With the aim of evaluating tolerance to new shorter initiation schedules in subcutaneous immunotherapy everyday clinical practice, a study was carried out using Pangramin Plus® with initiation periods between 3 (Cluster) and 6 (Plus) weeks.
All the information was processed retrospectively and both systemic (SR) and local (LR) adverse reactions occurring between September 2002 and February 2003 were recorded.
A total of 353 patients (261 Plus and 91 Cluster) were included and 2,886 doses were administered (2,166 in initiation and 720 in maintenance). Of these, 800 were with Grass mix extract, 1,141 Grass mix + Olea, 273 Olea, 73 Dermatophagoides mix and 599 Dermatophagoides pteronyssinus.
As regards adverse reactions (AR), 2.8% of patients showed SR and 4.8% LR, 1.2% of doses caused some type of reaction (SR and LR in 0.3% and 0.9%, respectively). The initiation schedule, first dose or allergens resulted in no significant differences in the frequency of adverse reactions. The Grass mix extract showed the highest frequency
of AR.
Sixty-seven percent of SR and 68% of LR were delayed. 64% of these reactions resolved spontaneously while the rest responded favourably to treatment. Adrenaline was administered on one occasion for immediate asthma.
There were no cases of anaphylactic shock, hospitalisation or life-threatening situations.
Pangramin Plus® tolerance, therefore, can be classified as good, similar to conventional schedules, but with the benefits of shorter initiation schedules.

Key words: Subcutaneous immunotherapy, tolerance, short initiation schedule.