Uromitexan, 100 mg/ml 4 ml 15 pcs

Pharmacodynamics

Mesna is an antidote of acrolein, a metabolite of anticancer drugs from the group of oxazaphosphorins (ifosfamide, cyclophosphamide), which irritates the bladder mucosa. The protective properties of mesna are due to the interaction with the double bond of the acrolein molecule, which leads to the formation of a stable non-toxic thioether. By reducing the urotoxic effects of oxazaphosphorins, mesna does not weaken their antitumor effects.

Pharmacokinetics

. When administered intravenously, Uromitexan is rapidly oxidized to disulfide and is reduced in the kidneys to a free thiol compound, which binds irreversibly to alkylating derivatives to form non-toxic stable thioethers. Maximum excretion is 2-3 hours after IV injection.

The elimination half-life after an IV dose of 60 mg/kg in the fast phase is 0.17 h, in the slow phase – 1.08 h. Completely excreted by the kidneys within 8 hours, with excretion in the form of SH-mesna during the first 4 hours, 32% of the dose as thiol and 33% as disulfide. When administered orally, absorption occurs in the small intestine.

The average peak concentration of free thiol compounds in the urine is reached after 2-4 hours. Approximately 25 + 10% of the dose taken is detected as free mesna in the urine in the first 4 hours.

In a dose of 2-4 g/sq.m., the half-life of ifosfamide is about 4-8 hours. To maintain adequate levels of mesna in the bladder during elimination of urotoxic metabolites of ifosfamide, an appropriate frequency of administration is necessary.

Indications

Local detoxification of the urotoxic effects of cytostatics – oxazaphosphorin derivatives, including the following cases:

• when oxazaphosphorins are administered in high doses (more than 10 mg/kg);
• in patients at risk
• previous radiation therapy to the pelvic region,<

development of cystitis during previous oxazaphosphorin therapy, history of urinary tract disease.

Active ingredient

Mesna

Composition

1 ampoule of concentrate for preparation of solution for infusion contains:

the active ingredient:

Mesna 400 mg in 4 ml.

auxiliary substances:

sodium edetate,

sodium hydroxide,

water for injection

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How to take, the dosage

Uromitexan is administered intravenously (slowly), the single dose is 20% of the single dose of oxazaphosphorin. The first injection is given simultaneously with the first injection of oxazaphosphorin, the second and third injections – 4 hours and 8 hours after the administration of oxazaphosphorin.

In continuous infusion (24 hours) of ifosfamide or cyclophosphamide, Uromitexan should be given at a dose of 20% of the cytostatic dose at the beginning of the infusion, then at a dose of 100% of the cytostatic dose as a 24-hour infusion, and at the end of cytostatic administration, Uromitexan is continued for another 6-12 hours at the same dose.

Combined intravenous and oral therapy. Uromitexan is administered intravenously (slowly) simultaneously with the first administration of oxazaphosphorin; the single dose is 20% of the single dose of oxazaphosphorin. Two and six hours after intravenous infusion, tablets are taken orally at a dose that is 40% of the oxazaphosphorin dose.

The experience of treating children with Uromitexan tablets shows that more frequent (e.g. every 3 hours) and longer (e.g. up to 6 times) dosing is appropriate.

Interaction

Mesna is compatible with cyclophosphamide and ifosfamide, so it can be administered with them in the same solution, and the antitumor activity of the latter does not change.

Pharmaceutically the drug is incompatible with cisplatin (binding and inactivation of the latter), therefore Mesna should not be mixed in the same solution with cisplatin.

Mesna has no effect on the therapeutic efficacy of adriamycin, carmustine, cisplatin, methotrexate, vincristine and the activity of cardiac glycosides.

Special Instructions

Mesna has a protective effect only on the urinary system and does not eliminate other side effects of cytostatics, so a full range of supportive and symptomatic therapy is necessary when treating with drugs of the oxazaphosphorin group.

False-positive reactions for ketone bodies in urine have been reported during treatment. Reddish-purple staining of urine is possible, which is unstable and disappears immediately when iced acetic acid is added to the urine.

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Contraindications

Hypersensitivity to Mesna or any component of the drug Uromitexan. Pregnancy and lactation period.

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Side effects

Nausea, vomiting, diarrhea (at a single dose of more than 60 mg/kg body weight).

Rarely – phlebitis at the injection site, hematuria, allergic reactions in the skin and mucous membranes.

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