What antiviral medication is recommended for a 12-year-old female with a 2-day history of fever, cough, and sore throat suspected to be due to influenza?

Antiviral Treatment for 12-Year-Old with Suspected Influenza

Oseltamivir 75 mg orally twice daily for 5 days is the recommended antiviral treatment for this 12-year-old female, given that she presents within 2 days of symptom onset with fever, cough, and sore throat consistent with influenza-like illness. 1

Criteria Met for Antiviral Treatment

This patient meets all three required criteria for oseltamivir therapy in children:

• Acute influenza-like illness (fever, cough, sore throat) 1
• Fever >38.5°C 1
• Symptomatic for ≤2 days (within the 48-hour treatment window) 1

Dosing for This Patient

For a 12-year-old, the dose is 75 mg orally twice daily for 5 days (assuming body weight >24 kg, which is typical for this age). 1 If her weight is between 15-23 kg, use 45 mg twice daily; if <15 kg, use 30 mg twice daily. 1

Expected Clinical Benefits

When initiated within 48 hours of symptom onset, oseltamivir provides:

• Reduction in illness duration by approximately 1.5 days (36 hours) 2, 3
• Reduction in severity of illness by up to 38% 2
• 35-44% reduction in secondary complications requiring antibiotics, particularly otitis media 2, 3
• Faster resolution of fever (approximately 12 hours sooner than placebo) 4

Important Caveats

Earlier treatment is better: The benefit is greatest when started within 24 hours of symptom onset, though treatment within 48 hours still provides benefit. 5 At 2 days of symptoms, this patient is at the outer edge of the optimal treatment window.

Common side effects: Nausea and vomiting occur in approximately 5-6% of children, but are typically mild and transient. 1, 3 Taking oseltamivir with food reduces gastrointestinal symptoms. 2

Diagnostic testing not required: For otherwise healthy outpatient children with typical influenza-like illness during flu season, clinical diagnosis is sufficient and laboratory confirmation is not necessary before initiating treatment. 6, 5

When to Consider Antibiotics

Do not routinely add antibiotics unless there are specific signs of bacterial co-infection. 1 However, consider co-amoxiclav if the patient develops:

• Signs of pneumonia (respiratory distress, hypoxia, chest signs) 1
• Severe illness requiring hospitalization 1
• High-risk features (though this patient appears otherwise healthy) 1

For children under 12 years, co-amoxiclav is the antibiotic of choice if needed, providing coverage against S. pneumoniae, S. aureus, and H. influenzae. 1, 7

Red Flags Requiring Hospital Assessment

Advise the family to seek immediate medical attention if the child develops:

• Respiratory distress (increased respiratory rate, grunting, intercostal retractions, breathlessness) 1, 7
• Cyanosis or oxygen saturation ≤92% 1, 7
• Severe dehydration or inability to maintain oral intake 1, 7
• Altered level of consciousness 1, 7
• Signs of septicemia 1, 7

Conflicting Evidence Note

While older guidelines strongly support oseltamivir use 1, 2, 3, one recent 2022 study found no significant benefit in reducing fever duration or symptom severity in children. 8 However, the weight of guideline evidence and multiple controlled trials supports treatment, particularly given the demonstrated reduction in complications and antibiotic use. 2, 3 The 2006-2007 British Infection Society and British Thoracic Society guidelines remain the authoritative source for this clinical scenario. 1