What antibiotic and dosage is recommended for a 12-year-old, 57kg girl with community-acquired pneumonia (RML pneumonia)?

From the Guidelines

For a 12-year-old girl weighing 57 kg with right middle lobe (RML) pneumonia, I recommend amoxicillin as first-line therapy at a dose of 90 mg/kg/day divided into two doses (maximum 3 grams daily) as per the guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America 1. This dose is approximately 5130 mg per day, which can be divided into two doses of approximately 2565 mg every 12 hours for 5-7 days. If there is concern for atypical pathogens or if the patient has risk factors for resistant organisms, azithromycin could be added at 10 mg/kg on day 1 (maximum 500 mg) followed by 5 mg/kg (maximum 250 mg) daily for days 2-5 1. For patients with penicillin allergy, alternatives include cefdinir 14 mg/kg/day divided twice daily (maximum 600 mg daily) or, if severe allergy exists, a macrolide alone such as azithromycin 1. Community-acquired pneumonia in children is most commonly caused by Streptococcus pneumoniae, for which amoxicillin provides excellent coverage 1. The high dose is recommended to overcome potential intermediate resistance. If the patient appears toxic, has significant respiratory distress, or requires hospitalization, intravenous antibiotics such as ampicillin or ceftriaxone would be more appropriate 1. Reassessment within 48-72 hours is essential to ensure clinical improvement. Some key points to consider when treating pediatric community-acquired pneumonia include:

• The choice of antibiotic should be based on the severity of the disease, the patient's age, and the presence of any underlying medical conditions 1.
• The duration of treatment should be tailored to the individual patient, but is typically 5-7 days for uncomplicated cases 1.
• Patients with severe disease or those who are not responding to treatment should be reassessed and considered for alternative therapies or hospitalization 1.

From the FDA Drug Label

Community-Acquired Pneumonia The recommended dose of azithromycin for oral suspension for the treatment of pediatric patients with community-acquired pneumonia is 10 mg/kg as a single dose on the first day followed by 5 mg/kg on Days 2 through 5.

PEDIATRIC DOSAGE GUIDELINES FOR OTITIS MEDIA, ACUTE BACTERIAL SINUSITIS AND COMMUNITY-ACQUIRED PNEUMONIA (Age 6 months and above, see PRECAUTIONS—Pediatric Use.)

Based on Body Weight OTITIS MEDIA AND COMMUNITY-ACQUIRED PNEUMONIA: (5-Day Regimen) * Dosing Calculated on 10 mg/kg/day Day 1 and 5 mg/kg/day Days 2 to 5.

Weight100 mg/5 mL200 mg/5 mLTotal mL per Treatment CourseTotal mg per Treatment Course KgLbs. Day 1Days 2–5Day 1Days 2–5

50 and above110 and above12.5 mL (2½ tsp) 6.25 mL (1¼ tsp) 37.5 mL1500 mg

For a 12-year-old girl weighing 57 kg with community-acquired pneumonia, the recommended dose of azithromycin is:

• 10 mg/kg as a single dose on the first day, which is 570 mg (57 kg x 10 mg/kg)
• 5 mg/kg on Days 2 through 5, which is 285 mg (57 kg x 5 mg/kg) Since the patient's weight is above 50 kg, the total dose for the 5-day regimen would be 1500 mg, but this needs to be divided according to the recommended dosing schedule. The dose for this patient would be 570 mg on Day 1 and 285 mg on Days 2-5 2.

From the Research

Antibiotic Choice for Community-Acquired Pneumonia in a 12-Year-Old Girl

• The patient is a 12-year-old girl weighing 57 kg with community-acquired pneumonia.
• According to the study 3, azithromycin is effective in treating community-acquired pneumonia in children, with a satisfactory therapeutic outcome similar to amoxicillin/clavulanate or erythromycin.
• The recommended dose of azithromycin for children is not explicitly stated in the provided studies, but the study 3 mentions that azithromycin was given once daily for 5 days.

Dosing of Azithromycin

• The study 4 mentions that azithromycin 1g once daily for 3 days is effective in treating adult patients with community-acquired pneumonia, but this may not be directly applicable to a 12-year-old girl.
• The study 3 used azithromycin once daily for 5 days in children, but the dose is not specified.
• Without explicit dosing guidelines for a 12-year-old girl, it is difficult to determine the exact dose of azithromycin.

Alternative Antibiotic Choice

• Amoxicillin is also an effective antibiotic for treating community-acquired pneumonia in children, as stated in the study 5.
• The study 6 compared the efficacy of amoxicillin at different doses (35-50 mg/kg/day vs 70-90 mg/kg/day) and durations (3 days vs 7 days) in children with community-acquired pneumonia.
• According to the study 6, amoxicillin at a dose of 35-50 mg/kg/day for 3 days or 7 days is effective in treating community-acquired pneumonia in children.

Dosing of Amoxicillin

• For a 12-year-old girl weighing 57 kg, the dose of amoxicillin would be:

• 35-50 mg/kg/day: 1995-2850 mg/day, which can be divided into 2-3 doses per day.

• The study 6 suggests that a 3-day or 7-day course of amoxicillin is effective, but the exact duration should be determined based on the patient's clinical response.