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Content Update
August 15, 2019
Baloxavir Approved as Novel Treatment for Influenza: The U.S. Food and Drug Administration approved baloxavir marboxil as a new antiviral treatment for influenza on October 24, 2018. The CDC now recommends baloxavir as one of the four FDA-approved antiviral drugs for treatment of seasonal influenza. Baloxavir is administered as a single dose and works by a novel antiviral mechanism of action on influenza RNA polymerase. It has been shown in randomized controlled trials to be comparable to oseltamivir for reducing duration of flu symptoms and serum viral load when given within 48 hours in cases of uncomplicated influenza. There is not yet sufficient literature on baloxavir’s efficacy or adverse events in patients younger than twelve, pregnant women, or hospitalized patients with more severe disease presentations.
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Content Update
March 12, 2019
Updated IDSA Guidelines on Seasonal Influenza: The Infectious Diseases Society of America (IDSA) updated the 2009 clinical practice guidelines for the diagnosis, treatment, chemoprophylaxis, and institutional outbreak management of seasonal influenza. The document provides new information and recommendations on diagnostic testing, use of antivirals, and testing for antiviral resistance. It also presents evidence on harm associated with routine use of corticosteroids. These updated guidelines should be adopted by all primary care providers.
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Patient Care Process for Influenza Infection Treatment
Collect
Patient characteristics; age; health conditions; occupation; travel; lifestyle, current health status, present & past medical history; allergies
Medication history (include prescription, nonprescription and other substances); vaccination history; pregnancy status
Microbiologic results from rapid respiratory viral panel and secondary bacterial infection. Bacterial susceptibility tests when available. (see Clinical Presentation: Diagnosis of Infection)
Laboratory results for infection, major organ function (particularly kidney and liver), immune status, lactate
Assess
Assess for medication contraindications and drug interactions
Determine severity of illness based on vital signs, acute organ dysfunction, source control (or lack thereof)
Determine likely pathogens for secondary bacterial infection of the respiratory tract, patient's microbiologic history, previous antibiotic exposure, and response to current therapy
Determine if other conditions are present such as chronic lung disease likely to affect outcomes of infection.
Estimate creatinine clearance for drug dosing.
Plan
Strongly recommend future influenza vaccine if no contraindication is present (Table 109-2)
Initiate treatment neuraminidase therapy—oral, inhaled, or IV, based on severity of illness (Table 109-5 and 6)
Determine influenza treatment goals of therapy with monitoring parameters for each goal.
Determine appropriate antibiotic therapy for secondary bacterial infection and monitoring plan
Establish antimicrobial monitoring goals for efficacy (e.g., resolution of infection, clearance of bacteria from blood cultures) and drug toxicity
Check for drug interactions and dose adjustments based on end-organ function
Implement
Initiate a neuraminidase inhibitor and continue for ~7 days after identification of illness onset in the last patient (prophylaxis for community outbreak) or 5 days (treatment) or establish tentative stop date for severely ill patients.
If secondary bacterial infection suspected, initiate empiric antimicrobial regimen, and deescalate ...