Cost Minimisation Study of the Impact of Generic Drugs on Glaucoma Management: 1-year Indian Experience

Abstract

Aim: To study the medication costs of various topical glaucoma medications using data collected from real world use by patients.
Methods: Patients with primary open angle glaucoma treated at glaucoma clinics in 5 hospitals (1 rural and 4 urban) in northern India from 1 January to 30 June 2008 were enrolled. The number of days each bottle of medication lasted was recorded, and the mean cost per day was computed from the maximum retail price and mean number of days each medication lasted.
Results: 790 of 801 eligible patients completed the study. The mean number of days that a bottle of medication lasted was found to be highest for Xalatan® and Xalacom® at 35.23 days and 35.00 days, respectively. The brand name prostaglandin analogues all lasted for a mean of more than 30 days: Xalatan, 35.23 days (SD, 4.14 days); Lumigan®, 31.37 days (SD, 5.31 days); and Travatan®, 34.84 days (SD, 6.51 days), while the generic eye drops lasted for about 21 days: latanoprost, 20.69 days (SD, 3.69 days) and bimatoprost, 21.39 days (SD, 4.34 days). The cost of the generic medication was less than the brand name medication in all groups (for example, bimatoprost, Indian rupees 9.76 versus Indian rupees 12.33) except for brimonidine/timolol (Indian rupees 8.73 versus Indian rupees 8.66). Further analysis in 2009 showed that, for latanoprost, brimonidine and brimonidine/timolol, the difference between the brand name and generic medications decreased in 2009 over 2008 (in the latanoprost group, the cost difference over the year reduced from Indian rupees 592 in 2008 to Indian rupees 523 in 2009); the cost difference for bimatoprost increased from 2008 to 2009.
Conclusion: When both cost and number of days a bottle lasts were considered over the long term, use of generic medications might not minimise the cost of glaucoma medical management by much when compared with the brand name medication.