Alerts
Oseltamivir (Tamiflu) Oral Suspension—Potential for Dosing Errors
September 28, 2009
FDA issued a public health alert warning pharmacists and prescribers about the potential for medication errors with oseltamivir (Tamiflu) oral suspensions. Oseltamivir is dosed in milligrams (mg) while most oral suspensions are dosed in teaspoons or milliliters (mL). A dosing device is provided with the oseltamivir oral suspension and contains graduations for 30, 45, and 60 mg doses. Cases have occurred in which the dosing instructions written on the prescription were not equivalent to the units on the dosing device and dosing errors were made. FDA has requested physicians write prescriptions for oseltamivir suspension in milligram doses and pharmacists verify patient instructions correlate to the units on the dosing dispenser. If a prescription is written with milliliter dosing instructions, dispense the medication with a calibrated syringe measuring milliliters rather than the milligram dosing device. Oseltamivir oral suspension dosed in teaspoons may result in inaccurate dosing and should be avoided. Compounding instructions are available if the commercial oseltamivir oral suspension is not available. The table below provides oseltamivir dosing information for children over the age of one.
| Weight (kg) | Treatment Dose (twice daily for 5 days) | Prophylactic Dose (once daily for 10 days) | Number of Tamiflu bottles needed | Number of Tamiflu capsules needed | ||
| mg | mL | mg | mL | |||
| ≤ 15 kg | 30 mg | 2.5 mL | 30 mg | 2.5 mL | 1 | Ten 30 mg capsules |
| > 15 kg | 45 mg | 3.8 mL | 45 mg | 3.8 mL | 2 | Ten 45 mg capsules |
| > 23 to 40 kg | 60 mg | 5.0 mL | 60 mg | 5.0 mL | 2 | Twenty 30 mg capsules |
| > 40 kg | 75 mg | 6.2 mL | 75 mg | 6.2 mL | 3 | Ten 75 mg capsules |
More information on this topic is available through the following links.
- FDA MedWatch Report:
http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm183714.htm - FDA Public Health Alert:
http://www.fda.gov/Drugs/DrugSafety/InformationbyDrugClass/ucm183649.htm - Dear Healthcare Professional Letter:
http://www.fda.gov/downloads/Safety/MedWatch/SafetyInformation/ SafetyAlertsforHumanMedicalProducts/UCM183752.pdf - Information for Pharmacists on 2009-2010 Influenza Season:
http://www.cdc.gov/H1N1flu/pharmacist/pharmacist_info.htm - Emergency Use of Tamiflu in Infants Less than 1 Year of Age:
http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm183870.htm - Emergency Compounding of Tamiflu Oral Suspension from Tamiflu Capsules:
http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm183878.htm
Updated
September 28, 2009; University of Utah, Drug Information Service. Copyright 2009, Drug Information Service, University of Utah, Salt Lake City, UT.
