Despite health care providers’ and public health agencies’ efforts to encourage annual flu shots for everyone, many people still contract influenza. When patients contract the flu, health care professionals have options that can reduce influenza-related complications and mortality rates. Rupal Mansukhani, PharmD, FAPhA, CTTS, from the Ernest Mario School of Pharmacy, Rutgers University, in Piscataway, New Jersey, presented an overview of novel antivirals that will accomplish this goal at the 9th annual Directions in Pharmacy conference.

Dr. Mansukhani immediately engaged the audience by explaining that the word “influenza” originated in the 15th century in Italy. A contagious respiratory illness was epidemic among Italians, and they attributed it to the stars’ influence. Influenza causes fever, cough, sore throat, muscle or body aches, and fatigue. Influenza’s complications—not its symptoms—are most troublesome. If pneumonia develops or influenza exacerbates pulmonary or cardiac conditions, patients are in serious trouble.

After a brief review of the epidemiology of influenza, including the differentiation between influenza A and influenza B, Dr. Mansukhani described influenza nomenclature and concisely discussed historic pandemics. Then, she launched into a discussion of high-risk populations, which include patients who are hospitalized; very young; very old; diagnosed with chronic pulmonary, cardiovascular, renal, hepatic, neurologic, hematologic, or metabolic disease; immunocompromised, pregnant or recovering from delivery; children receiving long-term aspirin therapy; long-term care facility residents; American Indians/ Alaska natives; or morbidly obese.

Dr. Mansukhani stressed that vaccines are our primary mechanism of prevention. Health care professionals need to continue to promote vaccinations, citing excellent evidence that vaccination prevents 7 million cases of flu every year as well as 109,000 hospitalizations and 8000 deaths.

The FDA has approved several medications to prevent or treat influenza. These include amantadine, rimantadine, oseltamivir, zanamivir, peramivir, and baloxavir. Dr. Mansukhani noted that although all of these medications are FDA approved, the Advisory Committee on Immunization Practices (ACIP) does not recommend use of amantadine or rimantadine.

Dr. Mansukhani discussed adverse effects of neuraminidase inhibitors, including serious skin reactions, anaphylaxis and toxic epidermal necrolysis, Stevens-Johnson syndrome, and erythema multiforme. These symptoms require drug discontinuation. Some neuropsychiatric events (eg, delirium and abnormal behavior), primarily in pediatric patients, have been observed. Influenza in general can precipitate abnormal behavior, hallucinations, and delirium, and researchers are unsure why this occurs either with influenza or pursuant to the neuraminidase inhibitors. Dr. Mansukhani also noted that oseltamivir contains 2 grams of sorbitol per dose; patients with hereditary fructose intolerance cannot take this drug. It is also contraindicated in individuals who have end-stage renal disease who are not undergoing dialysis.

Zanamivir may cause sinusitis or dizziness. Individuals who have underlying respiratory disease, such as asthma or chronic obstructive pulmonary disease, should not use zanamivir. Peramivir, which is approved for inpatient administration in individuals older than 2 years, is not recommended for prevention. For all of these drugs, administration within 48 hours of the first signs of flu is optimal. Treatment with neuraminidase inhibitors decreases the chance of pneumonia.

Baloxavir has a novel mechanism of action as a cap-dependent endonuclease inhibitor that prevents viral gene transcription and replication. Given as 1 dose in individuals who are aged 12 years or older, it, too, is best administered within 48 hours of the first signs of flu. Pharmacists should counsel patients to avoid dairy, calcium-fortified beverages, laxatives, antacids, and oral supplements. Common adverse effects include diarrhea, bronchitis, nasopharyngitis, headache, and nausea. Resistance to the neuraminidase inhibitor antivirals is possible and has been documented, and pharmacists should be aware of that possibility.

In summary, Dr. Mansukhani reminded pharmacists to ensure that the medication they select is approved for prevention or treatment (as appropriate to the patient’s situation), make sure that the medication is age-appropriate, and to watch contraindications. Pharmacists should consider expanding immunization services with standing orders once they understand how to recommend and prescribe antiviral therapy. Many pharmacies are establishing collaborative practice agreements to do just this.