Tigofast

Tigofast is an antihistamine drug that is used systemically for the treatment of allergies.

Its active element is the substance fexofenadine (the main metabolic component of the element terfenadine). It is an antihistamine element that affects the body in the form of a selective peripheral antagonist of H-1 endings. [ 1 ]

The drug demonstrates significant antihistamine activity, helping to quickly prevent the occurrence of some allergic reactions. [ 2 ]

Indications Tigofast

It is used in the treatment of diseases of allergic origin. Its therapeutic activity is determined by the dosage of the drug: tablets of 0.12 g are used to eliminate signs of allergic rhinitis, and tablets of 0.18 g are used to treat symptoms of idiopathic urticaria (in the chronic stage).

Release form

The medicine is released in tablets - 10 pieces inside a blister pack; inside a box - 1 or 3 such packs.

Pharmacodynamics

Fexofenadine hydrochloride is an antihistamine non-sedative substance from the subgroup of antagonists of specific H1 endings; this component acts as a metabolic element of terfenadine and has medicinal activity. It stabilizes the walls of labrocytes and prevents the secretion of histamine. In addition, it removes signs of allergy: rhinorrhea, lacrimation, itching with sneezing and redness of the eyes. It does not have a sedative effect.

The antihistamine effect of fexofenadine hydrochloride, administered 1-2 times a day, develops over a period of 1 hour, reaching a maximum level after 6 hours. Its effect lasts for 24 hours. [ 3 ]

No manifestations of intolerance were noted even after 28 days of drug use. The therapeutic effect developed with a single dose of 0.01-0.13 g. A dosage of 0.12 g is sufficient to obtain a 24-hour effect.

Even when plasma values were obtained that were 32 times higher than the therapeutic values, fexofenadine had no effect on the relatively slow cardiac potassium channels.

Fexofenadine hydrochloride, after oral administration of a dose of 5-10 mg/kg, relieves bronchial spasm of an antigenic nature in sensitized animals, and at values exceeding therapeutic (10-100 μmol), leads to the release of histamine from peritoneal labrocytes.

Pharmacokinetics

Fexofenadine hydrochloride is rapidly absorbed when taken orally. It reaches Cmax within 1-3 hours. When using a daily dose of 0.12 g, the average Cmax is ≈ 427 ng/ml; with a daily dose of 0.1 g, it is ≈ 494 ng/ml.

Protein synthesis of fexofenadine is 60-70%. The active element does not cross the BBB.

Fexofenadine is practically not involved in metabolic processes (inside and outside the liver): only fexofenadine is found in large quantities in the feces and urine of humans and animals.

Plasma excretion of fexofenadine is realized with a biexponential decrease and a terminal phase half-life within 11-15 hours with repeated use.

Pharmacokinetic parameters for single and multiple doses are linear (in the case of oral administration of 0.12 g portions 2 times a day).

During the saturation phase, doses of the drug up to 0.24 g twice daily resulted in an increase in the AUC level, which was slightly more than the proportional value (8.8%). From this it can be concluded that at daily doses of 0.04-0.24 g, the pharmacokinetic properties of fexofenadine are almost linear.

The drug is mainly excreted in bile; no more than 10% is excreted unchanged in urine.

Dosing and administration

The medication should be prescribed by the attending physician. In case of elimination of signs of urticaria, which has a chronic form, it is necessary to use 0.18 g of the medication once a day. In the treatment of manifestations of seasonal rhinitis of an allergic nature, 0.12 g of the drug is used once a day.

It is recommended to take the medicine at the same time of day.

The duration of the treatment cycle is selected taking into account the nature and severity of the pathology, as well as the body's response to treatment.

• Application for children

The medication cannot be prescribed to pediatric patients (persons under 12 years of age).

Use Tigofast during pregnancy

Tigofast should not be used during pregnancy because no tests have been performed to confirm its safety in this group of patients.

If you need to take medications while breastfeeding, you must stop breastfeeding for the duration of therapy.

Contraindications

Contraindicated for use in situations where a person has a strong intolerance to the main substance or additional elements.

Side effects Tigofast

Main side effects:

• manifestations affecting the functioning of the nervous system: drowsiness, headaches and dizziness;
• gastrointestinal disorders: diarrhea, nausea and epigastric spasms;
• systemic disorders: feeling of increased fatigue;
• problems with immune function: signs of intolerance, including chest tightness, hot flashes, Quincke's edema, dyspnea, facial flushing and general anaphylactic symptoms;
• mental disorders: increased irritability, insomnia and sleep disorders or strange dreams;
• heart disorders: increased heart rate and tachycardia;
• lesions of the subcutaneous layer and epidermis: rash, itching and urticaria.

Overdose

Poisoning with the drug is observed only occasionally. In case of acute intoxication or accidental overdose, fatigue, drowsiness, xerostomia and dizziness may be observed.

In such situations, symptomatic and supportive measures must be taken – gastric lavage and the use of enterosorbents.

Interactions with other drugs

In case of combined administration of the drug with ketoconazole or erythromycin, the plasma level of Tigofast increases twofold/threefold. This is due to increased absorption in the gastrointestinal tract and decreased biliary elimination. The described changes do not change the QT interval and do not lead to an increase in the number of negative signs (in comparison with the number of side effects when using each of the drugs separately).

When using antacids containing Mg or Al 15 minutes before using the drug, its bioavailability index decreases (due to synthesis processes inside the gastrointestinal tract). It is necessary to observe a 2-hour interval between the administration of these medications.

Storage conditions

Tigofast should be stored in a place closed to small children; temperature indicators – no more than 25oС.

Shelf life

Tigofast can be used within a 24-month period from the date of manufacture of the medicinal product.

Analogues

Analogues of the drug are Claritin, Agistam, Ketotifen and Allergo with Ds-lor, and also Fexofast, Allergostop, Loridin and Astemizole with Eveik. In addition, the list also includes Lorano, Dezorus, Semprex, Eol and Flondian.