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

Treatment of Influenza

Nonpharmacologic Treatment

Nonpharmacologic recommendations for influenza are bed rest, avoidance of other persons, and hydration. Fluids should be consumed throughout the illness to prevent complications from dehydration. Acetaminophen or ibuprofen may be used to relieve fever, headache, and muscle aches. However, some patients may benefit from antiviral treatment (see Pharmacotherapy Considerations section).[17–19]

Pharmacologic Agents

Antiviral medications with activity against influenza viruses are an important adjunct to vaccination for control of the influenza virus. Oseltamivir (Tamiflu), inhaled zanamivir (Relenza), and IV peramivir (Rapivab) are the currently recommended agents for influenza.[20–22] These drugs, which are neuraminidase inhibitors with activity against both influenza A and influenza B, work by selectively inhibiting the neuraminidase enzyme, thereby preventing the release of viral particles from infected cells. These medications may be used for treatment, but only oseltamivir and zanamivir may be used for treatment and chemoprophylaxis. The chemoprophylaxis dosages for these drugs are lower than the treatment dosages; however, the therapy duration is longer (Table 1).[20–23] Oseltamivir and zanamivir are indicated for use in adults and children; peramivir has not been FDA-approved for use in children.[19,23]

Besides the neuraminidase inhibitors, two other products are available: amantadine (Symmetrel) and rimantadine (Flumadine), both of which are adamantane antiviral agents with activity against influenza A viruses. These agents exert an inhibitory effect on influenza A subtypes (H1N1, H2N2, and H3N2) early in the viral replicative cycle. However, they are no longer recommended for treatment and prevention of influenza because of the increased rates of resistance (>99%) in influenza A types H3N2 and H1N1.[19,23]

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