scale, and ocular and systemic symptom queries were completed at the end of each period. RESULTS: After chronic dosing, there was a significant difference in ocular pain on the visual analogue scale among the groups at the 10-s postinstillation time point with dorzolamide having the highest level (22.5+/-28.9) compared to brinzolamide (5.0+/-8.7) or placebo (3.2+/-10.4) (P=0.0006). No differences between groups were observed preinstillation nor following dosing at 3 or 10-min postinstillation. On the initial instillation, the 10-s postinstillation pain was rated as 43.3+/-77.1, which was significantly higher than after chronic dosing (P=0.017). On the ocular symptom query, dorzolamide had the highest incidence of burning/stinging and redness compared to the other groups, but was generally characterized as mild. There were no significant differences in the visual acuity at any time point. CONCLUSIONS: This study suggests that subjects treated with dorzolamide suffer more ocular pain upon instillation compared to brinzolamide or placebo. However, pain symptoms are fewer following chronic dosing and are generally characterized as mild.     

A controlled clinical trial of Dorzolamide: a single-centre subset of a multicentre study

Purpose: To assess the safety and intraocular pressure (IOP)-lowering activity of 2% dorzolamide (topical carbonic anhydrase inhibitor), compared to 0.5% timolol and 0.5% betaxolol eyedrops.
Methods: A parallel, masked, randomised one-year clinical trial was conducted in 16 patients with open-angle glaucoma or ocular hypertension, being a subset of a multicentre study which enrolled 523 subjects. Patients had IOP > 22 mmHg in one eye at baseline following washout of ocular hypotensive medications and were then randomised in a 3:l:l ratio to receive 2% dorzolamide thrice daily, 0.5% timolol twice daily or 0.5% betaxolol twice daily respectively. IOP was measured at Hour 2 (morning peak), Hour 5 and Hour 8 (afternoon trough for dorzolamide) at baseline, Weeks 2 and 4 and Months 2, 3, 6, 9 and 12.
Results: Topical dorzolamide 2% solution was well tolerated and safe. Mean IOP for dorzolamide at Hour 2 was 29.1 mmHg at baseline and 20.8 mmHg on treatment at one year, a 28.5% change. Mean IOP for dorzolamide at Hour 8 was 24.5 mmHg at baseline and 20.2 mmHg on treatment at one year, a 17.6% change. Comparable percent changes for timolol and betaxolol were 43.2/25.7 mmHg at Hour 2 and 21.9/13.5 mmHg at Hour 8 respectively.
Conclusions: Dozolamide 2% given thrice daily was well tolerated and safe, with a clinically significant effect on IOP comparable to betaxolol 0.5% twice daily, but not as great as timolol 0.5% twice daily.     

Comparison of latanoprost monotherapy to dorzolamide combined with timolol in patients with glaucoma and ocular hypertension — A 3-month randomised study

· Background: The purpose of the study was to compare the effects on intraocular pressure (IOP) of adding dorzolamide to timolol or of switching from timolol to latanoprost monotherapy in glaucoma patients inadequately controlled on timolol. · Methods: The study was designed as a 3-month randomised, open-label, multicentre study comprising 183 patients with primary open-angle glaucoma, capsular glaucoma with IOP above 22 mmHg on treatment with one or two ocular hypotensive drugs, or ocular hypertension with IOP above 27 mmHg. After a 2- to 4-week run-in period on timolol, 0.5% twice daily, the patients were randomised to treatment with either latanoprost, 0.005% once daily, or the combination of timolol, 0.5% twice daily, and dorzolamide, 2% twice daily. The mean diurnal IOP after 3 months of treatment was compared with baseline. · Results: Switching from timolol to latanoprost reduced mean diurnal IOP by 4.5±0.2 mmHg (mean±SEM, ANCOVA; 20%), and adding dorzolamide to timolol reduced mean diurnal by 4.4±0.2 mmHg (mean±SEM, ANCOVA; 20%). No serious side effects were observed with either treatment. · Conclusion: Latanoprost monotherapy can be an alternative to combined treatment with two aqueous flow suppressors in patients whose IOP is insufficiently controlled by timolol alone. Received: 30 March 1999 Revised version received: 27 May 1999 Accepted: 7 June 1999     

A comparison of the effects of dorzolamide/timolol fixed combination versus latanoprost on intraocular pressure and pulsatile ocular blood flow in primary open-angle glaucoma patients

PURPOSE: To evaluate the effects of dorzolamide/timolol fixed combination (D/T) compared to latanoprost on intraocular pressure (IOP) and pulsatile ocular blood flow (POBF) in primary open-angle glaucoma (POAG) patients. METHODS: Thirty patients with POAG were randomized in an open-label, cross-over study. Intraocular pressure reduction was achieved by 4 weeks medical therapy with D/T twice daily or latanoprost 0.005% dosed once in the evening. During a 4-week run-in and a 4-week wash-out period between study arms, patients ceased use of all other glaucoma medications and used timolol maleate 0.5% twice daily. Primary efficacy variables were IOP and POBF. RESULTS: There was no difference in baseline IOP and POBF parameters between the two study arms. Both D/T and latanoprost statistically significantly reduced IOP by 4.6 mmHg (p < 0.0001) and 3.75 mmHg (p < 0.0001) and increased POBF by 2.048 microl/second (p = 0.0030) and 2.147 microl/second (p = 0.0009), respectively. Repeated measures anova detected significant changes in POBF with treatment (p = 0.0361). Dorzolamide/timolol fixed combination statistically significantly increased pulse volume by 0.767 microl (p = 0.0087), while latanoprost therapy had no significant effect (p = 0.2407). CONCLUSIONS: Both drugs had similar effects in terms of IOP reduction. Dorzolamide/timolol significantly increased pulse volume while latanoprost had no effect. Further studies are necessary to establish whether the enhancement of choroidal blood flow can prevent glaucoma progression.     

Circadian intraocular pressure control with dorzolamide versus timolol maleate add-on treatments in primary open-angle glaucoma patients using latanoprost

PURPOSE: To compare the 24-hour efficacy of dorzolamide and timolol maleate administered twice daily to primary open-angle glaucoma patients whose intraocular pressure (IOP) could not be adequately controlled with latanoprost monotherapy. METHODS: In this double-blind prospective crossover clinical comparison trial, 36 primary open-angle glaucoma patients with uncontrolled IOP despite treatment with latanoprost applied once daily were administered timolol and dorzolamide twice daily. The treatment sequence was randomized. All patients underwent measurements for four 24-hour tonometric curves: at baseline and after each 4-week period of treatment. The IOP measurements were taken at 06:00, 09:00, 12:00, 15:00, 18:00, 21:00, 24:00 and 03:00 h. The between-group differences were tested for significance by means of parametric analysis of variance at each time point and circadian curve. The peak values within circadian curve were defined. The mean of the exact amount and percentage of additional IOP reductions from baseline were evaluated and success rates (a minimum of 10% reduction) were determined for both drug regimens. RESULTS: The mean peak/circadian curve IOPs were 23.4 +/- 2.2/21.8 +/- 2.2 mm Hg at dorzolamide baseline, 23.3 +/- 2.2/21.7 +/- 2.1 mm Hg at timolol baseline, and reduced to 20.2 +/- 1.7/18.7 +/- 1.7 mm Hg and 20.7 +/- 2.4/19.4 +/- 1.6 mm Hg, respectively. When added to latanoprost, both dorzolamide and timolol lowered IOP at circadian curve significantly (p < 0.05). Dorzolamide reduced baseline IOP values at each time point. Timolol also significantly reduced baseline IOP values at all time points except at 03:00. The mean of the exact amount and percentage of reduction in IOP at circadian curve and 5 out of 8 time points were significantly greater with dorzolamide add-on treatment (p < 0.05). The successful reduction rates were 86% for the dorzolamide group and 61% for the timolol group (p = 0.016; chi(2) test). CONCLUSION: Both of the combinations are effective in lowering IOP, the exact amount and percentage of reduction is greater with the latanoprost + dorzolamide regimen, especially at night-time.     

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

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.

Keywords: dorzolamide; timolol; intraocular pressure; glaucoma; ocular hypertension