Antiviral Therapy in Patients With Influenza

Marie Welch, PharmD; Casey Mabus, PharmD; John A. (Jake) Galdo, PharmD, BCPS, BCGP

Disclosures

US Pharmacist. 2017;42(4):32-36. 

In This Article

Abstract and Introduction

Abstract

Less than 50% of the U.S. population obtains the seasonal influenza vaccine, and the vaccine does not confer perfect immunity. There are three types of influenza, plus numerous variations. Practitioners should be confident in the use of antiviral agents in patients with influenza. The most recent guidelines recommend the use of nonpharmacologic management and neuraminidase inhibitors to either prevent the transmission of influenza or treat the infection. Pharmacotherapy is based on an understanding of which patients are at high risk for complications—including immunocompromised persons, those aged 65 years and older, and those younger than 2 years of age—and prompt treatment upon diagnosis.

Introduction

Influenza viruses remain the most common cause of respiratory infections and result in high morbidity and mortality, especially among young children, the elderly, and immunocompromised persons. The virus consists of three types—influenza A, influenza B, and influenza C—but influenza C is rarely seen. Influenzas B and C are isolated mostly in humans, whereas influenza A, the most common type, infects several mammals, including—but not limited to—birds, swine, and humans.[1]

Influenza pandemics date back to the 1700s; the deadliest one, which occurred in 1918, was responsible for 675,000 deaths in the United States.[1] The most recent pandemic, in 2009, was due to the H1N1 influenza virus (also known as swine flu) and caused 12,469 deaths in the U.S.[2] At the end of 2016, the hospitalization rate was 3.1 per 100,000 population, with the greatest percentage of adults aged 65 years and older.[3]

Prevention is a key component in reducing the rates of influenza-related death and hospitalization. Aggregate data from the CDC, via the National Immunization Survey-Flu and the Behavioral Risk Factor Surveillance System, however, indicate that only 41.7% of the population received seasonal influenza coverage in 2015–2016.[4] This leaves more than one-half of the U.S. population without preventive care.

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