The catkins are flying, the fragrance of flowers is overflowing, the spring is infinitely good, but the nose is itchy. Spring and autumn are the high incidence periods of allergic rhinitis, and antihistamines, represented by them, are the "life-saving drugs" for people who are prone to allergies, and they are therefore on the hot search.
The question is, how can you tell if you have allergic rhinitis or a cold?
| disease | allergic rhinitis | common cold |
| Fever and general malaise | not | Yes |
| Sore throat | not | majority |
| Nasal discharge color | Clear water sample | It is white at first, and then it can change to yellow |
| Nasal itching | More obvious | Mild or moderate |
| Itchy eyes | majority | not |
| Eosinophils | Most are elevated | normal |
| Allergen testing | masculine | feminine |
| Personal and family history | Have a family history of allergies | No special |
Compared with first-generation antihistamines (such as diphenhydramine and chlorpheniramine), second-generation histamine H1 receptor antagonists are highly selective for H1 receptors and have no obvious central inhibition and anticholinergic adverse reactions.
Loratadine only relieves symptoms associated with allergic rhinitis, such as sneezing, runny nose, itchy nose, nasal congestion, and itchy and burning sensation in the eyes, but does not eradicate the allergen.
Although the safety of the drug is high, it should not be taken continuously for more than one month, and patients with abnormal liver and kidney function need to be used with caution.
So, what should I pay attention to when using loratadine?
1. It can be used for the treatment of allergic rhinitis in children
Children aged 2~12 years:
body weight > 30 kg: 10 mg once daily
Body weight ≤ 30 kg: 5 mg once daily
Adults and children over 12 years of age: 10 mg once daily
2. Due to the individual differences in medication, if the symptoms do not improve, do not increase the dose of drugs without authorization, and choose other drugs or treatment methods under the guidance of doctors or pharmacists.
3. Do not drink alcohol while taking antihistamines, otherwise it will increase the burden on the liver and inhibit the central nervous system.
4. It cannot be taken before the skin test, loratadine will prevent or reduce the positive reaction of the skin test, affecting the result.
5. Do not use in combination with antifungal drugs and macrolide antibiotics, these two types of drugs will lead to an increase in the content of loratadine in the blood, which is easy to cause adverse reactions.
What is the difference and connection between loratadine, desloratadine and citrate?
The active product metabolized by the liver is desloratadine, and the antihistamine activity is about 15 times that of loratadine.
It is the disodium hydrogen citrate salt of desloratadine, which has a faster onset of action, higher bioavailability, and a potent and selective antagonistic peripheral H1 receptor effect and anti-inflammatory effect.
Loratadine is metabolized by the liver to desloratadine to work, while desloratadine and desloratadine citrate are not metabolized by the liver and are safer for patients with liver insufficiency.
Reviewers: Li Yongmei, Luo Qian, The Fifth Affiliated Hospital of Guangzhou Medical University
Author: Luo Liang, pharmacist, The Fifth Affiliated Hospital of Guangzhou Medical University