Quick reference
Prophylaxis
- only within 48hrs
- Oseltamivir-7-10 days once daily / Baloxivir- once
Treatment
- give within 48hrs of onset or no effect
- give for high risk population (see below)
- hospitalized
- child <5
- adult >65
- Antiviral therapy is generally recommended for patients admitted to the ICU with influenza pneumonia, even if symptoms began more than 48 hours previously.
- For immunocompetent patients with an illness duration of >4-5 days who appear to have post-influenza bacterial pneumonia, the benefit of antiviral therapy is dubious.
- avoid in everyone else unless patient feels strongly
- pregnancy: oseltamivir only
Oseltamivir
IBCC Pharm reference
Baloxivir
IBCC Pharm reference
There is no evidence to support multiple agents, so choose one.
- 1st line = Oseltamivir 75 mg BID (renal dosing!)
- 2nd line = Peramavir (essentially intravenous oseltamivir for patients who are NPO).
- 3rd line = Baloxavir (possibly consider for patients with contraindications to oseltamavir and peramavir).
high-risk / severe flu
High Risk per 2018 IDSA Guidelines
- Children aged <5 years (especially <2 years)
- Adults aged ≥65 years
- Pregnant and postpartum women (within 2 weeks after delivery)
- Persons with chronic medical conditions (pulmonary including asthma, cardiovascular except hypertension alone, renal, hepatic, metabolic including diabetes, neurologic/neurodevelopmental)
- Immunocompromised individuals (including HIV infection and medication-induced immunosuppression)
- Extreme obesity (BMI ≥40)
- Residents of nursing homes and long-term care facilities
Severe Flu:
Severe influenza - EMCrit Project
- requiring high flow/NIPPV/intubation
- respiratory failure/ARDS
- septic shock
- multisystem organ failure
non-severe flu
- For time to alleviation of symptoms, baloxavir likely reduced symptom duration; oseltamivir and zanamivir likely had no important effect; and umifenovir may have reduced symptom duration.
- Baloxavir did not increase adverse events related to treatment but may have resulted in resistance in approximately 10% of those treated.
- Oseltamivir likely increased risk of adverse events related to treatment.
- high certainty evidence that oseltamivir and zanamivir had little or no effect on hospital admission for high-risk patients
- low certainty evidence that baloxavir may have reduced the risk of hospital admission for high-risk patients.
Tamiflu (Oseltamivir)
2017 Emergency Medicine Article on Tamiflu
- did not result in an important reduction in symptom duration when applying clinically meaningful thresholds
- Increased adverse effects, especially nausea/vomiting
- high certainty that oseltamivir had little or no effect on mortality in both low-risk and high-risk patients
- likely had little or no effect on hospital admission for high-risk patients.
Xofluza(Baloxivir)
- there was no difference in clinical benefit compared with 5 days of oseltamivir.
- maybe decreases hospitalizations
- 10% of baloxavir recipients developed viral escape mutants with reduced drug susceptibility
- most of these patients had infectious virus detected 5 days after treatment and experienced longer symptom duration than baloxavir recipients without these mutations.