Deep Neck Space Infections

• These include peritonsillar abscess, Ludwig’s angina (submandibular space infection), parapharyngeal and retropharyngeal space infections.
• Infections are typically polymicrobial.
• Refer to Otolaryngology.

Pathogens

• Common: S. pyogenes, Viridans Streptococci, Peptostreptococcus
• Other: Actinomyces, Fusobacterium necrophorum, Aggregatabacter (Actinobacillus), Eikenella

Drug Treatment

• Duration: At least 10 days. Actinomyces infections require very prolonged therapy – consult Infectious Diseases/Clinical Microbiology.

Empiric

amoxicillin+clavulanic acid HMLSchedNZFPMLnoids Amoxicillin+Clavulanic Acid F: 0.9 / 0.5 Half life: 2 hours / 1 hour Elimination: renal fe: 0.9 / 0.5

IV 1 g/200 mg every eight hours

• fe (amoxicillin) = 0.9, fe (clavulanic acid) = 0.5, consider adjusting dose if CrCl reduced.

Mild penicillin allergy

ceftriaxone HMLSchedNZFPMLnoids Ceftriaxone F: n/a Half life: 8 hours Elimination: 50% renal and 50% biliary excretion fe: 0.5

IV 2 g every 24 hours

• fe = 0.5, consider adjusting dose if CrCl reduced.

AND

metronidazole HMLSchedNZFPMLnoids Metronidazole F: 1 Half life: 8 hours Elimination: oxidation, glucuronidation fe: 0.1

IV 500 mg every twelve hours

• High oral availability – prescribe orally unless GI absorption is compromised or patient is nil by mouth.
• Metabolised by unknown pathways. (fe = 0.1).

Severe penicillin allergy

ciprofloxacin HMLSchedNZFPMLnoids Ciprofloxacin F: 0.7 Half life: 4 hours Elimination: renal fe: 0.5 Additional points: Inhibits CYP1A2 and 3A. Antacids, milk, and enteral feeds ↓ absorption.

IV 400 mg every twelve hours

• fe = 0.5, consider adjusting dose if CrCl reduced.
• Inhibits CYP1A2 (strong) and 3A.
• Subject to OAT and OATP (transporter) inhibition.

AND

vancomycin HMLSchedNZFPMLnoids Vancomycin F: n/a Half life: 6 hours Elimination: renal fe: 0.9 Additional points: TDM

See dosing guidelines (use high doses).

• fe = 0.9, adjust dose if CrCl reduced.
• Must be given diluted (1 g in at least 200 mL) and slowly (≤ 1000 mg/hour) to minimise infusion reactions.

AND

• High oral availability – prescribe orally unless GI absorption is compromised or patient is nil by mouth.
• Metabolised by unknown pathways. (fe = 0.1).

Topic Code: 99224

must be prescribed or recommended by a consultant.