Ondansetron

Ondansetron is a medicament from a subgroup of drugs used for tumors of a malignant nature, as well as substances that are used to correct the negative symptoms that occur with the introduction of anticancer drugs.

Possesses serotoninergichesky and antiemetic activity. The drug blocks the development of gag reflex, providing an antagonistic effect on the endings located in the area of the PNS neurons. The substance does not lead to a weakening of the psychomotor activity of the patient, and also does not cause the development of a sedative effect.

[1], [2], [3],

Indications Ondansetron

It is used for nausea, but also to prevent vomiting, which develops in connection with the performance of radio or chemotherapy procedures for cancer pathologies.

In addition, it may be prescribed to prevent vomiting with nausea after surgical procedures.

[4]

Release form

The release of a component is realized in tablets with a volume of 0.004, and also 0.008 g - 10 such tablets are contained within a pack.

In addition, it can be produced in the form of an injection liquid - inside ampoules with a capacity of 2 or 4 ml (1 ml of liquid contains 0.002 g of the active element); in a box - 5 ampoules.

[5], [6], [7]

Pharmacodynamics

Ondansetron is a substance that has an antagonistic effect on the peripheral (inside the intestine) and the central (inside the brain) endings of serotonin (5-HT3).

The drug prevents and removes nausea with vomiting resulting from the release of serotonin during the procedures of chemo and radiation therapy aimed at eliminating tumors. In the case of reusable leads to a slowdown in the activity of intestinal peristalsis.

The drug has anti-anxiety activity. It does not affect motor coordination and does not lead to impairment of performance.

[8], [9], [10], [11], [12]

Pharmacokinetics

After the intramuscular injection, blood Cmax values are recorded after 10 minutes, and after oral use - after 1.5 hours. Eating food prolongs the absorption period without affecting Cmax.

Bioavailability values are 60%. Synthesis rate with protein is 70-76%; part of the substance passes inside the erythrocytes. The drug is subjected to intensive intrahepatic exchange.

A small part (5%) is excreted unchanged with the urine. The half-life is 3 hours, both for oral use and for parenteral use. This indicator in the elderly is 5 hours.

[13], [14],

Dosing and administration

In oncology, vomiting with nausea that appears after therapeutic procedures is called "emethogenic syndrome."

To prevent the development of this syndrome, 8 mg orally should be taken orally 60 minutes before performing antitumor procedures; Repeated reception of a similar portion is made after 12 hours after therapy.

To prevent late vomiting, which appears after a day, 2-fold intake of 8 mg of medication per day continues for 6 days after the completion of anticancer measures. To obtain a more intense effect, the portion can be increased to 24 mg, also prescribing dexamethasone (12 mg) together with Ondansetron (120 mg) 120 minutes before the chemotherapy procedure.

It is also possible to administer the drug in the form of an injection liquid. In case of moderate intensity of the emetogenic syndrome, 8 mg of the drug is used (intramuscularly or intravenously injected) before each therapeutic procedure. If the syndrome has severe severity, it is necessary to inject 8 mg of intravenous drug intravenously before the chemotherapy session, and then in the same portion and in the same way, with 3-4-hour intervals.

To prevent vomiting with nausea after surgical procedures, together with the administered general anesthesia, 4 mg of Ondansetron is used intravenously or intramuscularly. In case of vomiting, 4 mg should be administered 3 times a day.

For children, to prevent postoperative vomiting, administration of 0.1 mg / kg of the drug is required intravenously, at low speed, after anesthesia.

Children older than 2 years old are given intravenous doses of 5 mg / m ^{2 of} medication before performing the chemotherapy session; after 12 hours, oral administration of 4 mg of the drug is prescribed. Next, the substance is used 2 times a day in a 4 mg dose for 5 days.

[17], [18]

Use Ondansetron during pregnancy

It is forbidden to appoint Ondansetron during pregnancy.

Contraindications

The main contraindications:

• breast-feeding;
• severe intolerance to the drug;
• combined use with apomorphine;
• prolongation syndrome QT (having a congenital character).

[15]

Side effects Ondansetron

Among the side effects are:

• a temporary increase in liver enzyme values, diarrhea or constipation and dry oral mucous membranes;
• convulsions, dystonia, headaches, extrapyramidal manifestations and motor disorders;
• eye deviation, transient blindness and visual acuity disorder;
• arrhythmia, bradycardia, pain in the sternum, QT prolongation, reduction in blood pressure, ventricular tachycardia, and ST depression;
• urticaria, angioedema, bronchial spasm, anaphylaxis and laryngism;
• hypokalemia and flushing to the skin of the face;
• burning sensation in the anal area (when using candles), pain in the injection area.

[16]

Overdose

Intoxication occurs potentiation of adverse symptoms.

The medication does not have an antidote; Symptomatic interventions are performed.

[19], [20], [21]

Interactions with other drugs

Very carefully the drug is used together with IMAO, papaverine, carbamazepine and barbiturates, and in addition with erythromycin, griseofulvin, cimetidine and fluoroquinolones. In addition, this list includes rifampicin, metronidazole and diltiazem with lovastatin, macrolides, omeprazole with allopurinol, substances that prolong QT-interval, and ketoconazole.

Combination with tramadol can lead to a decrease in its analgesic activity.

It is forbidden to combine with apomorphine hydrochloride, because it can cause a strong decrease in blood pressure and loss of consciousness.

[22], [23]

Storage conditions

Ondansetron is required to be maintained at temperatures not higher than 25 ° C.

[24], [25]

Shelf life

Ondansetron tablets can be used for a 36-month period from the moment of the sale of the substance, and the shelf life of the injection fluid is 24 months.

[26], [27],

Application for children

The substance is not used for persons under 2 years of age.

[28], [29]

Analogs

Analogues of the drug are the medicines Osetron, Latran, Emetron with Zofran and Ondasol with Ondansetron-Ferein and Ondansetron Teva.

[30], [31], [32]