When should oral antibiotics be started after administering a single intramuscular (IM) dose of ceftriaxone (a third-generation cephalosporin antibiotic)?

From the Guidelines

Oral antibiotics should be started 24 hours after administering a single IM dose of ceftriaxone, if clinical improvement is observed. According to the clinical practice guideline for the diagnosis and management of acute bacterial sinusitis in children aged 1 to 18 years 1, a single 50-mg/kg dose of ceftriaxone can be used for children who are vomiting, unable to tolerate oral medication, or unlikely to be adherent to the initial doses of antibiotic. The guideline suggests that if clinical improvement is observed at 24 hours, an oral antibiotic can be substituted to complete the course of therapy.

Key Considerations

• The 3 major bacterial pathogens involved in acute bacterial sinusitis are susceptible to ceftriaxone in 95% to 100% of cases 1.
• Children who are still significantly febrile or symptomatic at 24 hours may require additional parenteral doses before switching to oral therapy 1.
• The optimal duration of antimicrobial therapy for patients with acute bacterial sinusitis has not received systematic study, but recommendations based on clinical observations have varied widely, from 10 to 28 days of treatment 1.

Oral Antibiotic Options

• Amoxicillin remains the antimicrobial agent of choice for first-line treatment of uncomplicated acute bacterial sinusitis in situations in which antimicrobial resistance is not suspected 1.
• For children aged 2 years or older with uncomplicated acute bacterial sinusitis that is mild to moderate in degree of severity who do not attend child care and who have not been treated with an antimicrobial agent within the last 4 weeks, amoxicillin is recommended at a standard dose of 45 mg/kg per day in 2 divided doses 1.
• High-dose amoxicillin-clavulanate (80–90 mg/kg per day of the amoxicillin component with 6.4 mg/kg per day of clavulanate in 2 divided doses with a maximum of 2 g per dose) may be used for patients presenting with moderate to severe illness as well as those younger than 2 years, attending child care, or who have recently been treated with an antimicrobial 1.

From the Research

Transitioning to Oral Antibiotics

• The decision to transition from intramuscular (IM) ceftriaxone to oral antibiotics depends on various factors, including the type of infection, patient's condition, and susceptibility of the pathogen 2, 3.
• Studies suggest that oral cefixime can be an effective alternative to IV ceftriaxone for the treatment of severe upper urinary tract infections, with a possible transition to oral antibiotics on the 5th day 2.
• The timing of transition to oral antibiotics can vary, but it is often considered when the patient's condition has improved and the pathogen and its susceptibility have been determined 3, 4.
• A study found that transitioning patients from IV to oral therapy by day 7 was highly variable across hospitals, ranging from 25.8% to 65.9% 4.
• Common oral antibiotics used for transition include fluoroquinolones, β-lactams, and trimethoprim-sulfamethoxazole 4.

Factors Influencing Transition

• Patient's clinical stability, with most patients achieving stability within 5 days 4.
• Source control, with successful source control by day 7 associated with a higher likelihood of transition to oral therapy 4.
• Infection source, with urinary tract, hepatobiliary, and intra-abdominal infections being common sources among patients administered oral therapy 4.
• Immunocompromised status, with patients who are immunosuppressed being less likely to be transitioned to oral therapy 4.

Oral Antibiotic Options

• Cefixime, a third-generation cephalosporin, has been shown to be effective against various pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 5.
• Other oral antibiotics, such as ciprofloxacin, have been found to be effective and safe for the treatment of acute invasive diarrhea in children 6.