Co-trimoxazole Dosing for Burkholderia cepacia Infection
For Burkholderia cepacia infection, co-trimoxazole (trimethoprim-sulfamethoxazole) should be dosed at TMP 15-20 mg/kg plus SMX 75-100 mg/kg daily, divided into 2-4 doses, administered intravenously for severe infections or orally for mild-to-moderate cases. 1
Intensive Phase Treatment
For severe or invasive B. cepacia infections, the treatment approach mirrors that used for melioidosis (caused by the related organism Burkholderia pseudomallei):
- Intensive phase duration: 14 days of high-dose intravenous therapy 1
- Dosing by weight:
Eradication Phase Treatment
Following the intensive phase, transition to oral therapy for prolonged eradication:
- Continue oral co-trimoxazole at the same weight-based dosing for an extended period 1
- Add folic acid supplementation: 0.1 mg/kg up to 5 mg PO daily to prevent antifolate effects without compromising antimicrobial activity 1
- Duration: Several months may be required for complete eradication, particularly in immunocompromised patients 1
Alternative Agents When Co-trimoxazole Cannot Be Used
When co-trimoxazole is contraindicated due to allergy, intolerance, or resistance, consider these alternatives based on susceptibility testing:
- Ceftazidime: Most effective alternative with 86-96% susceptibility rates; dosed at 50 mg/kg (up to 2 g) IV q6-8h 1, 2, 3
- Meropenem: 83% susceptibility; dosed at 1 g IV q8h or 25 mg/kg (up to 1 g) IV q8h 1, 2, 3
- Piperacillin-tazobactam: 91-96% susceptibility; dosed at 4.5 g IV q6h 2, 4
Clinical Context and Susceptibility
The evidence strongly supports co-trimoxazole as first-line therapy:
- Susceptibility rates: 71-89% of B. cepacia isolates remain susceptible to co-trimoxazole 3, 5, 6
- Clinical outcomes: Treatment with effective antibiotics including co-trimoxazole is associated with favorable prognosis 3
- Resistance patterns: While B. cepacia shows intrinsic resistance to aminoglycosides and many beta-lactams, co-trimoxazole maintains good activity 2, 5
Important Monitoring Requirements
During co-trimoxazole therapy for B. cepacia:
- Start prophylaxis one week after purine analogue administration if used concurrently to reduce allergic skin reactions 1
- Monitor for hypersensitivity reactions: Rash, photosensitivity, and Stevens-Johnson syndrome can occur 7
- Watch for gastrointestinal effects: Nausea, vomiting, and diarrhea are common 7
- Check drug interactions: Particularly with anticoagulants, methotrexate, and phenytoin 7
Special Populations
Immunocompromised patients require particular attention:
- 68% of pediatric B. cepacia infections occur in patients with underlying conditions 3
- ICU patients account for 84% of cases and require aggressive treatment 3
- Recurrence rates are high (50%) at median 7.8 months, necessitating prolonged therapy 4
Common Pitfalls to Avoid
- Do not use aminoglycosides alone: All strains show resistance to aminoglycosides 5
- Avoid empiric piperacillin-tazobactam without susceptibility data: Some studies show >55% resistance rates 3
- Do not discontinue therapy prematurely: B. cepacia requires prolonged treatment courses to prevent recurrence 4
- Always obtain susceptibility testing: Resistance patterns vary by institution and geographic region 7, 3