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Antivirals for influenza: Nursing Pharmacology


amantadine (Symmetrel), rimantadine (Flumadine)
baloxavir marboxil (Xofluza)

oseltamivir phosphate,(Tamiflu), peramivir (Rapivab), zanamivir (Relenza)

Endonuclease inhibitor
Neuraminidase inhibitors
Stop viral replication and the release of new influenza viruses
Prophylaxis of influenza
Acute treatment of influenza
Prophylaxis and acof influenza
  • PO
  • PO (oseltamivir) 
  • IV (peramivir)
  • INH (zanamivir)
  • Gastrointestinal disturbances: nausea, vomiting, dyspepsia, diarrhea
  • Neuropsychiatric symptoms: delirium, delusions, hallucinations
  • Serious hypersensitivity reactions (Stevens- Johnson syndrome, toxic epidermal necrolysis, erythema multiforme)
  • Pregnancy and breastfeeding 
  • Renal or hepatic disease 
  • Respiratory disease (asthma, COPD)
Assessment and monitoring
  • Vital signs
  • Current symptoms; timing of symptom onset
  • Laboratory test results: rapid antigen testing, RT-PCR

  • Side effects
  • Therapeutic effect: reduced flu symptoms

Client education
  • Purpose of the medication: helps reduce severity and duration of influenza symptoms
  •  Take medication twice daily
    • With or without food
    • Most effective if started within 48 hours of symptom onset
  • Does not prevent the spread of the virus to others
    • Follow infection prevention guidelines
  • Rest and fluids to promote recovery
  • Side effects 
    • Headache, nausea, vomiting, diarrhea
    • Contact their healthcare provider
      • Dermatological reactions: blistered, swollen, or peeling skin
      • Behavioral symptoms: confusion, tremors, hallucinations
  • Remember to get the influenza vaccine every year before the influenza season begins

The influenza virus causes seasonal influenza, commonly called “the flu”, which is one of the most common infectious diseases. There are several antiviral medications that can be used either in the prevention of influenza for high-risk clients, or in the acute treatment of severe cases of influenza.

Alright, so, the most commonly used antivirals for influenza include neuraminidase inhibitors, such as oseltamivir, peramivir, and zanamivir; as well as endonuclease inhibitors like baloxavir marboxil.

Also, there are additional antivirals that are currently not recommended, including adamantanes, such as amantadine and rimantadine. Most of these antivirals are taken orally, except for peramivir, which is given intravenously, and zanamivir, which comes in a powder form that is inhaled by mouth.

Once administered, each class of antiviral act through a different mechanism of action. Neuraminidase inhibitors, as their name implies, bind and inhibit the viral enzyme neuraminidase, thereby preventing the release of new viruses.

Endonuclease inhibitors, on the other hand, inhibit, you guessed it, a viral enzyme called endonuclease, ultimately stopping the transcription of viral RNA. Finally, adamantanes act by inhibiting the viral protein M2, which prevents viruses from replicating inside the host cell. Ultimately, all of these antivirals help stop viral replication and the release of new influenza viruses.

However, these medications also come with side effects. Luckily, these are usually mild, and they mainly refer to gastrointestinal disturbances, such as nausea, vomiting, stomach pain, and diarrhea.

Less commonly, antiviral medications for influenza can cause neuropsychiatric symptoms, such as delirium, delusions, and hallucinations. In addition, some clients can develop serious hypersensitivity reactions, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and erythema multiforme. Finally, clients taking zanamivir can present with bronchospasms.

Now, antivirals for influenza should be used with caution during pregnancy and breastfeeding, as well as with infants, children, and elderly clients, as well as clients with underlying respiratory disease, such as asthma or chronic obstructive pulmonary disease. Additional precautions should be taken in clients with severe renal or hepatic disease.

Now, when your client with influenza is prescribed oseltamivir, perform a baseline physical assessment, including vital signs and their current symptoms such as fever, chills, cough, congestion, fatigue, body aches, and ask when they first noticed their symptoms. Lastly, check your client’s laboratory test results such as rapid antigen testing or reverse transcription polymerase chain reaction or RT-PCR for short.