What fraction of a 30mg Tamiflu (oseltamivir) tablet should be mixed with 10ml of water to achieve a 22mg dose?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: October 24, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

How to Calculate Tamiflu Dosage for 22mg from a 30mg Tablet

To achieve a 22mg dose of Tamiflu (oseltamivir) from a 30mg tablet, you should mix the entire tablet with 10ml of water and then administer 7.3ml of this suspension.

Calculation Method

  • For the 6 mg/mL commercial suspension, a 30mg dose is given with 5mL of oral suspension 1
  • When mixing a 30mg tablet with 10mL of water, the concentration becomes 3mg/mL (30mg ÷ 10mL) 2
  • To calculate the volume needed for 22mg:
    • 22mg ÷ 3mg/mL = 7.3mL 2

Administration Guidelines

  • Oseltamivir is available as Tamiflu in 30mg, 45mg, and 75mg capsules and as a powder for oral suspension 1, 3
  • When the commercially manufactured oral suspension is not available, tablets can be mixed with a sweetened liquid 1
  • For accurate dosing, use an appropriate oral dosing device that can measure the calculated volume precisely 2

Important Considerations

  • Administration with meals may improve gastrointestinal tolerability 3, 2
  • Ensure the tablet is completely dissolved in water before administering the calculated dose 2
  • After mixing, the suspension should be used immediately for best results 2
  • Oseltamivir is most effective when started within 48 hours of symptom onset 4

Dosing in Special Populations

  • For patients with renal impairment (creatinine clearance 10-30 mL/min), dose adjustments are recommended 3
  • For preterm infants, lower weight-based dosing is recommended due to immature renal function 1, 3
  • Weight-based dosing is preferred for children, with specific recommendations based on body weight 1

Common Side Effects

  • Nausea and vomiting are the most commonly reported adverse events 5, 6
  • These gastrointestinal effects are typically mild and transient 6
  • Taking oseltamivir with food can reduce these side effects 4, 6

References

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.