Oseltamivir on the Move, but Where Should It Go?
Just as influenza season started ramping up in the Northern Hemisphere, news hit the wire that Sanofi had secured over-the-counter rights for oseltamivir (Tamiflu).
Just as influenza season started ramping up in the Northern Hemisphere, news hit the wire that Sanofi had secured over-the-counter rights for oseltamivir (Tamiflu). The news caused a flurry of interest and speculation among the infectious disease community about the implications this change would have on patient care.
The move raises many questions: Can patients self-diagnose influenza? What will be the impact on antiviral resistance? Will it be safe? Will patients with comorbidities or severe disease seek emergency care when necessary? Will it disincentivize vaccination? Where is the greater good—expanded access or clinician-guided expertise?
Many of these questions are difficult to answer, but a few have data. Patients are not good at self-diagnosing influenza, as they both overdiagnose and underrecognize the condition.1 In fact, the confusion is understandable, as the spectrum of symptoms of influenza is more variable than commonly thought.2 Oseltamivir resistance in influenza viruses varies annually and has been detected in both patients treated with oseltamivir and antiviral-naïve populations, particularly children.3 Amantadine resistance is so common as to make it useless for influenza. Continued antiviral pressure will likely increase resistance. The US Food and Drug Administration will determine the safety of oseltamivir for outpatient use, although it has a long record of safety.
The remaining questions are less clear. However, 1 potential solution splits the difference between prescription-only and over-the-counter status, possibly offering the benefits of expanded access but retaining a level of professional assessment: a third medication category, namely pharmacist prescription. The shift in pharmacy education to clinical curricula that occurred in the past 20 years has led to overtrained and underutilized clinician resources in most pharmacies. The availability of point-of-care assays for influenza in pharmacies could improve diagnoses that would otherwise go undetected.4 Pilot studies have shown that these can be used effectively in community pharmacies with screening tools and education that refer patients to hospitals and physicians when circumstances such as severe disease or significant comorbidities dictate.5
Currently, pharmacist-prescribed medications are allowed on a state-by-state basis and for particular medication classes, such as oral contraceptives. Pharmacist vaccination is approved in all 50 states. In addition, nearly all states (48 as of 2018) allow collaborative practice agreements for pharmacists prescribing via protocols in association with other professionals through collaborative practice agreements, but these are limited to the individual practitioners who establish them. Perhaps most dramatically, as I noted in the last issue of Contagion®, California passed bill SB 159 to allow HIV postexposure prophylaxis and preexposure prophylaxis to be dispensed by pharmacists who are adequately trained.7
The motive to move oseltamivir is financial, designed to sell it to as many patients as possible. Because the US Food and Drug Administration will consider it from the primary perspective of safety, it is likely to occur. Let’s look at this opportunity to examine the issue with a broader perspective to see what we can do to improve care while we deliberate where this agent should go.
As always, enjoy this issue, and keep up with us at ContagionLive.com.
Gallagher is a clinical professor at Temple University School of Pharmacy and clinical pharmacy specialist in infectious diseases at Temple University Hospital, both in Philadelphia, Pennsylvania. He is also the director of the PGY2 Residency in Infectious Diseases Pharmacy at Temple.* indicates active member of the Society of Infectious Diseases Pharmacists.
References:
1. Jutel A, Baker MG, Stanley J, Huang QS, Bandaranayake D. Self-diagnosis of influenza during a pandemic: a cross-sectional survey. BMJ Open. https://bmjopen.bmj.com/content/1/2/e000234.full.
2. Jutel A, Banister E. “I was pretty sure I had the 'flu”: qualitative description of confirmed-influenza symptoms. Soc Sci Med. 2013;99:49-55.
3. Poland GA, Jacobson RM, Ovsyannikova IG. Influenza virus resistance to antiviral agents: a plea for rational use. Clin Infect Dis. 2009;48(9):1254-1256. https://doi.org/10.1086/598989.
4. Kozel TR, Burnham-Marusich AR. Point-of-care testing for infectious diseases: past, present, and future. J Clin Microbiol. 2017;55:2313-2320. https://doi.org/10 .1128/JCM.00476-17.
5. Klepser D, Klepser ME, Murry JS, Borden H, Olsen KM. Evaluation of a community pharmacy-based influenza and group A streptococcal pharyngitis disease management program using polymerase chain reaction point-of-care testing. J Am Pharm Assoc. 2019;59:872-879. doi: 10.1016/j.japh.2019.07.011.
6. Weaver KK. Collaborative practice agreements: explaining the basics. Pharmacy Today. 2018;24(3):55. https://www.pharmacytoday.org/article/S1042-0991(18)30260-3/fulltext.
7 .Gallagher, J. The Year ends with a big step in PrEP and PEP. Contagion. 2019; https://www.contagionlive.com/publications/contagion/2019/december/the-year-ends-with-a-big-step-in-prep-and-pep
