Doqualast is an antiasthmatic and antiallergic agent. It has a mode of antiallergic action similar to that of disodium cromoglycate and inhibits antigen-induced mediator release by interfering with the calcium transport required for histamine secretion across the mast cell membrane. In rabbits, no embryotoxic or teratogenic effects of doqualast were observed. The concomitant use of doqualast and theophylline might cause drug interaction. Doqualast is thought to increase the blood free fraction of concomitantly used theophylline and to accelerate elimination of theophylline from blood.

Gemilukast (ONO-6950) is an orally active compound that has been evaluated for the treatment of asthma. It is an CysLT1 and CysLT2 antagonist. Activation of CysLT2 receptors has been suggested to contribute to antigen-induced bronchoconstriction (constriction of the airways in the lungs) in certain asthma patients. In addition to its CysLT1 and CysLT2 antagonist activity, Gemilukast was shown to dose-dependently reduce LTC4-induced bronchoconstriction in asthmatic models, and reduce antigen-induced constriction of isolated human bronchi. A phase II trial with Gemilukast was discontinued in 2018.