The Use And Synthesis Method Of Loratadine
Antiallergic drugs
Loratadine is a commonly used antiallergic drug, belonging to the second generation of long-acting tricyclic antihistamines. It has a fast onset, strong effect, and does not contain hormones. The body absorbs and metabolizes more active desloratadine, which competitively inhibits the histamine H1 receptor and suppresses histamine induced hypersensitivity symptoms. It has no significant anticholinergic or central inhibitory effects. Clinically used to alleviate symptoms related to allergic rhinitis, such as sneezing, runny nose, and nasal itching, as well as eye itching and burning sensation. It is also used to alleviate symptoms of chronic urticaria and other allergic skin diseases. Toxicology: Animal experiments have no mutagenic or teratogenic effects. Common adverse reactions include headache, drowsiness, fatigue, dry mouth and blurred vision, decreased or elevated blood pressure, palpitations, syncope, hyperkinesia, liver function changes, jaundice, hepatitis, liver necrosis, hair loss, seizures, breast enlargement, erythema multiforme, and systemic hypersensitivity reactions. Drug interactions: Drugs that inhibit the function of liver drug metabolism enzymes can slow down the metabolism of this product, such as itraconazole and ketoconazole. Taking 400mg of ketoconazole daily can increase the plasma concentration of this product and its active metabolite, decarboxyethyl loratadine, but no electrocardiogram changes were observed. Combined with macrolide antibiotics, cimetidine, theophylline, and other drugs can also inhibit the metabolism of loratadine.
Production method
Dissolve 4- (8-chloro-5,6-diamino-11H-benzocycloheptanopyridin-11 subunit) -1-methylpiperidine in toluene, add ethyl chloroformate dropwise, complete the reaction, add water, separate the benzene layer, wash with water, dry, and concentrate under reduced pressure to obtain an oily substance, soak with ether, and recrystallize to obtain loratadine.
Purpose
Anti histamine drugs have high selectivity for peripheral nerve H1 receptors, strong effects, and long duration. It is a long-acting tricyclic antihistamine that competitively inhibits the histamine H1 receptor and inhibits allergic symptoms caused by histamine. No significant anticholinergic or central inhibitory effects. Used to alleviate symptoms related to allergic rhinitis and alleviate symptoms of chronic urticaria and other allergic skin diseases.
Usage and dosage
Due to different dosage forms and specifications, please carefully read the drug manual or follow medical advice for usage and dosage.
Adverse reactions
(1) Less. Occasional dry mouth, headache, etc.
(2) Occasional liver dysfunction, jaundice, hepatitis, and liver necrosis should be reduced in patients with impaired liver function.
(3) Rare erythema multiforme and systemic allergic reactions.
Contraindication
Prohibited for those who are allergic to this product. Not recommended for children under 2 years old. Pregnant and lactating women should use it with caution.
Matters needing attention
1. Patients with severe liver or kidney function damage, children under 2 years old, pregnant women, and lactating women should use it with caution.
2. If loratadine is continuously used for more than one month, the drug variety should be changed to prevent drug resistance.
3. Drinkers and those who frequently take antipsychotic drugs should strengthen their observation for any worsening of drowsiness or other central inhibitory effects during the initial use of loratadine, and pay attention to adjusting the dosage, or stop drinking alcohol and stopping diazepam drugs during the medication period.
4. Approximately 48 hours before conducting a drug skin test, loratadine should be discontinued as antihistamines can prevent or reduce positive skin reactions to the antigen used.
