Safety and pharmacoeconomics of a cluster administration of mite immunotherapy compared to the traditional one.

Accelerated schedules of administration of immunotherapy (rush or clustered) allow to reach the maintenance dosage in shorter times with respect to traditional schedules. Nowadays formal assessments of the safety and economic aspects of those schedule lack for inhalant allergens. We compared in a prospective randomized open study a cluster and a traditional immunotherapy with standardized mite extracts. Thirty eight adult patients with persistent allergic rhinitis due to mites were randomized to receive either a traditional (N= 19) or a cluster (N=19) up-dosing scheme, lasting 13 and 3 weeks respectively. Side effects were carefully evaluated and recorded by physician and costs were calculated as well. In the cluster and traditional updosing 148 and 241 injections were given respectively. With the cluster up-dosing there were 8 local reactions (15.9% of patients and 5.4% of injections). With the traditional schedule 6 local reactions (31.5 % of patients and 2.4% of injections) occurred. There was no difference between the two treatments in occurrence of side effects per patient and per injection (chi-square 1.31 and 2.23, p= NS). No systemic reaction was recorded. Considering the cost of the extract, the cost of injections and the time spent, the cluster regimen resulted in a global spare of 244.95 euros per patient in the build-up phase. The cluster up-dosing is as safe as the traditional one and allows a significant economical save.