Fexofenadine( lat., Fexofenadine) is one of the most popular antihistamines today. The secret of popularity in the absence of most side effects in the treatment and influence on the heart
The scourge of our time is often called allergy. Its forms are extremely diverse, the causative agent can become literally anything, and in the worst cases, the allergy develops without any external influence. Fexofenadine is one of the many medicines that are designed to fight this disaster.
Features of the drug
The active substance of the drug acts as a metabolite of terfendin. When ingested, the substance is completely metabolized to fexofenadine, or, if the complete chemical formula is indicated, in 4- [1-Hydroxy-4- [4-( hydroxydiphenylmethyl) -1-piperidinyl) butyl] -alpha, alpha-dimethylbenzeneacetic acid.
The substance was first synthesized in the laboratories of Sepracor, later the rights to the drug were transferred to Hoechst Marion Roussel. The drug for today is one of the most sold antihistamines.
Dosage Forms
Fexofenadine hydrochloride is a crystalline powder, white or colorless. The drug comes in two different forms:
- tablets - the most convenient form for adults. The dose of the substance in the tablets can be 120 or 180 mg. The blister contains 10 tablets. Generics, including the substance in the composition, may have a different dosage - 30, 60, 120 and 180 mg;
- suspension - on the Russian market is almost not found, is designed primarily for children. Produced in the form of vials in a volume of 30 and 300 ml, contains 6 mg of fexofenadine per ml of the suspension.
Composition of fexofenadine
Composition of the drug - in tablet form, is:
- fexofenadine - 120 or 180 mg;
- titanium dioxide and silicon oxide;
- magnesium stearate;
- lactose monohydrate;
- cellulose and talc.
Except for fexofenadine, the rest of the substances are ancillary and do not affect the effect of the medication. The composition should pay attention to patients suffering from intolerance to lactose: with high sensitivity, even small amounts of it can cause an undesirable reaction.
Prices
The drug is one of the most popular antihistamines, just due to the absence of effects on the heart. Trademarks that can be found on the Russian market are telfast, fexofast, feksadin. The cost of it is determined by the dosage of the active substance, the packaging and the producing country.
- Telfast - a blister with 10 tablets at a dosage of 120 mg costs from 359 to 410 rubles. At a dosage of 180 mg - from 579 to 659 r.
- Fexofast - with a dosage of 120 mg blister costs from 195 r. Tablets in 180 mg - from 244 to 349 rubles.
- Fexadine - 10 pills containing 120 mg of fexofenadine are from 245 to 278 p. At a dosage of 180 mg - from 383 to 530 p.
The effect of the drug on the course of an allergy is based on the blocking of peripheral H1-histamine receptors. Thus, the cell membrane is stabilized and there is no release of histamine, which, in fact, forms an allergic reaction. Pharmacodynamics
The drug is characterized by the following effects on the human body:
- for 1 hour after taking the pill develops an antihistamine effect - suppressed sneezing, lacrimation, rhinitis, redness of the eyes. The maximum effect is achieved after 2-3 hours after administration;
- besides this substance can inhibit bronchospasm if the manifestation of an allergy is related to the state of the airways;
- is maintained for 12 hours;
- , fexofenadine does not become addictive; in the study of this kind, effects were not detected;
- does not have a mutagenic, carcinogenic or tetragonal effect;
- for the work of potassium and calcium channels the drug does not affect, it is allowed to use in renal ailments;
- medication does not affect the activity of the heart and the value of blood pressure.
Pharmacokinetics
An allergic reaction is associated with a malfunction in the immune system. A certain tissue site is suddenly perceived as alien and is attacked by a large number of leukocytes. The latter and cause inflammation of the body or tissue, which manifest as symptoms of inflammation - sneezing, itching, irritation.
- Fexofenadine influences basal expression of adhesion molecules, that is, does not allow leukocytes to move into the presumed focus of inflammation. Also, the substance suppresses the release of interleukin-6, interleukin-8 and adhesion molecules, which cause seasonal allergic rhinitis.
- The drug is fully absorbed by the intestine. The maximum concentration in the blood is observed after 2.5 hours after use. In single use, the substance content in the plasma is 209 ng / ml, the equilibrium level during treatment reaches 286 ng / ml. The maximum concentration possible at a high dose is 494 ng / ml.
- The elimination half-life of the substance is 14, 4 hours, the clearance is 3.4 ml / min / kg.
- Fexofenadine itself is metabolized only by 5% and is excreted unchanged - 11% with urine and 80% with feces.
- Even with hemodialysis and during acute renal failure, the pharmacokinetics of the drug is practically unchanged, only slightly longer is the half-life, which indicates its complete safety. With liver diseases, the parameters also remain unchanged.
- It is noted that fexofenadine is excreted in breast milk, so use during the period of feeding is undesirable.
Indications
The drug is used to eliminate allergy symptoms. On the individual sensitivity to any irritant factor, and even more so on autoimmune disorders, the substance has no effect.
Symptoms prescribed fexofenadine include:
- seasonal and year-round rhinitis;
- is a characteristic red rash in various parts of the body, which is identified as urticaria, including giant urticaria, dermographic, cold, aquatic, Edema Quincke,
- itching, localized skin itching, skin irritation, lacrimation;
- swelling of the mucosa;
- rubromycosis;
- nodular scabies;
- caterpillar dermatitis;
- chronic ailments of an allergic origin.
Instruction for use
The standard package of the medicine includes an instruction detailing the principle of the action of the substance, methods of application, contraindications and so on.
Adults
Patients after 12 years of age the drug is prescribed depending on the diagnosis:
- with pollinosis or rhinitis - 120 mg 1 time per knock;
- for urticaria - 180 mg once a day.
If the patient's work is associated with high nervous tension and requires increased concentration, the dose is selected individually so that the drug does not affect work capacity.
The drug is consumed regardless of the meal. The tablet is washed down with water - juices and compotes are forbidden. Suspension before use should be shaken.
For children and newborns
Patients from 6 to 11 years of age are given the following doses:
- with rhinitis and urticaria - 30 mg twice a day;
- for diseases on the background of chronic renal failure - 30 mg 1 time per day.
Children under 6 years of age can not be prescribed.
In pregnancy and lactation
The dose in pregnancy and during the period of feeding is selected individually. The drug is prescribed in those cases when the benefit from its action is objectively higher than the potential risk for the child.
Contraindications
Due to the high safety of the substance and the ease of withdrawal, restrictions for its use are minimal:
- age to 6 years;
- individual sensitivity to fexofenadine;
- pregnancy, lactation, if on objective data, the substance can adversely affect the child.
Side effects of
In some cases, the action of an antihistamine drug can cause the following side effects:
- insomnia or, conversely, drowsiness, dizziness, fatigue possible;
- nausea before vomiting, constipation, indigestion. In these cases, the drug should be discontinued;
- may cause chest and throat pain, increase the sensitivity of the upper respiratory tract to infections and colds;
- is rare, but anemia may occur;
- may have back and lower back pain.
No overdose data, because the substance does not accumulate. If you use a very high dose, you may experience dizziness, drowsiness, in these cases enterosorbents and light laxatives are shown so that the drug can be withdrawn as soon as possible.
Specific instructions
- Although fexofenadine does not affect the functioning of the kidney and liver, patients with similar diseases should be treated with caution. Reception should be under observation, at least for the first time, and with the appearance of side effects the drug is canceled.
- When pregnant fexofenadine is prescribed, it is also necessary to take into account both potential benefits and potential harm and correctly correlate them.
- Be sure to drink the medicine with water, as the drug causes dryness of the mucous membranes.
Interaction with other medications
If the drug is prescribed against the backdrop of ongoing treatment, its compatibility with other medicines must be considered.
- The concentration of fexofenadine in plasma increases when used together with erythromycin and ketoconazole. Usually this does not cause side effects. But if any, the dose of the drug is reduced.
- The substance is perfectly compatible with omeprazole and its analogs.
- The absorption and antihistaminic effect of the substance decreases with the intake of preparations including magnesium and aluminum hydroxides - antacids, for example. In this case, there should be at least 2 hours between preparations.
- Alcohol does not affect the bioavailability of fexofenadine, and the latter does not increase intoxication.
Reviews
- Chronic urticaria or chronic allergic rhinitis require an individual approach. The doctor, prescribing the drug, takes into account its compatibility with other medicines, and also chooses an individual diet. The latter is especially important in cases when an allergen is a food product.
- It is important to limit contact with household chemicals, as the latter is in any case an irritating factor.
Fexofenadine is a method of getting rid of allergy symptoms - itching, rashes, irritation, tearing. The reason for the allergy is different, so the drug is rarely prescribed by itself, but only accompanied by a medicine designed to eliminate the cause of the reaction. - Patients report a rapid resolution of symptoms, so, itching and tearing can disappear after just 2 medications. The rash passes somewhat later. If the course also includes sorbents, it is necessary to observe the time interval between the medications - at least 2 hours.
Analogs
For preparations containing fexofenadine as an active ingredient, include:
- telphase - in the US and Europe known as allegro, production - France;
- fexofast - production India;
- fexadine - manufactured in India;
- feksofen-sanovel - production Turkey;
- Gyfast;
- fexofenadine hydrochloride.
The effect of the drug is the same, only the dose of the substance in the tablets differs. There are a number of other antihistamines, but their effect may differ markedly.
Fexofenadine is an effective antihistamine, which, in addition, is highly safe. The medicine does not affect the work of the heart, kidney and liver, which allows taking it in the treatment of a wider range of patients.
Fexofenadine is a method of getting rid of allergy symptoms - itching, rashes, irritation, tearing. The reason for the allergy is different, so the drug is rarely prescribed by itself, but only accompanied by a medicine designed to eliminate the cause of the reaction.