Yet Another Doctor Blog On The Internet

Gout and hyperuricaemia.

2017-05-22

Timolol maleate, levobunolol, metipranolol, and carteolol have similar effectiveness in lowering intraocular pressure; however, levobunolol and timolol gel forming solution may have an advantage of once-daily dosing. Studies have not been published comparing the clinical efficacy of timolol hemihydrate with that of other ocular beta-blockers. Metipranolol is cost effective in treating primary open-angle glaucoma; however, it has been associated with more ocular burning, stinging, and granulomatous anterior uveitis than other agents. The intrinsic sympathomimetic activity of carteolol has not yet displayed a definite advantage over the other agents in terms of optic disk perfusion and systemic adverse effects. The control of intraocular pressure with betaxolol has not always been as good as with timolol; however, betaxolol has some advantages over timolol and the other topical beta-blockers in terms of systemic adverse effects.

In a 4-year, double-masked, parallel, multicenter study comparing the efficacy and safety of levobunolol and timolol, 391 patients with open-angle glaucoma or ocular hypertension were randomly assigned to receive masked 0.5% or 1% levobunolol, or 0.5% timolol, twice daily. Mean decreases in intraocular pressure (IOP) over 4 years of therapy were 7.1, 7.2, and 7.0 mmHg for 0.5% levobunolol, 1% levobunolol, or 0.5% timolol, respectively. Little attenuation of ocular hypotensive efficacy occurred. The 4-year efficacy failure rate for the three groups, which did not differ from each other, was approximately 30%. Adverse experiences requiring cessation of therapy occurred in an additional 10% of patients. The vast majority of efficacy failures (79/95) and of adverse events (33/37) requiring removal from the study occurred during the first 2 years. Overall mean decreases in heart rate for the 4 years ranged from 3 to 6 beats per minute for all treatment groups; overall mean decreases in systolic and diastolic blood pressure ranged between 1 and 2 mmHg. The authors concluded that levobunolol is relatively effective and relatively safe for the long-term (4-year) treatment of elevated IOP.

The intraocular pressure rise after cataract extraction strongly depends on the surgical technique and to a lesser extent, on the surgeon's experience. At least for phacoemulsification, the effect of the prophylactic medication used in this study is small and appears to be clinically irrelevant.

Systemically, levobunolol is as effective as propranolol for cardiovascular indications, with a greater potency and greater duration of action. Ocularly, levobunolol is as effective and as safe as topical timolol for the long-term treatment of elevated IOP. The utility of topical levobunolol as an additional, effective beta-blocker for the treatment of glaucoma will be determined by additional research and use by ophthalmologists in countries where levobunolol is approved.

Two concentrations of levobunolol (0.5% and 1%) and one concentration of timolol (0.5%) were evaluated for the control of elevated intraocular pressure (IOP) in a double-masked, randomized study. Fifty-one patients received one of the three study treatments in both eyes bid for one year. Both drugs were equally effective in reducing IOP: The overall reduction in mean IOP was slightly more than 9 mm Hg in all three treatment groups. Levobunolol was as safe and effective as timolol for the long-term control of elevated IOP.

To better inform physicians and patients about pharmaceutical issues relating to the correct usage or storage of ophthalmic products used to manage glaucoma, the authors reviewed the US Food and Drug Administration requirements for sterile ophthalmic preparations, together with the United States Pharmacopeia 24. They also reviewed the Ophthalmic Physicians Desk Reference (2000 edition) for pharmaceutical information regarding branded glaucoma-solution products.

Forty patients with chronic open-angle glaucoma or ocular hypertension participated in this randomized double-masked clinical trial. The patients instilled either 0.5% Levobunolol or 0.5% Timolol into each eye twice daily for three months. Levobunolol produced an overall decrease in mean intraocular pressure of approximately 7 mmHg, while Timolol produced an overall decrease of approximately 5 mmHg but no significant difference has been proved. Intraocular pressure was inadequately controlled in five patients in each treatment group. Both drugs caused heart rate decreases that were judged to be of limited clinical significance. Levobunolol was found to be as safe and effective as Timolol for the treatment of patients with open-angle glaucoma as for those with chronic ocular hypertension.

Eighteen adult patients were enrolled in the study, with nine in the topical levobunolol group and nine in the oral paracetamol group. In the levobunolol group, the mean reduction in intraocular pressure at day 7 was 7.5 mmHg (P < 0.008) and at day 14 was 9.1 mmHg (P < 0.005), from a mean baseline intraocular pressure of 29.6 mmHg. The corresponding figures for the paracetamol group were 8.8 mmHg (P < 0.0004) at day 7 and 6.5 mmHg (P < 0.004) at day 14, from a mean baseline intraocular pressure of 29.4 mmHg. Both study regimens were well tolerated. No serious treatment-related adverse events were reported in either of the treatment groups. Liver function tests, systolic/diastolic blood pressure, or heart rate remained unchanged in both groups during the 2 weeks of the study. In the laboratory study, paracetamol 1 mg/mL in phosphate-buffered solution (pH 7.4) showed acceptable flux rates. Steady-state levels were achieved within 12 hours, thus confirming that paracetamol penetrates the cornea well.