Oseltamivir (Tamiflu) for Children, Maybe Not a Magic Pill

Tamiflu for KidsMaking a patient feel better is empowering and rejuvenates our professional spirits. This is why we all love taking care of the patient with a Patellar Dislocation, Shoulder Dislocation, or a Nursemaid’s elbow. Obviously, administering Adenosine for SVT can make you feel like a magician also! Unfortunately, the availability of Magic Medicine is limited. Even more unfortunate, our patients are often preconditioned to look for a magic pill. This flu season has been challenging, on multiple fronts, because patients have been told of the importance of Oseltamivir (Tamiflu). I, personally, however, have not seen a magic pill in our clinical environments. When something seems to be incongruent, I look to see what the Cochrane Library has to say. Let us review what is known about oseltamivir today (and actually since 2014):

 

Influenza

  • Influenza is highly contagious.
  • Influenza can may cause mild disease, but can also lead to severe illness and complications. [CDC, Disease Burden]
  • There are special populations who are at greater risk from the disease:
    • >65 years of age
    • Pregnant (and up to 2 weeks post partum)
    • Residents of long-term care facilities
    • Children <5 years of age (particularly <2 years of age)
    • Patient with chronic medical problems, like asthma (see CDC list)

 

Influenza: Therapies(?)

  • The Center for Disease Control (CDC) currently states:
    • “Prescription medications called ‘antiviral drugs’ … can be used to treat flu illness.” (CDC.gov)
    • “It’s very important that flu antiviral drugs are started as soon as possible to treat: (CDC.gov)
    • “…most people who are otherwise healthy and get the flu do not need to be treated with antiviral drugs.” (CDC.gov)
  • The available “therapies” for children:
    • Peramivir – for patients 2 years and older (only in IV form)
    • Zanamivir – for patients 7 years and older (not for pts with asthma)
    • Oseltamivir – for patients 14 days and older

 

Oseltamivir and Neuraminidase Inhibitors: The Problem

  • Much of the the justification for recommendations and stockpiling are based on pharmaceutical company-based research. [Gupta, 2015]
    • Not that industry-sponsored research is unable to generate important information and be valuable… but…
    • These particular studies, when re-reviewed, had issues: [Jefferson, 2014]
      • The original detailed data was not made easily available.
      • Definitions of disease and complications were vague.
      • Placebo interventions (when used) may have had active substances.
  • In order to address developing concerns about zanamivir and oseltamivir, Jefferson et al.: [Jefferson, 2014]
    • Did not use the journal publications (as there was publication bias and discrepancies).
    • Instead, obtained the manufacturers’ reports to regulators and the regulators’ comments.
      • These are unpublished, extensive documents with great detail on the trials that formed the basis for market approval.
      • They include the protocols, methods and results.
      • They are typically confidential – seen only by the manufacturers and regulators.
    • After review of this information, found “substantial problems with the design, conduct, reporting, and availability of information from many trials.”
  • Based on this re-review, several areas of potential bias were found:
    • Performance Bias – from differences in care provided to participants.
    • Selection Bias – there was inadequate reporting to understand how groups were assigned to therapies
    • Attrition Bias – participants who drop out (possible due to side-effects) not being included in the results.

 

Oseltamivir: What is Concluded

  • For adults, Oseltamivir (Tamiflu): [Jefferson, 2014]
    • Reduced time to alleviation of symptoms by 16.8 HOURS.
    • Prophylactic use can reduce the risk of developing symptomatic influenza.
    • Had no significant effect on hospitalizations.
    • Did not reduce complications classified as serious.
    • Did not reduce the otitis media or sinusitis.
    • May have reduced self-reported, unverified pneumonia (lack of definition)
    • Side-effects seen:
      • Nausea with Number Needed to Harm (NNTH) = 28
      • Vomiting with NNTH = 22
      • Dose-response effect on psychiatric events.
      • Headache, renal and psychiatric events seen during prophylaxis therapy.
  • In children, Oseltamivir (Tamiflu): [Jefferson, 2014]
    • Reduced time to alleviation of symptoms by 29 HOURS in healthy children.
    • Had NO SIGNIFICANT effect in children with asthma (one of the high risk groups).
    • Had NO SIGNIFICANT effect in hospitalizations.
    • Had NO SIGNIFICANT effect in prophylaxis.
    • Did not reduce complications classified as serious.
    • Did not reduce the otitis media or sinusitis.
    • Did not have an effect on unverified pneumonia.
    • Nausea is seen frequently as side-effect with NNTH = 19

 

Moral of the Morsel

  • Don’t be Biased! Regardless of where research originates from, its conclusions may be substantially influenced by numerous biases… good study design aims to help reduce this risk.
  • Don’t be Bullied! Understand the recommendations… but also their limitations. Asthma may place a patient in the high risk category, but there is no evidence that a child with asthma benefits from oseltamivir.
  • Weigh Risk and Benefit! We do this with all conditions, evaluations, and therapies… hopefully this Morsel will help you with the true weight of the items in this specific equation.
  • Educate Your Patients and Their Families! This goes without saying… but is the most important.

 

References

Gupta YK1, Meenu M1, Mohan P1. The Tamiflu fiasco and lessons learnt. Indian J Pharmacol. 2015 Jan-Feb;47(1):11-6. PMID: 25821304. [PubMed] [Read by QxMD]

Jefferson T1, Jones MA, Doshi P, Del Mar CB, Hama R, Thompson MJ, Spencer EA, Onakpoya I, Mahtani KR, Nunan D, Howick J, Heneghan CJ. Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children. Cochrane Database Syst Rev. 2014 Apr 10;(4):CD008965. PMID: 24718923. [PubMed] [Read by QxMD]

Sean M. Fox
Sean M. Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renowned educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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4 Comments

  1. Sean,

    AWESOME job on this week’s morsel. This provides clarity on what has been a very confusing flu season in regards to CDC recs. I continue to read your morsels every single week and appreciate them so much. Keep up the great work!

    Seth
    Niswonger Children’s ED – Johnson City, TN

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