Allegra instruction for use
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Clinical and pharmacological group
The blocker of histamine H1 receptors. Anti-allergic drug
Form of release, composition and packaging
Tablets covered with a filmy coating of light pink color, oblong, biconcave, engraved "012" on one side and stylized "e" on the other.
1 tab. fexofenadine hydrochloride 120 mg
Excipients: croscarmellose sodium - 24 mg, pregelatinized starch - 120 mg, microcrystalline cellulose - 133 mg, magnesium stearate - 3 mg.
The composition of the membrane: hypromellose E-15 - 2.84 mg, hypromellose E-5 - 1.89 mg, povidone - 0.51 mg, titanium dioxide (E171) - 2.025 mg, silicon colloidal dioxide - 0.73 mg, macrogene 400 - 3.94 mg, iron oxide dye pink mixture) (iron oxide red (E172), titanium dioxide (E171)) - 0.025 mg, iron dye oxide (yellow mixture) (iron oxide yellow (E172), titanium dioxide (E171)) 0.040 mg.
10 pieces. - blisters (1) - packs of cardboard.
pharmachologic effect
The blocker of histamine H1 receptors. Fexofenadine (a pharmacologically active metabolite of terfenadine) is an antihistamine with selective antagonistic activity to histamine H1 receptors without anticholinergic and alpha-adrenergic blocking action. In addition, fexofenadine does not have a sedative effect and other effects from the CNS.
In studies in humans, the histamine-induced blistering and hyperemia of anti-histamine action of fexofenadine ingested 1 or 2 times a day appears after 1 hour, reaches a maximum after 6 hours, and lasts for 24 hours after its administration. Even after 28 days of fexofenadine, there was no development of tolerance to the drug. With a single administration of fexofenadine, a dose-related increase in antihistamine effect is observed with an increase in the dose from 10 mg to 130 mg. When using the same model of antihistamine action, it was found that a dose of at least 130 mg was necessary for a constant action for 24 hours. Maximum suppression of blistering and hyperemia of the skin is more than 80%.
In patients with seasonal allergic rhinitis who received up to 240 mg of fexofenadine 2 times / day for 2 weeks, the duration of the QTc interval (QT corrected) did not differ from that with placebo.
Also, there were no changes in QTc when fexofenadine was administered to healthy volunteers at 60 mg 2 times / day for 6 months, 400 mg 2 times / day for 6.5 days and 240 mg / day for 1 year compared to QTc duration with placebo .
Even with a plasma concentration 32 times higher than the therapeutic concentration in humans, fexofenadine had no effect on the potassium channels of delayed rectification in the human heart.
Pharmacokinetics
Suction and distribution
Fexofenadine is rapidly absorbed after ingestion, Tmax is approximately 1-3 hours. The mean Cmax at 120 mg / day is approximately 289 ng / ml, and at intake of 180 mg / day - approximately 494 ng / ml.
Pharmacokinetics with a single and course of fexofenadine (inside to 120 mg 2 times / day) is linear. At a dose of 240 mg 2 times / day, an increase in the proportion of AUC slightly increased (8.8%), this indicates that the pharmacokinetics of fexofenadine is practically linear in the dosage range of 40 to 240 mg per day.
The binding of fexofenadine to plasma proteins is 60-70%.
Metabolism
Fexofenadine is slightly metabolized in the liver and outside it, which is confirmed by the fact that it is the only substance found in significant quantities in urine and feces of humans and animals.
Excretion
With the course of taking the drug, the curve of excretion of fexofenadine from the plasma decreases bi-exponentially, and the final T1 / 2 is 11-15 hours.
According to the data available to date, most of the dose taken in unchanged form is excreted in bile, and up to 10% in urine.
Indications
- seasonal allergic rhinitis (to reduce symptoms) - tablets 120 mg;
- chronic idiopathic urticaria (to reduce symptoms) - 180 mg tablets.
Contraindications
- hypersensitivity to any of the components of the drug;
- Pregnancy;
- lactation period;
- Children under 12 years old.
Carefully:
- in patients with chronic renal and hepatic insufficiency, as well as in elderly patients (lack of clinical experience in this category of patients);
- in patients with cardiovascular diseases, incl. in the anamnesis (antihistamines can cause palpitation and tachycardia).
Dosage
The drug is intended for oral administration.
The recommended dose of fexofenadine for seasonal allergic rhinitis for adults and children 12 years and older is 120 mg 1 time / day before meals.
The recommended dose of fexofenadine for chronic urticaria for adults and children 12 years and older is 180 mg 1 time / day before meals.
Studies in special risk groups (elderly patients, patients with renal and hepatic insufficiency) showed that they do not require correction of the dosing regimen.
Side effects
In placebo-controlled clinical trials, headache (7.3%), drowsiness (2.3%), dizziness (1.5%) and nausea (1.5%) were seen most frequently (?1% - <10%). When fexofenadine was taken, the frequency of the above adverse effects was similar to that of placebo.
In placebo-controlled studies with a frequency of less than 1% (the same with fexofenadine and placebo) and with postmarketing use, weakness, insomnia, nervousness and sleep disturbances, or unusual dreams (paronies) such as nightmares; tachycardia, palpitations; diarrhea.
In rare cases (?0.01% - <0.1%): exanthema, urticaria, pruritus and other hypersensitivity reactions such as Quincke's edema, difficulty breathing, shortness of breath, skin flushing, systemic anaphylactic reactions.
Overdose
Symptoms: dizziness, drowsiness and dry mouth. Healthy volunteers took single doses up to 800 mg and dose doses up to 690 mg 2 times / day for 1 month or 240 mg 2 times / day for 1 year without any significant undesirable effects compared with placebo. The maximum tolerated dose for fexofenadine is not established.
Treatment: in case of an overdose it is recommended to perform gastric lavage, taking activated charcoal, symptomatic and supportive therapy if necessary. Hemodialysis is ineffective.
Drug Interactions
With the combined use of fexofenadine with erythromycin or ketoconazole, the concentration of fexofenadine in plasma increases by 2-3 times, but this is not accompanied by a significant lengthening of the QTc interval. There were no significant differences in the incidence of adverse effects in the use of these drugs as monotherapy and as part of combination therapy. Animal studies have shown that the above increase in plasma concentrations of fexofenadine is probably associated with an improvement in fexofenadine absorption and a decrease in its biliary excretion or secretion in the lumen of the gastrointestinal tract.
There is no interaction between fexofenadine and omeprazole.
Does not interact with drugs metabolized in the liver.
Taking antacids containing aluminum or magnesium 15 minutes before taking fexofenadine leads to a decrease in the bioavailability of the latter as a result of, apparently, binding in the digestive tract.
special instructions
It is recommended that the time interval between taking fexofenadine and antacids containing aluminum or magnesium hydroxide is at least 2 hours.
Use in Pediatrics
For use in children from 6 to 11 years, 30 mg tablets are produced.
Impact on the ability to drive vehicles and manage mechanisms
When taking the drug, it is possible to perform work that requires a high concentration of attention and speed of psychomotor reactions (with the exception of patients who have an unconventional reaction). Therefore, it is recommended to check the individual response to fexofenadine before taking these activities.
Pregnancy and lactemia
There is insufficient data on the use of fexofenadine in pregnant women. Limited animal studies showed no evidence of adverse effects on pregnancy, intrauterine development, childbirth and postnatal development. Fexofenadine should not be used during pregnancy.
Data on the content of fexofenadine in breast milk when it is taken by women during breastfeeding are absent. However, it is shown that terfenadine is excreted in breast milk in women. Therefore, the use of fexofenadine during breastfeeding is not recommended.
Application in childhood
Contraindicated in children under 12 years.
In case of violations of kidney function
Use with caution in chronic kidney failure. No dosage adjustment is required.
With violations of liver function
Use with caution in chronic liver failure. No dosage adjustment is required.
Application in old age
Use of the drug with caution for elderly patients (lack of clinical experience in this category of patients). No dosage adjustment is required.
Terms and conditions of storage
The drug should be stored out of reach of children at a temperature of no higher than 25 ° C. Shelf life - 3 years.