Multiple action drugs, such as azelastine, epinastine, ketotifen and olopatadine, have recently been suggested to combine antihistaminic effect, mast cell stabilization and anti-inflammatory action. This pharmaceutical class is, therefore, rapidly becoming the first choice for prevention and treatment for allergic conjunctivitis.
Increasing in-vitro studies have been performed to investigate the mast-cell-stabilizing effect of multiple action drugs. Most of the study results agree that these drugs are able to inhibit histamine and several neoformed mediators, including cytokines and arachidonic acid-derived products, from mast cells. However, the mechanisms of action have not yet fully been elucidated. Most of the results from clinical trials as well as the in-vivo experimental studies, including the conjunctival provocation model, support the evidence of a stabilizing effect of these drugs.
Evidence of a different inhibitory effect of multiple action compounds on the pro-inflammatory mediators released from the mast cells suggests the possibility to target different phases of the allergic reaction, leading to a potential improvement in the management of allergic patients.
aCIR Laboratory of Ophthalmology, University Campus Bio-Medico, Italy
bIRCCS-G.B. Bietti Eye Foundation, Rome, Italy
Correspondence to Stefano Bonini, MD, Full Professor, Department of Ophthalmology, University Campus Bio-Medico, Via Alvaro del Portillo 21, Rome 00128, Italy Tel: +39 06225419185; fax: +39 0622541456; e-mail: email@example.com