What Is Fexofenadine?
Fexofenadine is a tablet. This product is suitable for alleviating the symptoms associated with seasonal allergic rhinitis in adults and children 12 years and older. Such as sneezing, runny nose, itchy nose, epicondylitis, throat, itchy, wet, reddened eyes. It can also reduce the symptoms caused by seasonal allergic rhinitis and chronic idiopathic urticaria.
Fexofenadine
- Fexofenadine is a tablet. This product is suitable for alleviating the symptoms associated with seasonal allergic rhinitis in adults and children 12 years and older. Like sneezing, runny nose,
- Common name: Fexofenadine hydrochloride tablets
- Commodity name: Atlas (RALTIVA)
- English name: Fexofenadine Hydrochloride Tablets
- Phonetic script: Hansuan Feisuofeinading Pian
- The main ingredients of this product are: fexofenadine hydrochloride. Chemical name: Hydrochloride of , dimethyl-4- [1-hydroxy-4- [4- (hydroxydiphenylmethyl) -1-pyridine] butyl] -phenylacetic acid.
- Molecular weight: 538.13
- [Traits]
- This product is a light red oval film-coated tablet, wet white to off-white after removing the coating.
- Pharmacological action
- This product is a third-generation H1 receptor antagonist, a carboxylated metabolite of terfenadine, which selectively blocks the H1 receptor and has a good antihistamine effect, but no anti-serotonin , Anti-choline and anti-adrenalin effects. Animal studies have shown that fexofenadine can selectively inhibit antigen-induced bronchospasm in sensitized guinea pigs; it can inhibit the release of histamine from peritoneal mast cells in rats; it does not have the physiological effects of parasympathetic society or alpha * adrenaline Receptor blocking effect; and fexofenadine does not have sedative effects and other central nervous system effects. Therefore, it cannot pass through the blood-brain barrier, does not block the potassium channels of animal cardiomyocytes; does not affect the potential repolarization of the patient's cardiac function, does not extend the QT interval, and produces cardiotoxicity.
- This product is absorbed quickly after oral administration, and the blood concentration reaches a peak about 1 ~ 3 hours after a single oral dose. After oral administration of 60mg, 120mg and 180mg, the peak serum drug concentrations Cmax are 142ng / ml, 427ng / ml and 494ng / ml . Fexofenadine protein binding rate is about 60 ~ 70%. Fexofenadine cannot cross the blood-brain barrier and is hardly metabolized. Only 5% of the drug is metabolized by the liver into ketoacid metabolites. Most of the remaining drugs are excreted by urine and feces in prototypes, of which about 11% % Is excreted by urine, 80% of the drug is excreted by feces, and the elimination half-life of fexofenadine is about 14.4 hours.
- This product is suitable for reducing the symptoms caused by seasonal allergic rhinitis and chronic idiopathic urticaria.
- This product is taken orally for adults and children over 12 years of age and the elderly: the recommended dose for seasonal allergic rhinitis is 120 mg (2 tablets) once a day, and the recommended dose for chronic urticaria is 180 mg (3 tablets) once a day. The first dose of patients with low renal function is 60mg (1 tablet) once a day. The elderly and patients with liver damage do not need to adjust the dose.
- Children 6 to 11 years of age: The recommended dose for seasonal allergic rhinitis and chronic idiopathic urticaria is 30 mg (tablets) once a day, and the first dose for patients with renal insufficiency is 30 mg (half tablet) once a day.
- The most commonly reported adverse reactions to fexofenadine in controlled clinical studies were headache, lethargy, nausea, dizziness, and fatigue. These adverse effects were similar to those observed in the placebo group. The incidence of drowsiness and fatigue was 1.3%, the incidence of nausea and indigestion was 1.6%, and the incidence of headache and leukocytosis was 1.5%. There have been no reports of severe cardiotoxicity caused by fexofenadine.
- Hepatic dysfunction does not need to be reduced, and patients with renal dysfunction need to be halved.
- [Contraindications] Those who are allergic to this product are prohibited.
- [Medication for pregnant and lactating women]
- At present, there is no safety test data for pregnant women to use this product, so pregnant women are generally not suitable to use this product. If the disease is necessary, they should be used with caution after weighing the advantages and disadvantages.
- There are currently no safety information on the use of this product by lactating women, but many drugs are excreted from milk. Some young children may have some adverse reactions after taking the drug-containing milk. Therefore, if the disease is necessary for lactating women, they should weigh the pros and cons and use it with caution.
- [Child medication]
- The safety and effectiveness of this product for children under 6 years have not been established.
- [Medication for elderly patients]
- In a placebo-controlled clinical trial, 42 elderly patients aged 60 to 68 years were given 20 mg to 240 mg of fexofenadine 2 times a day for 2 weeks. The adverse reactions were similar to those of patients under 60 years old. Produces similarities. No adjustment is needed for elderly patients.
- Fexofenadine does not undergo biotransformation by the liver, so it does not interact with drugs that rely on liver metabolism.
- (1) 15 minutes before taking fexofenadine hydrochloride, the use of antacids containing aluminum or magnesium hydride gel will reduce the bioavailability of fexofenadine, so the time of administration should be 2 hours apart .
- (2) Studies show that it is safe and effective to give healthy volunteers fexofenadine 120 mg twice daily combined with erythromycin 500 mg three times a day or ketoconazole 400 mg once a day. When erythromycin or ketoconazole is used in combination, the plasma concentration of fexofenadine will be increased by two times, but the incidence of adverse reactions will not be increased. For example, the QT interval will be prolonged. And ketoconazole had no effect on pharmacokinetics.
- (3) No interaction was observed between fexofenadine and omeprazole.