A 4-month old girl is brought to the GP by her mother for a two-day history of fever of 101F.
On examination she appears healthy. There is no rash present. Soft expiratory crackles are
auscultated diffusely across both lung fields. What is the most appropriate treatment for this
patient?
- A) Ribavirin
- B) Palivizumab
- C) Motavizumab
- D) Inhaled corticosteroid
- E) Oral corticosteroid
- F) Antibiotic therapy
- G) Supportive care
0 voters
EXP:
Respiratory syncytial virus (RSV) bronchiolitis is the most common cause of bronchiolitis in
infants and young children and accounts for approximately 125,000 hospitalizations and 250 infant
deaths every year in the United States. Peak incidence occurs at 2-3 months of age.1 RSV is
responsible for 50%–90% of children hospitalized for bronchiolitis.2Approximately two-thirds of
infants are infected with RSV during the first year of life, and 90% have been infected one or more
times by 2 years of age.3
Treatment is largely supportive (i.e., fluid replenishment and oxygen if needed).4, 5
Ribavirin
Ribavirin, an RNA polymerase inhibitor, is the only FDA-approved treatment for RSV.5, 6 However
the current (as of 2019) recommendation is that it should not be routinely used due to a
combination of its cost and adverse effect profile.7
• “Ribavirin is licensed for use as a treatment for infants with bronchiolitis. However, the most
recent Cochrane review of its use in 2007 suggested that the available evidence at that time was
insufficient to confidently state whether or not ribavirin is clinically effective at treating RSV
bronchiolitis. Therefore, due to its side-effect profile and lack of reproducible data on efficacy it
is not currently recommended for routine use in RSV bronchiolitis in infants in the UK or US.
The inhaled form of the drug is also extremely costly with wholesale prices for a single day of
treatment quoted at US$29,000 in the US.”7
Palivizumab and motavizumab
• Both monoclonal antibodies against RSV F-protein.7
Palivizumab is sometimes as prophylaxis, never as treatment.5
• Indications for Palivizumab5
• Preterm neonates <35 weeks gestation
• Neonates with congenital heart or lung disease
• Motavizumab is 20x more potent than palivizumab but is not recommended for use due to lack
of safety and clinical efficacy data.5
Corticosteroids, both inhaled and oral, are not indicated in the treatment of RSV.5
Bottom line: RSV is the most common cause of bronchiolitis in infants and young children;
peak incidence is at 2-3 months of age. Treatment is supportive care only. Ribavirin is not
frequently used as treatment and is the wrong answer on the USMLE. Palivizumab is used rarely as
prophylaxis, not treatment, in neonates born <35 weeks gestation or who have congenital heart or
lung disease. Motavizumab is a newer and more potent version of palivizumab but is not indicated
for use due to lack of safety and clinical efficacy data.