What is the recommended management for a 17-year-old with influenza (flu)?

Management of Influenza in a 17-Year-Old

For a 17-year-old with influenza, initiate oseltamivir 75 mg orally twice daily for 5 days as soon as possible, ideally within 48 hours of symptom onset, though treatment should not be withheld even if presenting later in high-risk patients or those with severe illness. 1

Treatment Indications

Treatment with oseltamivir should be offered for:

• Any hospitalized patient with suspected or confirmed influenza 1
• Patients at high risk of complications, including those with chronic medical conditions (asthma, diabetes, immunosuppression, neurologic disorders) 1
• Severely ill patients regardless of time since symptom onset 1, 2
• Otherwise healthy adolescents when symptom reduction is desired, particularly if treatment can be initiated within 48 hours 1

Dosing for 17-Year-Olds

Oseltamivir 75 mg orally twice daily for 5 days is the standard dose for adolescents 13 years and older, regardless of weight if >40 kg (>88 lb) 1, 3

• Can be taken with or without food, though administration with meals improves gastrointestinal tolerability 1, 3
• Complete the full 5-day course regardless of symptom improvement 3
• For renal impairment (creatinine clearance 10-30 mL/min), reduce to 75 mg once daily for 5 days 1, 3

Timing of Treatment

Optimal benefit occurs when treatment starts within 48 hours of symptom onset, reducing illness duration by approximately 1-1.5 days 2, 4. However, critical nuances exist:

• Treatment initiated within 12 hours of fever onset reduces illness duration by 3.1 days (41% reduction) compared to treatment at 48 hours 5
• Do not withhold treatment if presenting after 48 hours in patients with moderate-to-severe or progressive disease, as mortality benefit persists even with delayed initiation 2, 3
• Treatment should be started empirically based on clinical suspicion during influenza season without waiting for laboratory confirmation 1, 2

Alternative Antiviral Options

If oseltamivir cannot be used:

• Zanamivir (inhaled): 10 mg (two 5-mg inhalations) twice daily for 5 days, approved for patients ≥7 years; avoid in patients with asthma or COPD 1, 3
• Peramivir (IV): Single 600 mg IV infusion over 15-30 minutes for ages 13-17 years 1, 3
• Baloxavir (oral): Single dose based on weight (40 mg for 40-80 kg, 80 mg for ≥80 kg) for patients ≥12 years 1, 3

Expected Clinical Benefits

• Reduces illness duration by 17.6-29.9 hours in otherwise healthy patients 2
• Decreases risk of pneumonia by 50% in patients with laboratory-confirmed influenza 2
• Reduces risk of otitis media by 34% in younger patients 2
• Significant mortality benefit in hospitalized patients (OR 0.21 for death within 15 days) 2

Common Pitfalls to Avoid

• Do not delay treatment while awaiting laboratory confirmation in high-risk or severely ill patients, as rapid antigen tests have poor sensitivity and negative results should not exclude treatment 1, 2
• Do not withhold treatment based solely on time since symptom onset if the patient has moderate-to-severe illness or high-risk features 2, 3
• Do not routinely prescribe antibiotics unless bacterial co-infection is documented or highly suspected 3, 6
• Do not use amantadine or rimantadine due to widespread resistance 3

Adverse Effects

• Nausea and vomiting are the most common side effects, occurring in approximately 15% of treated patients vs 9% on placebo 2, 5
• Vomiting is transient, rarely leads to discontinuation, and can be minimized by taking with food 2, 5
• No established link between oseltamivir and neuropsychiatric events has been confirmed 2

Supportive Care

In addition to antiviral therapy:

• Acetaminophen for fever management 7
• Adequate hydration 7
• Rest and symptom monitoring for complications 4