Granisetron
When ATH:
A04AA02
Pharmacological action
Antiemetic. Selective serotonin 5HT3-receptors. Relieves vomiting, occurring in the excitation of the parasympathetic nervous system due to the release of serotonin enterochromaffin cells.
Pharmacokinetics
After the on / in the doses 20 ug / kg or 40 mg / kg mean Cmax plasma is respectively 13.7 mg / l 42.8 ug / l.
Plasma protein binding – 65%.
Rapidly metabolized by demethylation and oxidation.
T1/2 is 3.1-5.9 no. In cancer patients T1/2 increases to 10-12 no. Excreted in the urine and feces mainly as conjugates; 8-15% It found in the urine in an unmodified form.
Testimony
Prevention and treatment of nausea and vomiting associated with chemotherapy cytostatics.
Prevention and treatment of postoperative nausea and vomiting.
Dosage regimen
The adult oral single dose – 1 mg, for in / infusion of a single dose – 3 mg, for in / injection (slowly, no less 30 sec) single dose – 1 mg.
The maximum dose – 9 mg / day.
Children / drip once – 40 mg / kg (but not more 3 mg). Children over 12 s oral single dose – 1 mg.
Multiplicity and duration of use is determined individually.
Side effect
Maybe: transient increase in liver enzymes in the blood, constipation, headache, skin rash.
Contraindications
Hypersensitivity to granisetron.
Hypersensitivity reactions to other selective antagonists of 5-HT3 receptors in the history.
Lactation.
Pregnancy and lactation
Security granisetron treatment in pregnancy has not been established, Therefore, the application is possible only in cases of extreme necessity. If necessary, use during lactation should stop breastfeeding.
Cautions
Use caution when symptoms of intestinal obstruction.
For the treatment and prevention of postoperative nausea and vomiting in children granisetron not applicable.
Drug Interactions
Granisetron does not affect the activity of metabolizing enzymes 3A4 subfamily of cytochrome P450 (responsible for the metabolism of certain narcotic analgesics).
The efficacy of granisetron may be enhanced by intravenous administration of dexamethasone (8-20 mg) before chemotherapy.
In vitro studies have shown, that ketoconazole inhibits metabolism of granisetron, that involves the participation of isoenzyme of cytochrome P450 3A. Specific interaction studies with funds for general anesthesia was conducted, but granisetron well tolerated while the appointment of such drugs and narcotic analgesics.
Upon induction of hepatic enzymes phenobarbital, an increase in clearance of granisetron (at / in the introduction) about a quarter.
There was no interaction with concomitant administration with benzodiazepines, trankvilizatorami, anti-ulcer drugs and other cytotoxic drugs, induce vomiting.
