Description
Ondansetron-Altpharm Pharmacodynamics
An antiemetic drug of central action. Selective serotonin 5NT3 receptor antagonist.
Drugs for cytostatic chemotherapy and radiotherapy may cause increase in serotonin level, which by activation of vagal afferent fibres containing serotonin 5NT3 receptors, causes gag reflex. Ondansetron inhibits the onset of the gag reflex by blockade of serotonin 5NT3-receptors at the neuronal level of both the central and peripheral nervous system. Apparently, prevention and treatment of postoperative and caused by cytostatic chemotherapy and radiotherapy nausea and vomiting are based on this mechanism of action.
Indications
Prevention and relief of nausea and vomiting caused by cytostatic chemotherapy and radiotherapy.
Contraindications
– pregnancy;
– Lactation (breast-feeding);
– childhood;
– Hypersensitivity to ondansetron or any other component of the preparation.
Directions for use and dosages
- The drug is used rectally. To take the suppository out of the cellular package, break off one cell with a suppository along the notch and pull the edges of the tape apart, pulling them in different directions. The suppository is inserted into the anus with the pointed end, as deep as possible. For more comfortable insertion of the suppository is recommended to bend over, squat or lie on your side with your legs tucked.
- The choice of dosing regimen is determined by the severity of the emetogenic effect of antitumor therapy.
- At moderate emetogenic chemotherapy or radiotherapy, 16 mg ondansetron is prescribed 1-2 hours before the beginning of basic therapy.
- For highly emetogenic chemotherapy, the recommended dose is 16 mg concomitantly with 20 mg of dexamethasone administered intravenously 1-2 h before the start of chemotherapy.
- To prevent late or prolonged vomiting occurring 24 hours after the end of chemotherapy or radiotherapy, the drug should be continued in a dose of 16 mg once/for 5 days.
- The drug is not recommended for use in children.
- No dose changes are required in elderly patients.
- In patients with renal failure no changes in dose, frequency of administration or route of administration are required.
- For patients with impaired liver function, the daily dose of ondansetron should not exceed 8 mg.
- Patients with slow sparteine/debrisoquine metabolism do not require adjustment of the daily dose or frequency of ondansetron administration.
