Swine Flu (Influenza A H1N1) Treatment

• Rest and adequate fluids
• Antipyretics/analgesics (paracetamol or ibuprofen) for fever, body aches, headache
• Isolation for about 5-7 days from symptom onset (or until 24 hours symptom-free) to limit spread
• Monitoring for warning signs of deterioration

• Oseltamivir (Tamiflu) - oral, first-line; adult dose typically 75 mg twice daily for 5 days (dose adjusted in renal impairment, and weight-based in children)
• Zanamivir (Relenza) - inhaled, alternative if oseltamivir isn't tolerated or resistance is suspected
• Peramivir - IV formulation, used in hospitalized/severe cases who cannot take oral/inhaled drugs

• Hospitalized patients
• Pregnant women
• Children under 5 (especially under 2)
• Adults over 65
• People with chronic conditions: asthma/COPD, diabetes, heart disease, chronic kidney or liver disease, immunosuppression, morbid obesity
• Anyone with severe, complicated, or progressive illness (e.g., dyspnea, hypoxia, chest pain, altered mental status)

• Oxygen supplementation, and mechanical ventilation or ECMO if severe ARDS develops
• IV fluids and hemodynamic support
• Treatment of secondary bacterial pneumonia with antibiotics if superinfection is suspected (H1N1 predisposes to bacterial pneumonia, notably from Streptococcus pneumoniae and Staphylococcus aureus, including MRSA)
• Close monitoring for complications: viral pneumonia, ARDS, myocarditis, encephalitis, multi-organ failure

• Antibiotics have no role unless there's a confirmed or strongly suspected secondary bacterial infection
• Aspirin should be avoided in children and teenagers due to Reye syndrome risk

• Annual influenza vaccination (seasonal vaccines now typically include an H1N1 component)
• Hand hygiene, respiratory etiquette, avoiding close contact when symptomatic
• Post-exposure prophylaxis with oseltamivir or zanamivir can be considered for high-risk contacts

Swine Flu (Influenza A H1N1) Treatment

• Rest and adequate fluids
• Antipyretics/analgesics (paracetamol or ibuprofen) for fever, body aches, headache
• Isolation for about 5-7 days from symptom onset (or until 24 hours symptom-free) to limit spread
• Monitoring for warning signs of deterioration

• Oseltamivir (Tamiflu) - oral, first-line; adult dose typically 75 mg twice daily for 5 days (dose adjusted in renal impairment, and weight-based in children)
• Zanamivir (Relenza) - inhaled, alternative if oseltamivir isn't tolerated or resistance is suspected
• Peramivir - IV formulation, used in hospitalized/severe cases who cannot take oral/inhaled drugs

• Hospitalized patients
• Pregnant women
• Children under 5 (especially under 2)
• Adults over 65
• People with chronic conditions: asthma/COPD, diabetes, heart disease, chronic kidney or liver disease, immunosuppression, morbid obesity
• Anyone with severe, complicated, or progressive illness (e.g., dyspnea, hypoxia, chest pain, altered mental status)

• Oxygen supplementation, and mechanical ventilation or ECMO if severe ARDS develops
• IV fluids and hemodynamic support
• Treatment of secondary bacterial pneumonia with antibiotics if superinfection is suspected (H1N1 predisposes to bacterial pneumonia, notably from Streptococcus pneumoniae and Staphylococcus aureus, including MRSA)
• Close monitoring for complications: viral pneumonia, ARDS, myocarditis, encephalitis, multi-organ failure

• Antibiotics have no role unless there's a confirmed or strongly suspected secondary bacterial infection
• Aspirin should be avoided in children and teenagers due to Reye syndrome risk

• Annual influenza vaccination (seasonal vaccines now typically include an H1N1 component)
• Hand hygiene, respiratory etiquette, avoiding close contact when symptomatic
• Post-exposure prophylaxis with oseltamivir or zanamivir can be considered for high-risk contacts

Latest CDC/WHO Guidelines for Influenza A(H1N1) Management

• Oseltamivir (Tamiflu, generic available) - oral
• Zanamivir (Relenza) - oral inhalation
• Peramivir (Rapivab) - IV
• Baloxavir marboxil (Xofluza) - a cap-dependent endonuclease inhibitor (single-dose oral), the newer addition to the arsenal alongside the three older neuraminidase inhibitors

• Clinicians do not need lab confirmation to start treatment - if flu is suspected in a patient at high risk of complications, treat immediately based on clinical judgment
• Antiviral treatment is prioritized for: hospitalized patients, and outpatients at higher risk of complications (young children, adults ≥65, pregnant women, people with chronic medical conditions, immunosuppressed, morbidly obese)
• Adamantanes (amantadine, rimantadine) remain not recommended - high-level resistance persists in circulating A(H1N1)pdm09 and A(H3N2) strains
• CDC's antiviral susceptibility surveillance for 2025-2026 has been expanded (in-state partner testing), but no drastic resistance changes have been detected, so treatment guidance is unchanged from previous seasons
• Vaccine composition for 2025-26 includes an updated H1N1 component (A/Victoria/4897/2022-like for egg-based vaccines, or A/Wisconsin/67/2022-like for cell/recombinant vaccines), per the ACIP/MMWR update

• Antiviral treatment (neuraminidase inhibitors, primarily oseltamivir) recommended for patients with severe or progressive illness, hospitalized patients, and those at high risk of complications, regardless of confirmed subtype
• Supportive care remains foundational for uncomplicated cases in low-risk patients
• Recommendations are evidence-graded (GRADE methodology) and apply broadly across influenza A subtypes, including H1N1

• Antiviral treatment (oseltamivir first-line) for hospitalized children or those at high risk of complications, started as early as possible
• Annual vaccination for all children ≥6 months without contraindications