The effect of montelukast sodium and loratadine depends on the treatment of what kind of disease, can not be generalized, because they belong to different kinds of drugs, different indications. 1. montelukast sodium: is a leukotriene receptor antagonist, suitable for long-term treatment of asthma patients, for allergic rhinitis also has a certain effect of relief; adverse reactions are mild, has not been found to be obvious adverse reactions; contraindications for the allergy to this drug, pregnancy, children, the elderly should be used under the guidance of a physician. 2. Loratadine: is the second generation of antihistamine drugs, applicable to a variety of allergic diseases, including allergic rhinitis, allergic conjunctivitis, acute and chronic urticaria; adverse reactions occasionally headache, liver function abnormalities, etc.; contraindications for allergy to this drug, children, pregnancy should be applied under the guidance of a physician. Montelukast sodium and loratadine drug effect has cross but not exactly the same, so should be under the guidance of the doctor to choose, not blindly use drugs, so as not to delay the condition.