Pharmacist's Antidote | Allergies are prevalent in summer, how to choose medicine scientifically?

In the hot summer, air conditioners are frequently used and various mosquitoes are active, which leads to the spread of allergens and easily causes various allergic diseases. For allergies, anti-allergic drugs are usually used to control symptoms. However, there are so many drugs for treating allergies. How to choose a scientific one?

Allergic reaction is an abnormal immune response of the body to allergens. Histamine is the main mediator of allergic reaction. Oral anti-allergic drugs mainly refer to antihistamines, which can be roughly divided into three generations: the first generation of antihistamines commonly used are chlorpheniramine maleate (chlorpheniramine), diphenhydramine hydrochloride, etc., which are mainly suitable for itchy allergic reaction diseases, such as urticaria, allergic dermatitis, eczema, pruritus, etc.
This type of drug has obvious adverse reactions on the central nervous system. After taking it, symptoms such as drowsiness, fatigue and slow reaction will occur. Drivers and workers who need to concentrate highly should use it with caution. At the same time, this type of drug also has anticholinergic effects and should be used with caution in patients with prostatic hypertrophy, glaucoma, liver and kidney dysfunction and the elderly. In addition, because its safety for use in children is unclear, it is not suitable for children under 6 years old. Commonly used second-generation antihistamines include loratadine, cetirizine, etc., which are mainly suitable for chronic and seasonal allergic rhinitis, chronic urticaria, etc.
Compared with the first generation, the second generation of antihistamines has greatly reduced adverse reactions to the central nervous system, almost no drowsiness, and the safety data for children is more comprehensive and specific. At present, due to its advantages, the second generation of antihistamines are much more widely used than the first generation of drugs. However, in some specific cases, first generation drugs can still be selected. For example, patients with skin allergies can take chlorpheniramine maleate before bedtime when severe itching affects sleep. The adverse reaction of drowsiness is just used to help sleep. The third generation of antihistamines are metabolites of the second generation of drugs, mainly including fexofenadine, desloratadine, etc., which are mainly suitable for allergic rhinitis, allergic asthma, various allergic skin diseases, etc. This type of drug is safer than the second generation of drugs and can be used for pregnant and lactating women and children.
Because drug resistance may develop, it is not advisable to take the same anti-allergic drug continuously for more than 1 month. If the symptoms do not improve, do not increase the drug dosage without authorization, and take anti-allergic treatment under the professional guidance of a doctor.