Are antihistamines useful in managing asthma?

Area of Science:

• Pharmacology
• Immunology
• Respiratory Medicine

Background:

• Antihistamines are being investigated for their anti-asthmatic properties.
• Emerging evidence indicates anti-inflammatory effects beyond histamine receptor antagonism, including suppression of cell adhesion molecule expression.
• The link between upper and lower airway allergic inflammation supports evaluating antihistamines in allergic asthma and rhinitis.

Purpose of the Study:

• To evaluate the anti-inflammatory and anti-asthmatic effects of antihistamines.
• To assess the impact of antihistamines on bronchial hyperresponsiveness.
• To explore the efficacy of combining antihistamines with leukotriene receptor antagonists.

Main Methods:

• Clinical evaluation of antihistamines in patients with allergic asthma and rhinitis.
• Assessment of lung function and asthma symptom control.
• Bronchial challenge tests (methacholine and mannitol) to measure hyperresponsiveness.
• Studies on the combined effects of antihistamines and leukotriene receptor antagonists.

Main Results:

• Antihistamines demonstrate clinically relevant anti-asthmatic properties.
• Improvements observed in asthma symptom control and lung function measurements.
• Evidence of bronchoprotection against methacholine and mannitol challenges.
• Combination therapy with antihistamines and leukotriene receptor antagonists shows synergistic anti-asthmatic effects, potentially comparable to inhaled corticosteroids.

Conclusions:

• Antihistamines possess significant anti-asthmatic effects, including anti-inflammatory actions and bronchoprotection.
• Combined antihistamine and leukotriene receptor antagonist therapy offers superior asthma control.
• These findings support the expanded role of antihistamines in asthma management.