ONDANSETRON-ALTFARM

General characteristics. Structure:

Deysveshchestvo: ондансетрон hydrochloride of 4 mg, 8 mg or 16 mg
excipients: витепсол N 15

Description. Suppositories of color, white or white with a creamy shade, a torpedo-shaped form without visible impregnations on longitudinal section.

Pharmacological properties:

Pharmacodynamics. Ondansetron is the selection antagonist of receptors 5HT3 (serotonin). Medicines for cytostatic chemotherapy and radiotheraphy can cause increase in level of serotonin which by activation of the vagal afferent fibers containing receptors 5-HT3 causes an emetic reflex. Ondansetron slows down emergence of an emetic reflex by blockade of receptors 5-HT3 at the level of neurons of both the central, and peripheral nervous system. Apparently, the prevention and treatment postoperative and caused cytostatic himio-and radio - therapy of vomiting and nausea is based on this mechanism of action.

Pharmacokinetics. After rectal administration ондансетрон is defined in plasma in 15-60 min. Concentration of active agent increases linearly, the maximum concentration is reached approximately in 6 h and makes 20-30 ng/ml. Absolute bioavailability at rectal administration makes about 60%. Decrease in concentration in plasma happens to smaller speed, than after intake (owing to the continuing absorption). An elimination half-life – 6 hours. Pharmacokinetic parameters of an ondansetron do not change at its repeated introduction.

Indications to use:

The prevention and elimination of nausea and vomiting, caused by cytostatic chemotherapy and radiotheraphy.

Route of administration and doses:

Drug is used rektalno. To take out suppository from a strip packaging, it is necessary to break off one cell with suppository on a notch and having separated edges of a tape, to pull for them in different directions. Suppository is entered into an anus by the pointed end, whenever possible deeply. For more convenient administration of suppository it is recommended to bend down, sit down on hunkers or to lay down sideways, having drawn in legs. The choice of the mode of dosing is defined by expressiveness of emetogenny action of the carried-out antineoplastic therapy.

At moderate emetogenny chemotherapy or radiotheraphy:
- 16 mg of an ondansetron for 1-2 h prior to performing the main therapy.

At vysokoemetogenny chemotherapy:
The recommended dose makes 16 mg along with intravenous administration of 20 mg of dexamethasone in 1-2 hours prior to carrying out chemotherapy.
For prevention of late or long vomiting of the chemotherapy arising in 24 hours after the termination or radiotheraphy, it is necessary to continue administration of drug in a dose of 16 mg within 5 days once a day.

Children.
Ondansetron in suppositories is not recommended for use for children.

Patients of advanced age.
Change of a dosage is not required.

Patients with a renal failure.
Special changes of a dosage, frequency of reception or route of administration are not required.

Patients with abnormal liver functions.
The daily dose of an ondansetron for this category of patients should not exceed 8 mg a day.

Patients with slow metabolism of sparteine / дебрисохина.
Correction of a daily dose or frequency of reception of an ondansetron is not required.

Features of use:

The patients who had earlier allergic reactions to other selection blockers of 5-HT3-receptors have the increased risk of their development against the background of an ondansetron.
Ondansetron can slow down motility of a large intestine in this connection, its appointment as the patient with signs of impassability of intestines demands special observation.

Side effects:

Allergic reactions: small tortoiseshell, bronchospasm, laryngospasm, Quincke's disease, anaphylaxis.

From the alimentary system: a hiccups, dryness in a mouth, a lock or diarrhea, sometimes asymptomatic passing increase in activity of aminotransferases in blood serum.

From cardiovascular system: thorax pains, in some cases with a depression of a segment of ST, arrhythmia, bradycardia, a lowering of arterial pressure.

From a nervous system: headache, dizziness, spontaneous motive frustration and spasms.

Local reactions: a hyperemia, pain, a burning sensation in the field of an anus and a rectum after administration of suppository

Others: "inflow" of blood to face skin, feeling of heat, temporary disturbance of visual acuity, a hypopotassemia, a giperkreatininemiya.

Interaction with other medicines:

There are no data on what ондансетрон induces or inhibits metabolism of other drugs which are often appointed in a combination with it.
Ondansetron is metabolized by several enzymes of system of P450 cytochrome (CYP3A4, CYP2D6 and CYP1A2). Oppression or
decrease of the activity of one of enzymes usually is normal compensated by others in this connection significant decrease in the general
clearance of an ondansetron it is improbable.
Nevertheless, care at combined use is required:
- with the enzymatic inductors P450 (CYP2D6 and CYP3A) (barbiturates, carbamazepine, каризопродол, глютетимид, griseofulvin, a dinitrogene oxide, a papaverine, phenylbutazone, Phenytoinum (it is probable also other hydantoins), rifampicin, Tolbutamidum);
- with inhibitors of P450 enzymes (CYP2D6 and CYP3A) (Allopyrinolum, makrolidny antibiotics, antidepressants – MAO inhibitors, chloramphenicol, Cimetidinum, the oral contraceptives containing estrogen, diltiazem, Disulfiramum, valproic acid, sodium Valproatum, erythromycin, флуконазол, ftorkhinolona, an isoniazid, кетоконазол, ловастатин, metronidazole, омепразол, propranolol, quinidine, quinine, verapamil).
Special researches showed what ондансетрон does not interact with alcohol, temazepam, furosemide, tramadoly and propofoly.

Contraindications:

- Hypersensitivity to an ondansetron or any other component of drug
- Pregnancy and period of feeding by a breast.
- Children's age.

Overdose:

There is a limited experience of overdose of an ondasetron. In most cases symptoms are similar to side reactions at use of drug in the recommended doses.
Treatment: symptomatic and maintenance therapy. The specific antidote for an ondansetron is not known.

Storage conditions:

At a temperature not above 25 °C in the dry place protected from light.
To store in the place, unavailable to children. A period of validity - 2 years. Not to use after the period of validity specified on packaging.

Issue conditions:

According to the recipe

Packaging:

Suppositories rectal on 4 mg, 8 mg and 16 mg. On 5 pieces (suppositories on 4 mg or 8 mg) in a blister strip packaging from a film polyvinyl chloride. One planimetric packaging together with the application instruction in a pack cardboard.
On 1 suppository (16 mg) in a blister strip packaging. One planimetric packaging in a cardboard insert. Two cardboard inserts together with the application instruction in a pack cardboard.