Antiviral Therapies for Influenza: Examining the Therapeutic Benefits and Reductions in Influenza-Related Complications

Inflluenza treatment was a timely topic discussed during the 2020 virtual Directions in Pharmacy® conference. Rupal Mansukhani, PharmD, FAPhA, CTTS, presented a review of antiviral therapies to improve patient outcomes and reduce influenza-related complications.

Dr Mansukhani began the discussion with a summary of influenza epidemiology, etiology, and pathophysiology. The burden of disease was emphasized, noting an estimated 39 million to 56 million influenza illnesses between October 1, 2019, and April 4, 2020. Further, she highlighted how specific patient populations (eg, pregnant or older patients, those with chronic diseases) are at higher risk of developing flu-related complications and stressed the importance of keeping these patient populations in mind.

Dr Mansukhani then discussed antiviral treatment recommendations, which stress initiating treatment early (ie, not waiting for laboratory confirmation). Testing for influenza depends on access to testing and the clinical status of the patient, as a negative result does not preclude a patient from treatment, and false positives and/or negatives may occur.

Antivirals in the setting of influenza are used prophylactically or for treatment. Currently, there are 3 classes approved by the FDA: adamantanes (eg, amantadine, rimantadine), neuraminidase inhibitors (eg, oseltamivir, peramivir, and zanamivir), and a cap-dependent endonuclease inhibitor (baloxavir). Adamantanes have fallen out of favor due to their high levels of resistance and are not recommended. Initiation of several of these agents (eg, neuraminidase inhibitors) is recommended within 48 hours of symptoms and some have warnings and precaution of severe rashes and neuropsychiatric effects.

Dr Mansukhani then discussed the most recently approved baloxavir marboxil, an oral agent approved in 2018 as a weightbased, single-dose treatment in patients 12 years or older who are otherwise healthy or at high risk of developing influenzarelated complications. She discussed a new drug application accepted by the FDA for treatment of acute uncomplicated influenza in otherwise healthy children aged 1 year to less than 12 years who have been symptomatic for no more than 48 hours. This agent has administration requirements, such as no dairy, antacids, calcium, or certain laxatives. Baloxavir’s efficacy was established in 2 randomized clinical trials (CAPSTONE 1 & 2) in which baloxavir was superior to placebo and noninferior to oseltamivir. Patients with uncomplicated acute influenza should receive neuraminidase inhibitors or baloxavir, whereas those with severe illness who are hospitalized should receive oseltamivir.

MINISTONE-2 evaluated the efficacy of baloxavir in children aged 1 to 12 years with influenza and found comparable efficacy to oseltamivir with fewer adverse effects and less length of time for viral shedding. Baloxavir’s utility in influenza prevention was assessed in the phase 3 trial BLOCKSTONE, which demonstrated a significantly lower risk of infection versus placebo. The safety of baloxavir was comparable to oseltamivir with a safety signal for hypersensitivity being closely monitored.

Dr Mansukhani wrapped up the discussion by stressing the role of the pharmacist, including patient education, identifying high-risk patients, recommending antiviral treatment, and the expansion of immunization services to improve outcomes and decrease influenza-related complications.

RUPAL MANSUKHANI, PharmD, FAPhA, CTTS, is a clinical associate professor at the Ernest Mario School of Pharmacy at Rutgers University. She completed her Doctor of Pharmacy degree in 2004 at the Philadelphia College of Pharmacy. Upon graduation, she completed a PGY-1 Community Practice Residency at the University of Illinois in Chicago. Until 2012, she worked in community practice at Pathmark Pharmacy, where she taught students about clinical outpatient services. She currently practices at Morristown Medical Center in transitions of care. Her areas of interest include respiratory conditions, such as chronic obstructive pulmonary disease, asthma, and pneumonia, with a special interest in advancing immunization rates. Advancing patient care and promoting pharmacy through research, scholarly activities, and presentations have also been fundamental to Dr Mansukhani’s approach to moving the profession of pharmacy forward. She has presented her research at local, regional, national, and international meetings. She is passionate about teaching and continues to improve immunization rates within her state.