II. Indications
- Chemotherapy associated Nausea
- Radiation Therapy associated Nausea
- Vomiting refractory to first-line Antiemetics
-
Theophylline
Overdose
- Used instead of Phenothiazines due to Seizure risk
III. Contraindications
- QTc Prolongation (see adverse effects below)
IV. Mechanism
- See 5-HT3 Receptor Antagonist
- Blocks peripheral and central 5HT3 receptors
- Peripheral 5HT3 receptors at vagal nerve terminals
- Central 5HT3 receptors at ChemoreceptorTrigger Zone in Medulla (area postrema controls Vomiting)
V. Dosing
- Dose Adjustments
- Severe Liver Disease: Max dose 8 mg orally, 16 mg IV
-
Gastroenteritis
- Adults
- Take 4 mg ODT tabs (typical acute care dosing)
- Children
- Exercise caution in age <6 months
- Weight 8-15 kg: Ondansetron 2 mg (half tab)
- Weight 15-30 kg: Ondansetron 4 mg (one tab)
- Weight >30 kg: Ondansetron 4 to 8 mg (one to two tabs)
- Freedman (2006) N Engl J Med 354:1698-705 [PubMed]
- Adults
-
Nausea with Chemotherapy
- Timing
- First dose: 30 minutes before Chemotherapy
- Subsequent dosing: 4 and 8 hours after first dose
- Thereafter, may repeat every 12 hours for 1-2 days after Chemotherapy
- Intravenous dosing
- Adult: 8 to 16 mg IV over 15 min
- Child (over age 6 months): 0.15 mg/kg up to 8 to 16 mg IV over 15 min
- Oral dosing (ODT)
- Over age 12 years: 8 mg orally twice to three times daily
- Age 4 to 11 years: 4 mg orally twice to three times daily
- Age under 4 years: 0.15 mg/kg/dose (up to 4 mg) orally twice to three times daily
- Timing
-
Nausea with Radiation Therapy (adult)
- Dose: 8 mg orally three times daily
- Surgery Related Nausea (Prevention and Treatment of Post-Operative Nausea and Vomiting)
- Adult
- Prevention: 8 to 16 mg orally 1 hour before surgery
- Treatment: 4 mg IM or IV over 2-5 minutes
- Child
- Age 1 month to 12 years (weight <40 kg): 0.1 mg/kg up to 4 mg IV over 2 to 5 min given 30 min before surgery
- Age >12 years (weight >40 kg): 4 mg IV over 2 to 5 min given 30 min before surgery
- Efficacy
- Meta-analysis of 7 randomized trials, n=1043
- Works in only 25% of patients
- No more effective than less expensive drugs
- Tramer (1997) BMJ 314:1088-93 [PubMed]
- Adult
VI. Adverse Effects
- Mild Headache
- Dizziness
- Malaise or Fatigue
- Constipation
-
QT Prolongation
- Risk Factors
- Single doses >16 mg IV
- Preexisting QTc Prolongation (avoid)
- If QTc is already prolonged, Metoclopramide (Reglan) is a safe alternative without risk of QTc Prolongation
- Congestive Heart Failure
- Bradycardia
- Hypomagnesemia
- Hypokalemia
- Unlikely to cause harm (even at highest dose, Ondansetron prolongs QTc only 20 ms)
- Risk Factors
- Serotonin Syndrome
VII. Safety
- Unknown safety in Lactation
- First trimester pregnancy
- Ondansetron has a relative contraindication based on preliminary data
- Previously thought to be safe in pregnancy
- However it is also frequently used in Hyperemesis Gravidarum
- FDA cautions use in Gestational age <10 weeks
- As of 2013, Ondansetron may be associated with 2 fold increased risk of congenital malformations
- References
- Ondansetron has a relative contraindication based on preliminary data
VIII. Drug Interactions
-
Apomorphine
- Drug Interaction with risk of hyoptension, Altered Level of Consciousness
IX. Resources
X. References
- Johnson (1993) Harriet Lane, Mosby, p. 521
- Hamilton (2020) Tarascon Pocket Pharmacopoeia
- (1998) Med Lett Drugs Ther 40(1026): 53-4 [PubMed]
- (1991) Med Lett Drugs Ther 33(847): 63-4 [PubMed]
- Bell and Lovecchio (2016) Crit Dec Emerg Med 30(8): 28
Images: Related links to external sites (from Bing)
Related Studies
ondansetron (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
ONDANSETRON 4 MG/5 ML SOLUTION | Generic | $0.25 per ml |
ONDANSETRON HCL 4 MG TABLET | Generic | $0.07 each |
ONDANSETRON HCL 4 MG/2 ML VIAL | Generic | $0.18 per ml |
ONDANSETRON HCL 8 MG TABLET | Generic | $0.10 each |
ONDANSETRON ODT 4 MG TABLET | Generic | $0.18 each |
ONDANSETRON ODT 8 MG TABLET | Generic | $0.20 each |
Ontology: Ondansetron (C0061851)
Definition (NCI) | A carbazole derivative with antiemetic activity. As a selective serotonin receptor antagonist, ondansetron competitively blocks the action of serotonin at 5HT3 receptors, resulting in suppression of chemotherapy- and radiotherapy-induced nausea and vomiting. (NCI04) |
Definition (NCI_NCI-GLOSS) | The active ingredient in a drug used to treat nausea and vomiting caused by cancer treatment. Ondansetron is a type of serotonin receptor antagonist and a type of antiemetic. |
Definition (MSH) | A competitive serotonin type 3 receptor antagonist. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties. |
Definition (CSP) | competitive serotonin type 3 receptor antagonist used in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs; also has anxiolytic and neuroleptic properties. |
Definition (PDQ) | A carbazole derivative with antiemetic activity. As a selective serotonin receptor antagonist, ondansetron competitively blocks the action of serotonin at 5HT3 receptors, resulting in suppression of chemotherapy- and radiotherapy-induced nausea and vomiting. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=40693&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=40693&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C1119" NCI Thesaurus) |
Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
MSH | D017294 |
SnomedCT | 108418007, 372487007 |
LNC | LP171625-9 |
English | 4H-Carbazol-4-one, 1,2,3,9-tetrahydro-9-methyl-3-((2-methyl-1H-imidazol-1-yl)methyl)-, ondansetron, ondansetron (medication), ONDANSETRON, Ondansetron [Chemical/Ingredient], ONAD, Ondansetron, Ondansetron, (+,-)-Isomer, Ondansetron (product), Ondansetron (substance) |
Swedish | Ondansetron |
Czech | ondansetron |
Finnish | Ondansetroni |
Russian | ONDANSETRON, ОНДАНСЕТРОН |
Japanese | オンダンセトロン |
Croatian | ONDANSETRON |
Spanish | ondansetrona, ondansetrón (producto), ondansetrona (producto), ondansetrona (sustancia), ondansetrón (sustancia), ondansetrón, Ondansetrón |
Polish | Ondansetron |
French | Ondansétron |
German | Ondansetron |
Italian | Ondansetrone |
Portuguese | Ondansetron |
Ontology: Zofran (C0206046)
Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
MSH | D017294 |
English | zofran, Zofran |