Mediastinitis related to perioral or parapharyngeal infection in patients without sepsis or septic shock
For empirical therapy of mediastinitis related to perioral or parapharyngeal infection in adults and children 2 months or older without sepsis or septic shock, use:
2+0.2 g formulation
adult, or child 40 kg or more: 2+0.2 g 8-hourly. For dosage adjustment in adults with kidney impairment, see amoxicillin+clavulanate intravenous dosage adjustment
OR
1+0.2 g formulation
adult, or child 40 kg or more: 1+0.2 g 6-hourly. For dosage adjustment in adults with kidney impairment, see amoxicillin+clavulanate intravenous dosage adjustment
child younger than 3 months and less than 4 kg: 25+5 mg/kg 12-hourly
child younger than 3 months and 4 kg or more: 25+5 mg/kg 8-hourly
child 3 months or older and less than 40 kg: 25+5 mg/kg up to 1+0.2 g 8-hourly. If the child has an abscess, use 6-hourly dosing
OR as a 2-drug regimen
2cefazolin 2 g (child: 50 mg/kg up to 2 g) intravenously, 8-hourly. For dosage adjustment in adults with kidney impairment, see cefazolin dosage adjustment. See below for modification and duration of therapy cefazolin cefazolin cefazolin
PLUS
metronidazole 500 mg (child: 12.5 mg/kg up to 500 mg) intravenously, 12-hourly. See below for modification and duration of therapy. metronidazole metronidazole metronidazole
For patients who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin, use cefazolin plus metronidazole (see dosage above).
For patients who have had severe immediate1 hypersensitivity reaction to a penicillin, cefazolin plus metronidazole (at the dosages above) can be considered if a beta-lactam antibiotic is strongly preferred (for considerations, see Severe immediate hypersensitivity: Implications of cross-reactivity between penicillins and cephalosporins).
For patients who have had a severe immediate1 hypersensitivity reaction to a penicillin in whom cefazolin is not used, or for patients who have had a severe delayed2 hypersensitivity reaction to a penicillin, use:
clindamycin 600 mg (child: 15 mg/kg up to 600 mg) intravenously, 8-hourly3. See below for modification and duration of therapy. clindamycin clindamycin clindamycin
Consider adding metronidazole to clindamycin because of increasing resistance to clindamycin in gram-negative anaerobes (especially Bacteroides species); add:
metronidazole 500 mg (child: 12.5 mg/kg up to 500 mg) intravenously, 12-hourly. See below for modification and duration of therapy. metronidazole metronidazole metronidazole
If the patient is at increased risk of methicillin-resistant Staphylococcus aureus (MRSA), or is not improving with initial antibiotic therapy and adequate surgical drainage (if indicated), consider adding empirical therapy for MRSAShariati, 2020; add:
vancomycin intravenously; for initial dosing, see Intermittent vancomycin dosing for noncritically ill adults or Intermittent vancomycin dosing for young infants and children. vancomycin vancomycin vancomycin
Modification and duration of therapy: If MRSA is not subsequently identified by culture, consider stopping additional therapy for MRSA. If MRSA is identified, modify therapy based on susceptibility results.
Seek expert advice for ongoing management, timing of switch to oral therapy and duration of therapy. Treatment for 4 to 6 weeks (intravenous + oral) may be requiredMcMullan, 2016.