Antihistamine premedication in specific cluster immunotherapy: a double-blind, placebo-controlled study

Area of Science:

• Allergy and Immunology
• Pharmacology

Background:

• Specific immunotherapy for allergic diseases carries a risk of systemic side effects.
• Cluster immunotherapy involves a dose-escalation phase that can trigger reactions.

Purpose of the Study:

• To evaluate if loratadine pretreatment can decrease the incidence and severity of systemic reactions during cluster immunotherapy for pollen allergy.

Main Methods:

• A double-blind, placebo-controlled study involving 45 pollen-allergic patients.
• Patients received standardized birch or grass pollen extract immunotherapy with either loratadine (10 mg) or placebo 2 hours before injections.
• The study tracked systemic reactions during the dose-increase phase over seven visits.

Main Results:

• Fewer patients experienced systemic reactions in the loratadine group (33%) compared to placebo (79%).
• The loratadine group had significantly fewer dose reductions due to systemic reactions (9 vs 25).
• Systemic reactions, particularly urticaria, were less severe in the loratadine group.

Conclusions:

• Loratadine pretreatment appears effective in mitigating the number and severity of systemic reactions during specific cluster immunotherapy.
• This strategy may enhance patient safety and adherence to immunotherapy protocols.