What is the treatment for melioidosis?

Treatment of Melioidosis

Treat melioidosis with a two-phase approach: an intensive phase using intravenous meropenem or imipenem for at least 14 days, followed by an eradication phase with oral trimethoprim-sulfamethoxazole (TMP-SMX) for 3-6 months. 1, 2

Initial Intensive Phase (Minimum 14 Days)

First-Line Therapy

• Meropenem or imipenem are the preferred agents for severe melioidosis, demonstrating superior clinical outcomes compared to ceftazidime. 1
• Standard dosing: meropenem 1-2g IV every 8 hours or imipenem 1g IV every 6-8 hours 1

Alternative Therapy

• Ceftazidime 100 mg/kg/day (divided doses) is acceptable if carbapenems are unavailable, though observational data show inferior outcomes in severe disease 1, 2

Extended Intensive Phase Indications

• Continue IV therapy beyond 14 days for: critical illness/septic shock, extensive pulmonary disease, deep-seated abscesses, osteomyelitis, septic arthritis, or neurologic involvement 1, 2
• For CNS melioidosis specifically, extend to 4-8 weeks or longer and add high-dose TMP-SMX 8/40 mg/kg IV/PO every 12 hours (maximum 320/1600 mg) 1

Adjunctive Therapy

• Consider adding G-CSF 300 mg IV for 10 days in patients with melioidosis-induced septic shock 1, 3

Eradication Phase (3-6 Months)

First-Line Therapy

• TMP-SMX is the drug of choice for eradication, with monotherapy as effective as combination regimens in preventing relapse. 1, 2

Weight-Based Dosing for TMP-SMX

• <40 kg: 160/800 mg (1 DS tablet) twice daily 1
• 40-60 kg: 240/1200 mg (1.5 DS tablets) twice daily 1
• >60 kg: 320/1600 mg (2 DS tablets) twice daily 1
• Add folic acid 0.1 mg/kg up to 5 mg daily to prevent antifolate effects 1

Extended Eradication Duration

• Extend to 4-8 months or longer for CNS involvement, osteomyelitis, or septic arthritis 1

Alternative Eradication Regimens

• Amoxicillin-clavulanate 20/5 mg/kg every 8 hours (maximum 1500/375 mg every 8 hours) is the preferred alternative for pregnant women, children, or TMP-SMX-intolerant patients, though significantly less effective than first-line therapy 1, 2
• Doxycycline can be used if TMP-SMX is contraindicated 1, 2

Critical Resistance Patterns to Avoid

Inherently Resistant Antibiotics

• Never use: penicillin, ampicillin, first- and second-generation cephalosporins, gentamicin, streptomycin, polymyxin, ertapenem, azithromycin, or moxifloxacin 1, 3
• Avoid ceftriaxone and cefotaxime as these are associated with higher mortality rates compared to ceftazidime 1

Post-Exposure Prophylaxis

• Administer TMP-SMX (co-trimoxazole) within 24 hours of exposure for immunosuppressed patients or following potential biological attack, with animal studies showing 100% survival when given within this timeframe 1, 3

Common Pitfalls

• Misdiagnosis: Melioidosis often mimics tuberculosis, pneumonia, or other pyogenic infections; maintain high clinical suspicion in endemic areas with fever, progressive pneumonia, or sepsis 4
• Premature discontinuation: The full 3-6 month eradication phase is critical, as relapse rates reach 13% over 10 years without adequate treatment 1
• Laboratory misidentification: VITEK systems may misidentify Burkholderia pseudomallei; use selective culture media like Ashdown's agar in endemic areas 1
• Delayed therapy: Start empirical treatment in clinically probable cases even before bacteriological confirmation, as delays lead to poor outcomes 1, 4