Fexofen

Fexofen is an antihistamine for systemic use.

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Indications Fexofen

It is used to eliminate allergic rhinitis of seasonal origin (0.12 g tablets), as well as the idiopathic form of urticaria of a chronic nature (0.18 g tablets).

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Release form

The release occurs in tablets, 10 pieces inside a blister pack. The pack contains 1 or 2 such packages.

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Pharmacodynamics

Fexofenadine is a histamine (H1) receptor blocker with a specific action pattern. Fexofenadine is a pharmacoactive breakdown product of terfenadine.

When used in therapeutic doses, fexofenadine does not have antidopaminergic, antiadrenergic or anticholinergic effects. Even when used in high doses, the element does not block potassium channels inside myocardiocytes, and in addition, it does not have cardiotoxic properties (arrhythmia or prolongation of QT interval values).

Fexofenadine does not penetrate the blood-brain barrier and therefore cannot interact with H1-terminals within the central nervous system. The drug does not have a sedative effect.

Data from clinical tests conducted in adults with seasonal allergic rhinitis demonstrated that 1 hour after taking doses of the drug of 0.06, 0.12 and 0.18 g, a rapid improvement in the condition was observed, and the therapeutic effect was maintained for the next 24 hours.

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Pharmacokinetics

When administered orally, fexofenadine is rapidly absorbed from the gastrointestinal tract, reaching plasma Cmax values within 1-3 hours. The mean Cmax level following a single 120 mg dose per day was approximately 427 ng/mL. The same value following a single 180 mg dose per day was approximately 494 ng/mL.

A 0.12 g dose of the drug has a half-life (steady-state values) of approximately 14.4 hours. In people over 65 years of age, these values are similar to the younger group. The half-life in children is 18 hours.

Synthesis of the substance with plasma protein is about 60-70%. Approximately 5% of the consumed portion is metabolized.

80% of the drug dosage is excreted in bile, and 11% in urine.

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Dosing and administration

The tablets are taken regardless of food intake, while washing them down with plain water. The standard dosage (for adults and adolescents over 12 years of age) is 0.12 g for the elimination of seasonal allergic rhinitis, and 0.18 g for the elimination of symptoms of idiopathic urticaria (chronic). The drug should be taken once a day (it is recommended to do this in the morning).

The duration of such therapy is selected for each individual by the attending physician, taking into account the course of the pathology. With constant intake of the drug for 28 days, tolerance to fexofenadine did not develop.

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Use Fexofen during pregnancy

There is very little information regarding the use of Fexofen during pregnancy. The few animal tests do not show any direct or indirect effects on the course of pregnancy, embryonic or fetal development, the birth process or the postnatal development of the child.

However, it is still prohibited to prescribe fexofenadine hydrochloride to pregnant women, except in situations where the possible benefit to the woman is more expected than the occurrence of complications in the fetus (if there are vital indications).

Since the element fexofenadine is excreted in breast milk, it is prohibited to use the drug during lactation.

Contraindications

The main contraindication is high sensitivity to medicinal elements.

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Side effects Fexofen

Taking the tablets may cause the appearance of certain side effects:

• lesions associated with the functioning of the nervous system: dizziness, drowsiness and headaches;
• symptoms in the gastrointestinal tract: development of nausea;
• systemic disorders: development of severe fatigue.

During the post-marketing studies, the following adverse reactions were identified:

• immune damage: symptoms of intolerance developing in the form of Quincke's edema, dyspnea, a feeling of constriction in the chest area, and in addition in the form of systemic anaphylaxis and hot flashes;
• mental disorders: increased excitability of the nervous system, insomnia, sleep problems or unusual/nightmarish dreams;
• problems with cardiac function: the appearance of palpitations or tachycardia;
• reactions associated with the gastrointestinal tract: development of diarrhea;
• lesions of subcutaneous tissue and epidermis: itching with rashes and urticaria.

People who have a history of any pathologies affecting the function of the cardiovascular system, or who currently suffer from them, need to take into account that drugs from the antihistamine category can lead to complications such as increased heart rate and tachycardia.

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Overdose

There is evidence of drowsiness, dizziness, and dry mouth in cases of poisoning with Fexofen. In studies involving volunteers, the use of a single dose of up to 0.8 g and a double dose of 0.69 g per day for 1 month or a dose of 0.24 g once per day for 12 months did not cause clinically significant adverse symptoms compared to placebo. It was not possible to establish the maximum permissible size of the tolerable dose of fexofenadine.

In case of intoxication, symptomatic and supportive measures are necessary. The hemodialysis procedure will not be effective.

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Interactions with other drugs

Fexofenadine is not subject to hepatic metabolism, and therefore does not interact with other drugs via this mechanism.

Combination with ketoconazole or erythromycin results in a 2-3-fold increase in plasma fexofenadine levels. The effect on QT interval length is not associated with this change. The incidence of adverse events was not increased compared with the use of either medication alone.

No interaction with the substance omeprazole is observed.

The use of magnesium- and aluminum-containing antacids 15 minutes before taking Fexofen in a 0.18 g dose weakens the properties of fexofenadine, as well as the degree of its synthesis in the gastrointestinal tract. It is necessary to adhere to a 2-hour interval between taking these medications.

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Storage conditions

Fexofen should be kept in a place out of reach of small children. Temperature marks – no higher than 25°C.

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Shelf life

Fexofen is allowed to be used for 3 years from the date of manufacture of the therapeutic drug.

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Use in children

Fexofen is prohibited for use in children under 12 years of age.

Analogues

The following drugs are analogs of the drug: Altiva and Allergo with Fexofast and Fexomax, and in addition Tigofast-120 and Telfast.

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Reviews

Fexofen copes well with allergies, as well as idiopathic urticaria. Reviews indicate that it quickly and effectively relieves itchy rashes, red spots and other symptoms of the above disorders.