A prospective and multicenter safety-monitoring study of a short up-dosing schedule of immunotherapy with a mass-units-standardized extract of mites.

A prospective, multicenter pharmacovigilance study was carried out to evaluate the safety of a new 7-dose treatment schedule of subcutaneous immunotherapy as opposed to the conventional 13 doses normally recommended. The study was carried out in 14 centers and included 261 patients (children and adults) with respiratory allergic disease due to sensitization to mites (Dermatophagoides pteronyssinus and/or farinae). A total of 2290 doses were administered under the direct supervision of the participating specialists. One hundred and ten reactions in 63 patients (24.1%) were recorded, representing 4.8% of the total doses administered. Most of the reactions (98) were local. Only 12 were systemic (0.5% of the administered doses) and occurred in 10 patients (3.8% of the sample). Ten reactions reverted quickly with rescue medication. The maintenance dose had to be lowered in one patient and another patient was withdrawn from the study after suffering two asthmatic crises after two consecutive doses. In view of the results obtained, we can conclude that the new schedule shows an acceptable tolerance profile and does not present a greater risk of reactions than the conventional scheme of 13 doses using an identical extract. Moreover, the new schedule represents substantial savings in the number of doses and visits required to reach the maintenance dose.