Intraocular pressure control with latanoprost/timolol and travoprost/timolol fixed combinations : a retrospective, multicentre, cross-sectional study

Balancing efficacy and tolerability of prostaglandin analogues and prostaglandin-timolol fixed combinations in primary open-angle glaucoma

BACKGROUND

Lowering intraocular pressure (IOP) is currently the only therapeutic approach that preserves visual function in primary open-angle glaucoma. In making treatment decisions for first- and second-line therapy, the clinician needs to provide an appropriate balance of efficacy and tolerability. Prostaglandin analogues (PGAs) are frequently used as first-line monotherapy, because of their efficacy and low risk of systemic side effects. Similarly, PGA-based fixed combinations are frequently used in patients who progress or fail to achieve the target IOP.

SCOPE

We have reviewed the literature on the management of primary open-angle glaucoma with PGAs, both as monotherapies and in fixed combinations.

FINDINGS

In the clinical trial and meta-analysis data identified, bimatoprost 0.03% seems to be associated with a greater overall ability to lower IOP compared with latanoprost, travoprost or tafluprost, at the cost of a slightly higher incidence of conjunctival hyperaemia. Studies indicate that patients' adherence to treatment is generally better with PGAs than with many other monotherapies. In patients requiring more than one IOP-lowering agent, fixed combination treatments may provide improved adherence and tolerability benefits compared with concomitant use of individual treatments. Bimatoprost/timolol fixed combination appears to be slightly more efficacious than latanoprost/timolol or travoprost/timolol, and tolerability differences between the fixed combinations appear to be slight, probably because the addition of timolol to the PGA component lessens the associated hyperaemia. Surveys on EU physician attitudes appear largely in line with these clinical data.

CONCLUSION

An appropriate balance between efficacy and tolerability ensures optimum IOP lowering and reduces the risk of non-adherence. PGAs largely fulfil this need as monotherapies and as components of combinations.

Role of fixed combinations in the management of open-angle glaucoma

The first-line option for lowering intraocular pressure (IOP) is a single hypotensive agent, but patients frequently require additional IOP-lowering agents to reach their target pressures. Disadvantages of this multi-therapy approach include washout effect, inconvenience and poor adherence. Fixed combinations (FCs) combine two or more hypotensive agents in a single bottle, providing a convenient once-daily therapy, which tends to improve adherence. FCs generally offer equivalent efficacy to concomitant use of the individual components, with equivalent or superior tolerability. Studies also show that FCs can be more cost effective than nonfixed combinations. In terms of optimizing IOP control, minimizing visual field deterioration, preventing visual disability and minimizing associated healthcare costs, FCs are an important component of glaucoma management.

Treatment persistence and cost-effectiveness of latanoprost/latanoprost-timolol, bimatoprost/bimatoprost-timolol, and travoprost/travoprost-timolol in glaucoma: an analysis based on the United Kingdom general practitioner research database

OBJECTIVE

To compare treatment persistence and costs with 3 glaucoma treatment sequences (first-line/second-line): latanoprost/latanoprost-timolol (LLT), bimatoprost/bimatoprost-timolol (BBT), and travoprost/travoprost-timolol (TTT), derived from the UK General Practitioner Research Database (UK-GPRD).

METHODS

Patient records referring to ocular hypertension, topical glaucoma treatment, surgery, or laser therapy were extracted. Patients prescribed LLT, BBT, or TTT sequences were selected. Treatment failure was inferred from glaucoma prescription change (adding or removing a topical treatment, surgery, or laser therapy). Treatment durations preceding failure were compared by applying Wilcoxon's test to survival curves. Adjustment on confounding variables was performed with a Cox model and a propensity score method. Unit costs were estimated from a UK National Health Service perspective.

RESULTS

A total of 1592 patients received LLT, 110 BBT, and 114 TTT. Their mean age was 68 years and the sex ratio almost 1 male:1 female. No significant demographic or comorbidity differences were observed between treatment sequences. Treatment persistence at 36 months was achieved in 60.0% of LLT, 55.5% of BBT, and 70.3% of TTT patients (P = 0.005). Resources consumed and associated monthly costs were significantly less for the TTT group (£17.74) compared with BBT (£21.30) and LLT (£22.37) groups.

CONCLUSION

Analysis of data obtained from the UK-GPRD suggests that the TTT treatment sequence achieved longer treatment persistence at lower cost than LLT and BBT.

Clinical utility and differential effects of prostaglandin analogs in the management of raised intraocular pressure and ocular hypertension

Prostaglandin analogs (PGA) are powerful topical ocular hypotensive agents available for the treatment of elevated intraocular pressure (IOP). Latanoprost 0.005% and travoprost 0.004% are prodrugs and analogs of prostaglandin F2α. Bimatoprost 0.03% is regarded as a prostamide, and debate continues as to whether it is a prodrug. The free acids of all 3 PGAs reduce IOP by enhancing uveoscleral and trabecular outflow via direct effects on ciliary muscle relaxation and remodeling of extracellular matrix. The vast majority of clinical trials demonstrate IOP-lowering superiority of latanoprost, bimatoprost and travoprost compared with timolol 0.5%, brimonidine 0.2%, or dorzolamide 2% monotherapy. Bimatoprost appears to be more efficacious in IOP-lowering compared with latanoprost, with weighted mean difference in IOP reduction documented in one meta-analysis of 2.59% to 5.60% from 1- to 6-months study duration. PGAs reduce IOP further when used as adjunctive therapy. Fixed combinations of latanoprost, bimatoprost or travoprost formulated with timolol 0.5% and administered once daily are superior to monotherapy of its constituent parts. PGA have near absence of systemic side effects, although do have other commonly encountered ocular adverse effects. The adverse effects of PGA, and also those found more frequently with bimatoprost use include ocular hyperemia, eyelash growth, and peri-ocular pigmentary changes. Iris pigmentary change is unique to PGA treatment. Once daily administration and near absence of systemic side effects enhances tolerance and compliance. PGAs are often prescribed as first-line treatment for ocular hypertension and open-angle glaucoma.