[Single dose administration in therapy of glaucoma. Comparison of costs with multiple dose]

Preservatives in antiglaucomatous agents can irritate the conjunctiva and may lead to allergic reactions. Preservative-free single-dose applications of glaucoma medications have increasingly become available. We analysed the therapy costs for single-dose containers per eye and per year and compared them with those for multidose containers. The data were calculated from prices taken from the German pharmacy index, applications per day and number of drops in the container. The drop volume ranged from 34.3 microliters to 48.0 microliters for single-dose containers and from 29.2 microliters to 40.0 microliters for multidose containers. The annual cost of therapy with beta-adrenergic antagonist preparations was DM 42.59-DM 80.78 for multidose containers and DM 162.73-DM 242.42 for single-dose containers. The cost of therapy with philocarpine was DM 21.55 but DM 233.92 for single-dose containers. The cost of combination therapy with beta-adrenergic antagonist preparations and pilocarpine ranged from DM 67.92 to DM 214.33 for multidose containers and from DM 408.15 to DM 428.95 using single-dose containers. Therapy with preparations in single-dose containers is more expensive than with multidose containers (+161 to +1169%). Preparations in single-dose containers without preservatives can have advantages, but the higher costs necessitate careful selection of the patients.