A 4-year-old girl with community-acquired pneumonia and hypersensitivity to multiple antimicrobial agents improved following a 7-day course of intravenous omadacycline followed by oral doxycycline, without hypersensitivity reactions during omadacycline therapy, according to a case report published in Clinical Case Reports.
The child initially presented with fever to 39 °C, productive cough, and right lung infiltrates on computed tomography. Sputum culture identified Streptococcus pneumoniae resistant to clindamycin, erythromycin, and oxacillin but susceptible to levofloxacin, penicillin, vancomycin, linezolid, and trimethoprim-sulfamethoxazole. Targeted next-generation sequencing of sputum detected Mycoplasma pneumoniae at 2 × 10⁶ copies/mL, S pneumoniae at 1 × 10⁴ copies/mL, Haemophilus influenzae at 7 × 10³ copies/mL, and Moraxella catarrhalis at 4 × 10² copies/mL.
Oral azithromycin was administered for 3 days. Subsequent intravenous therapy with piperacillin-tazobactam, ceftazidime, fosfomycin, and meropenem was discontinued because of generalized pruritic urticaria. Intravenous levofloxacin was also stopped immediately after the patient developed generalized pruritic wheal erythema.
Laboratory evaluation showed a leukocyte count of 7.0 × 10⁹/L on admission. High-sensitivity C-reactive protein decreased from 17 mg/L to 4 mg/L, and procalcitonin was less than 0.1 ng/mL by hospital day 1. Following the onset of vomiting, stool polymerase chain reaction testing was positive for norovirus RNA.
Given the mixed infection and multiple antibiotic allergies, clinicians initiated intravenous omadacycline at a loading dose of 4 mg/kg over 60 minutes, followed by 2 mg/kg once daily over 30 minutes. Dose selection incorporated both weight-based scaling from a standard 70-kg adult and body surface area calculations using the Mosteller formula. A compromise regimen of 50 mg for the loading dose and 25 mg daily for maintenance was administered.
On the first day of therapy, the patient experienced seven episodes of yellow loose diarrhea. Montmorillonite powder, Saccharomyces boulardii, and oral rehydration salts were provided. No cutaneous or systemic hypersensitivity reactions occurred during omadacycline treatment. By day 3, fever had resolved and cough had improved.
Following 7 days of intravenous therapy, the patient transitioned to oral doxycycline 25 mg every 12 hours for 1 week because an oral omadacycline formulation was unavailable and to extend coverage for M pneumoniae. Bronchoscopy with bronchoalveolar lavage, performed for persistent moist rales, showed hyperemic bronchial mucosa and mucus plugs, but no pathogens were identified on smear or culture.
Chest computed tomography at 1 month demonstrated significant regression of right lower lobe consolidation. The patient remained clinically stable at follow-up.
To further evaluate safety, the investigators reviewed reports in the WHO VigiBase database through March 31, 2024. All reports involved patients aged 12 years and older and originated from the Americas. The most frequently reported system organ classes were gastrointestinal, nervous system, and skin disorders; the most common preferred terms were nausea, vomiting, and diarrhea. No pediatric pharmacokinetic data were available.
The researchers acknowledged that the report describes only one patient and did not include a comparison group. Because the child also underwent bronchoscopy and later received doxycycline, it is not possible to determine whether omadacycline alone accounted for the improvement.
“In order to promote the application of omadacycline in the pediatric field, a rigorously designed prospective clinical study is needed to evaluate the safety and efficacy of omadacycline in children with community-acquired pneumonia,” the researchers wrote. They also called for pharmacokinetic studies across pediatric age groups to determine appropriate dosing and for long-term follow-up studies focusing on potential adverse effects such as dental pigmentation and bone development.
The researchers reported no disclosures.
Source: Clinical Case Reports
