About dimethindene maleatea first generation histamine h1 antagonist, antipruritic, anti-allergic agent.mechanism of action of dimethindene maleatethis drug blocks the receptors of histamine (h1 receptors) centrally and peripherally. this results the inhibition of activation and allergic symptoms produced by histamines. the drug also have some antimuscarinic and serotonic receptor antagonistic actionindications for dimethindene maleate1. allergic dermatitis 2. pruritis 3. ocular allergies 4. urticaria 5. angioedema 6. rhinitis 7. conjunctivitis