Cost-minimisation study of dorzolamide versus brinzolamide in the treatment of ocular hypertension and primary open-angle glaucoma: in four European countries.
OBJECTIVE
Cost is an issue when prescribing two drugs with equivalent efficacy. We compared the direct medical costs of topical brinzolamide 1% (twice a day or three times daily) with topical dorzolamide 2% (twice a day or three times daily) in France, Italy, Portugal and Spain in patients with ocular hypertension or primary open-angle glaucoma.


METHODS
Three double-blind, controlled, randomised trials (with a study duration of 3 months) compared the response rate of brinzolamide twice a day or three times daily versus dorzolamide three times daily, and the response rate of brinzolamide-timolol twice a day versus a dorzolamide-timolol combination twice a day. A fourth double-blind randomised trial (with a duration of 12 months) compared brinzolamide twice a day and three times daily with timolol monotherapy. Local tolerance was compared in two dedicated studies. Rates of switching to a new medication regimen were evaluated through a US health maintenance organisation database. In case of treatment failure, the patients were treated with latanoprost. A model was developed to value direct medical costs over 3 months. The economic perspective was that of the third-party payer and the patient, and included direct medical costs (reimbursed part plus co-payment).


METHODS
Patients with ocular hypertension and/or primary open-angle glaucoma who had not responded to or could not tolerate beta-blocker therapy.


METHODS
The daily direct medical costs of therapy with the two drugs.


RESULTS
As monotherapy, brinzolamide twice daily and three times daily was found to be as efficacious as dorzolamide three times a day. Brinzolamide twice daily plus timolol was also as efficacious as a combination of dorzolamide and timolol twice a day. Stinging of the eye upon instillation with brinzolamide was experienced by fewer patients than with dorzolamide (p < 0.0001). The likelihood of patients treated with dorzolamide changing therapy was 1.28 times greater than that for those treated with brinzolamide. The size of the brinzolamide drop is 18.7% smaller than that of dorzolamide allowing seven more therapy days per bottle with brinzolamide twice daily than with dorzolamide monotherapy, and five more days when brinzolamide is used three times a day. The direct medical costs for patients treated with brinzolamide were lower in all four European countries when drop size was taken into account than for those treated with dorzolamide. Sensitivity analyses confirmed the robustness of our findings.


CONCLUSIONS
Because brinzolamide can be prescribed twice daily in monotherapy and because fewer patients treated with brinzolamide switch therapy due to local intolerance, our model suggests that brinzolamide is a cost-saving alternative to dorzolamide.
Rouland
Jean-Francois
JF
Hôpital Huriez, Service d'Ophtalmologie, Lille Cedex, France.
Le Pen
Claude
C
Gouveia Pinto
Carlos
C
Berto
Patrizia
P
Berdeaux
Gilles
G
D000287:Administration, Topical; D002257:Carbonic Anhydrase Inhibitors / Q000191:economics / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D017850:Economics, Pharmaceutical; D005060:Europe; D005902:Glaucoma, Open-Angle / Q000188:drug therapy* / Q000191:economics; D006801:Humans; D009798:Ocular Hypertension / Q000188:drug therapy* / Q000191:economics; D016032:Randomized Controlled Trials as Topic; D013449:Sulfonamides / Q000191:economics / Q000627:therapeutic use*; D013843:Thiazines / Q000191:economics / Q000627:therapeutic use*; D013876:Thiophenes / Q000191:economics / Q000627:therapeutic use*
D002257:Carbonic Anhydrase Inhibitors; D013449:Sulfonamides; D013843:Thiazines; D013876:Thiophenes; C111827:brinzolamide; C062765:dorzolamide