ondansetron (Zofran)
Jump to navigation
Jump to search
Introduction
Tradename: Zofran.
Indications
- refractory or severe reactions to standard anti-emetic therapy
- young patients (< 45 years of age) who are more likely to develop extrapyramidal reactions to high-dose metoclopramide
- post-operative nausea & vomiting
- chemotherapy-induced nausea/vomiting[11]
- vomiting in children[5][14]
- refractory nausea/vomiting of pregnancy[10]
- bulimia nervosa[6]
Contraindications
- NOT for use with chemotherapeutic agents with low emetic potential: bleomycin, busulfan, cyclophosphamide (< 1000 mg), etoposide, 5-fluorouracil, vinblastine, vincristine
- congenital long QT syndrome[8]
- hypokalemia or hypomagnesemia[8]
Benefit/risk
- pediatric & adolescent gastroenteritis
- number needed to treat (NNT)
- 5 to stop vomiting[13]
- 6 to prevent dehydration
- no benefit in preventing hospitalization[13]
- no harm noted[13]
- number needed to treat (NNT)
Dosage
- prescribe on a scheduled basis, not on a PRN basis
- 0.15 mg/kg or 12 mg IV over 15 min every 4-8 hours
- decreased effectiveness after 3 doses
- maximum daily dose of 8 mg in patients with cirrhosis
- 8 mg PO TID if > 11 yo
- 4 mg PO TID 4-11 yo
When given with cyclophosphamide (Cytoxan) infusion:
Tabs: 4 & 8 mg.
Adverse effects
- common (> 10%)
- less common (1-10%)
- uncommon (< 1%)
- shortness of breath, wheezing, tachycardia, lightheadedness, seizures, rash, hypokalemia, transient elevations of serum transaminases & bilirubin
- arrhythmias
- QT prolongation including Torsade de Pointes[8]
- other
- use during the 1st trimester of pregnancy doubles the risk of congenital heart disease & cleft palate[12]
Drug interactions
- other drugs that prolong QT interval
Mechanism of action
- acts to prevent nausea, not in the rescue of nausea
- 5-hydroxytryptamine-3 (5HT-3) receptor antagonist[3]
More general terms
References
- ↑ The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
- ↑ Kaiser Permanente Northern California Regional Drug Formulary, 1998
- ↑ 3.0 3.1 Bruera & Neumann Canadian Medical Assoc. J (CAMJ):158:1717, 1998
- ↑ Department of Veterans Affairs, VA National Formulary
resticted to oncology, anesthesiology - ↑ 5.0 5.1 Prescriber's Letter 14(8): 2007 Ondansetron (Zofran) in Children with Viral Gastroenteritis Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=230804&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ 6.0 6.1 Medical Knowledge Self Assessment Program (MKSAP) 14, American College of Physicians, Philadelphia 2006
- ↑ Prescriber's Letter 17(1): 2010 "Off-Label" Uses of Ondansetron COMMENTARY: "Off-Label" Uses of Ondansetron GUIDELINES: CDC Recommendations for Managing Acute Gastroenteritis Among Children GUIDELINES: ACOG Practice Bulletin on Nausea and Vomiting of Pregnancy GUIDELINES: AGA Position Statement on the Use of Gastrointestinal Medications in Pregnancy Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=260108&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 FDA MedWatch Zofran (ondansetron): Drug Safety Communication - Risk of Abnormal Heart Rhythms http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm272041.htm
Ondansetron (Zofran) IV: Drug Safety Communication - QT prolongation http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm310219.htm - ↑ 9.0 9.1 FDA MedWatch: 12/4/2012 Ondansetron (Zofran) 32 mg, Single Intravenous (IV) Dose: Updated Safety Communication - Product Removal due to Potential For Serious Cardiac Risks http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm330772.htm
- ↑ 10.0 10.1 Pasternak B et al. Ondansetron in pregnancy and risk of adverse fetal outcomes. N Engl J Med 2013 Feb 28; 368:814 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/23445092 <Internet> http://www.nejm.org/doi/full/10.1056/NEJMoa1211035
- ↑ 11.0 11.1 Deprecated Reference
- ↑ 12.0 12.1 Prescriber's Letter 21(1): 2014 Ondansetron in Pregnancy-Is it Safe? Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=300109&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ 13.0 13.1 13.2 13.3 The NNT: Ondansetron (Zofran) for Pediatric and Adolescent Gastroenteritis http://www.thennt.com/nnt/ondansetron-for-pediatric-gastroenteritis/
Fedorowicz Z, Jagannath VA, Carter B. Antiemetics for reducing vomiting related to acute gastroenteritis in children and adolescents. Cochrane Database Syst Rev. 2011 Sep 7;(9):CD005506 PMID: https://www.ncbi.nlm.nih.gov/pubmed/21901699
Carter B, Fedorowicz Z Antiemetic treatment for acute gastroenteritis in children: an updated Cochrane systematic review with meta-analysis and mixed treatment comparison in a Bayesian framework. BMJ Open 2012;2:e000622 http://bmjopen.bmj.com/content/2/4/e000622.long - ↑ 14.0 14.1 Bonvanie IJ, Weghorst AA, Holtman GA et al. Oral ondansetron for paediatric gastroenteritis in primary care: A randomised controlled trial. Br J Gen Pract 2021 Oct; 71:e728. PMID: https://www.ncbi.nlm.nih.gov/pubmed/34426397 PMCID: PMC8407859 Free PMC article https://bjgp.org/content/71/711/e728