What is the recommended treatment for influenza (flu) in a 23-month-old child?

Treatment of Influenza in a 23-Month-Old Child

Oral oseltamivir should be initiated immediately at 45 mg twice daily for 5 days in this 23-month-old child with suspected or confirmed influenza. 1

Why Treat This Age Group

Children younger than 2 years are at significantly increased risk for influenza-related hospitalization and complications, making antiviral treatment particularly important in this population. 2, 1 The American Academy of Pediatrics specifically recommends antiviral treatment for all children under 2 years with suspected influenza, regardless of vaccination status or illness severity. 2, 1

Dosing for a 23-Month-Old

For a child 23 months of age, the weight-based dosing is critical:

• If weight is >15-23 kg: 45 mg twice daily for 5 days 1
• If weight is ≤15 kg: 30 mg twice daily for 5 days 1
• If weight is >23-40 kg: 60 mg twice daily for 5 days 1

Most 23-month-old children fall into the 15-23 kg range, making 45 mg twice daily the most likely appropriate dose. 1

Formulation and Administration

Oseltamivir is available as an oral suspension at 6 mg/mL concentration in a 60-mL bottle, which is ideal for this age group. 2, 1 If the commercially manufactured suspension is unavailable, capsules can be opened and mixed with simple syrup or Ora-Sweet SF by a pharmacist to achieve the same 6 mg/mL concentration. 2

Timing Is Critical

Treatment should be initiated as soon as possible, ideally within 48 hours of symptom onset, without waiting for laboratory confirmation. 2, 1 Earlier treatment provides substantially greater benefit—when started within 12 hours, oseltamivir can reduce illness duration by an additional 74.6 hours compared to treatment started at 48 hours. 3 In children 1-3 years with influenza A, treatment within 24 hours shortened illness by 3.5 days and reduced acute otitis media by 85% when started within 12 hours. 4

However, even if more than 48 hours have passed, treatment should still be offered to this high-risk child, as benefits have been demonstrated even with later initiation in young children. 2, 1

Expected Benefits

In this age group, oseltamivir treatment provides:

• Reduction in illness duration by 36 hours (26% decrease) 2
• 34% lower risk of acute otitis media, a common complication in young children 2, 1
• Decreased risk of hospitalization and other serious complications 2

Common Side Effects to Anticipate

Diarrhea is the most common side effect in children under 1 year of age, occurring in approximately 7% of treated infants. 2, 1 Vomiting may also occur but is generally mild and transient. 2 These gastrointestinal symptoms can be minimized by administering the medication with food. 3, 5

Despite historical concerns from Japan, controlled clinical trials and ongoing surveillance have failed to establish any link between oseltamivir and neuropsychiatric events. 2, 1

Safety Netting: When to Seek Immediate Care

Parents should be instructed to return immediately if the child develops:

• Difficulty breathing, fast breathing, or chest retractions 1
• Fever persisting beyond 3-4 days or returning after initial improvement 1
• Seizures, altered mental status, or extreme irritability 1
• Signs of dehydration (decreased urination, no tears when crying, extreme lethargy) 1

Alternative Agents (Not Recommended for This Age)

Inhaled zanamivir is more difficult to administer and is not practical for a 23-month-old. 2 Intravenous peramivir is FDA-approved only for children 2 years and older with acute uncomplicated influenza who are not hospitalized and have been symptomatic for no more than 2 days—this child does not meet age criteria. 2, 6 Additionally, peramivir's efficacy in severe or hospitalized cases has not been established. 7, 6

Critical Clinical Pitfall to Avoid

Do not delay treatment while waiting for laboratory test results. 1, 7 Rapid antigen tests have low sensitivity and negative results should never be used to rule out influenza or withhold treatment in this high-risk age group. 1 Clinical diagnosis during influenza season is sufficient to initiate therapy. 2, 1

Infection Control Measures

Limit the child's exposure to other household members, especially infants under 6 months or individuals with underlying medical conditions. 1 Practice rigorous hand hygiene for all household members. 1 Consider prophylactic oseltamivir for high-risk household contacts if they were exposed within the last 48 hours. 1