What are the recommended medications for a 13-year-old female patient with influenza (flu)?

Treatment of Influenza in a 13-Year-Old Female

Oseltamivir 75 mg orally twice daily for 5 days is the recommended treatment, initiated as soon as possible and ideally within 48 hours of symptom onset. 1, 2, 3

Primary Antiviral Treatment

• Oseltamivir (Tamiflu) is the antiviral drug of choice for adolescents 13 years and older with influenza 4, 1, 3
• The standard dose is 75 mg orally twice daily for 5 days for patients weighing over 40 kg 1, 2, 3
• Treatment can be taken with or without food, though administration with meals improves gastrointestinal tolerability and may reduce nausea 1, 3

Timing of Treatment Initiation

• Start treatment immediately upon clinical suspicion—do not delay while awaiting laboratory confirmation 4, 1, 2
• Greatest benefit occurs when initiated within 48 hours of symptom onset, reducing illness duration by approximately 17.6-29.9 hours 1, 5
• Even if presenting beyond 48 hours, treatment should still be considered if the patient has moderate-to-severe or progressive symptoms 4, 1

Expected Clinical Benefits

• Reduces illness duration by approximately 17.6-29.9 hours in otherwise healthy patients 1, 5
• Decreases risk of pneumonia by 50% 1
• Reduces risk of otitis media by 34% 1, 2
• Provides significant mortality benefit in hospitalized patients (OR 0.21 for death within 15 days) 1

Alternative Antiviral Options

If oseltamivir is not available or not tolerated, consider:

• Zanamivir (inhaled): 10 mg (two 5-mg inhalations) twice daily for 5 days, approved for patients 7 years and older 1
• Baloxavir (oral): Single dose of 40 mg for patients 40-80 kg (or 80 mg if ≥80 kg), approved for patients 12 years and older 1
• Peramivir (IV): Single 600 mg IV infusion over 15-30 minutes for ages 13-17 years 1

Common Side Effects and Precautions

• Vomiting occurs in approximately 15% of treated adolescents versus 9% on placebo, but effects are mild, transient, and rarely lead to discontinuation 1
• Other gastrointestinal symptoms include nausea, abdominal pain, and diarrhea 5
• Despite historical concerns, controlled clinical trials have failed to establish a link between oseltamivir and neurologic or psychiatric events 2

Supportive Care Measures

• Antipyretics can be used for fever and myalgias, but aspirin must be avoided in patients <19 years due to Reye's syndrome risk 1, 5
• Adequate hydration and rest are important supportive measures 1
• Monitor for warning signs requiring urgent evaluation: difficulty breathing, persistent high fever beyond 3-4 days, altered mental status, or clinical deterioration 1

Critical Pitfalls to Avoid

• Do not withhold treatment based solely on time since symptom onset if the patient has moderate-to-severe illness or high-risk features 1
• Do not delay treatment while awaiting laboratory confirmation in suspected cases, as clinical judgment based on symptoms and local influenza activity should guide immediate treatment decisions 4, 1, 2
• Never use aspirin for symptom management in this age group due to Reye's syndrome risk 1, 5
• Negative rapid antigen tests should not rule out influenza or prevent treatment, as these tests have poor sensitivity 2