Details About Overdose or Poisoning Generic Salt :: Ondansetron
Ondansetron
Drug Pharmacology ::
I. Pharmacology. Ondansetron is a selective serotonin 5-HT3receptor antagonist with powerful antiemetic activity both centrally atthe chemoreceptor trigger zone and peripherally at vagal nerveterminals. The onset is about 30 minutes after an intravenous dose and60–90 minutes after an oral dose. The drug is metabolized extensivelyin the liver. The elimination half-life is 3–5.5 hours, increasing toas long as 20 hours in patients with severe liver disease.
Drug Indications ::
Indications. Ondansetronis used to treat intractable nausea and vomiting, particularly when theability to administer activated charcoal or antidotal therapy (eg, N-acetylcysteine) is compromised.
Drug Contra-Indications ::
III. Contraindications. Known hypersensitivity to the drug.
Drug Adverse Effects ::
IV. Adverse effects
Bronchospasm, hypersensitivity, and anaphylactoid reactions (rare).
Cardiac arrhythmias, tachycardia, angina, and chest pain (rare).
C. Anxiety, headache, drowsiness, fatigue, fever, and dizziness.
Extrapyramidal reactions may occur.
E. Diarrhea and constipation are both reported.
F. Seizures, hypoxia (rare).
G. Transient blindness (rare).
H. Use in pregnancy. FDA category B. Not likely to cause harm when used as short-term therapy (see Table III–1).
Drug Lab Interactions ::
Drug or laboratory interactions
Extrapyramidal reactions are more likely in patients who are also taking haloperidol or other central dopamine-blocking drugs.
Anticholinergic agents may inhibit bowel motility.
Increased liver transaminases have been reported.
The risk of QT prolongation and cardiotoxicity is increased when ondansetron is used with patients also receiving droperidol.
E.Numerous IV incompatibilities: aminophylline, potassium chloride,sodium bicarbonate, furosemide, lorazepam, dexamethasone,methylprednisolone, sodium succinate, thiopental.
Drug Dose Management ::
Dosage and method of administration. Adults: Give 8 mg or 0.15 mg/kg IV in 50 mL normal saline or 5% dextrose. This may be repeated twice at 4-hour intervals. Alternative high-dose therapy: 32 mg in 50 mL saline or dextrose administered over 15 minutes. (Do not repeat this dose.) Pediatrics: Give 0.15 mg/kg IV. This may be repeated twice at 4-hour intervals.
Ondansetron is most effective when given at least 30 minutes before its antiemetic properties are needed.
Do not exceed a total daily dose of 8 mg in patients with severe liver disease.
Ondansetrondoes not require dilution and can be given by direct intravenousinjection over a period of at least 30 seconds, preferably 2–3 minutes.
Intramuscular use is not recommended.
Drug Chemical Formulations ::
Formulations
Parenteral. Ondansetronhydrochloride (Zofran): 2 mg/mL in 2-mL single-dose vials and 20-mLmultidose vials. Also available as 32 mg in a 50-mL premixed container.
The suggested minimum stocking level to treat a 70-kg adult for the first 24 hours is 32 mg.
