Ondansetron, 2 mg/ml 4 ml 5 pcs

Pharmacotherapeutic group:

A serotonin receptor antagonist anti-emetic

ATX code:

A04AA01

Pharmacological properties

Pharmacodynamics

Ondansetron is a selective 5-NT3 (serotonin) receptor antagonist. Cytostatic chemotherapy drugs and radiotherapy may increase serotonin levels which by activating afferent fibers of the vagus nerve containing 5-HT3 receptors, causes the gag reflex.

Ondansetron selectively blocks serotonin 5-NT3 receptors in neurons of the central (gag center) and peripheral (gastrointestinal tract) nervous system that regulate the gag reflex.

Does not impair coordination of movements, does not cause sedation and decreased performance. Does not change the concentration of prolactin in plasma.

Pharmacokinetics

In intramuscular administration the peak concentration (TSmax) in plasma is reached within 10 minutes. The distribution of ondansetron is the same with oral, intramuscular and intravenous administration. Bioavailability is about 60%. The drug is metabolized in the liver. Binding to plasma proteins is 70-76%. The volume of distribution is 140 l. Period of half-life (T1/2) is 3 hours, in elderly patients it can be up to 5 hours and in case of marked hepatic insufficiency – 15-20 hours.

It is eliminated from systemic blood flow mainly as a result of metabolism in liver, which occurs with the participation of several liver microsomal enzymes (CYP1A2, CYP2D6, CYP3A4). Absence of CYP2D6 isoenzyme has no effect on ondansetron pharmacokinetics. Less than 5% of the administered dose is excreted unchanged in the urine. Pharmacokinetic parameters of ondansetron do not change with its repeated administration. In patients with moderate renal insufficiency (creatinine clearance 15-60 ml/min) both systemic clearance and volume of distribution of ondansetron are reduced, resulting in a small and clinically insignificant increase in T1/2 (up to 5.4 h).

The pharmacokinetics of ondansetron are virtually unchanged in patients with severe renal impairment who are on chronic hemodialysis. In patients with severe hepatic impairment, systemic clearance of ondansetron is sharply reduced, resulting in prolongation of its half-life (up to 15-32 h).

Indications

Active ingredient

Composition

How to take, the dosage

Cytostatic therapy

The choice of dosing regimen is determined by the emetogenicity of the antitumor therapy.

The daily dose for adults is usually 8-32 mg.

The following regimens are recommended.

For moderate emetogenic chemotherapy or radiotherapy: 8 mg intravenously by slow-acting or intramuscularly, immediately before therapy;

For highly emetogenic chemotherapy:

– 8 mg intravenous jet slowly just before the start of chemotherapy, followed by two more intravenous injections of 8 mg, each 2 to 4 hours later;
– A continuous 24-hour infusion of the drug at a dose of 24 mg at a rate of 1 mg/hour;
– 16-32 mg diluted in 50-100 ml of an appropriate infusion solution, as a 15-minute infusion, immediately before the start of chemotherapy.

The efficacy of ondansetron may be increased by a single intravenous injection of a glucocorticoid (e.g., 20 mg dexamethasone) prior to the start of chemotherapy.

In order to prevent delayed vomiting occurring 24 hours after the start of chemotherapy or radiotherapy – both with highly emetogenic therapy and with moderately emetogenic therapy – it is recommended that the drug be continued orally as 8 mg tablets twice daily for 5 days.

Children

In children over 2 years of age, the drug is administered at a dose of 5 mg/m² of body surface area intravenously, immediately before the start of chemotherapy.

Prevention of postoperative nausea and vomiting

Adults are given a single dose of 4 mg intramuscularly or intravenously, slowly at the start of anesthesia.

To relieve nausea and vomiting that occurs, an intramuscular or slow intravenous injection of 4 mg of the drug is recommended. Intramuscularly to the same area of the body, ondansetron may be administered in a dose not to exceed 4 mg!

In children to prevent postoperative nausea and vomiting, ondansetron is used exclusively parenterally in a single dose of 0.1 mg/kg (maximum up to 4 mg) as a slow intravenous injection before, during or after anesthesia.

For the treatment of developed postoperative nausea and vomiting in children, a slow intravenous single dose of the drug of 0.1 mg/kg (up to a maximum of 4 mg) is recommended.

There is not enough experience regarding the prevention and treatment of postoperative nausea and vomiting in children under 2 years of age.

Patients in the elderly

There is no need to change the dosage.Patients with impaired renal function

There is no need to change the usual daily dose and frequency of administration if there is renal impairment.

Patients with impaired hepatic fUNCTION

In moderate to severe hepatic impairment, ondansetron clearance is significantly reduced and plasma elimination half-life is increased, so it is not recommended to prescribe more than 8 mg ondansetron daily in these patients.

The following solutions may be used for dilution of the injection solution:
– 0.9% sodium chloride solution,
– 5% glucose solution,
– Ringer’s solution,
– 0.3% potassium chloride solution and 0.9% sodium chloride solution,
– 0.3% potassium chloride solution and 5% glucose solution.

Interaction

Special Instructions

Contraindications

Side effects

Overdose

Similarities