

Chronic Rhinosinusitis
- Refer to Otolaryngology.
- Antimicrobials alone are often not effective.
Pathogens
- Common: anaerobes, streptococci, S. aureus
- Other: Gram-negative bacilli, P. aeruginosa
Drug Treatment
- Duration: Usually at least 14 days.
Organisms with decreased penicillin susceptibility
Consult Infection Diseases/Clinical Microbiology
Empiric
Penicillin allergy
- Avoid in pregnancy and breastfeeding.
- Metabolised by unknown pathways. (fe = 0.4).
OR
Pathogens Known
P. aeruginosa
- fe = 0.5, consider adjusting dose if CrCl reduced.
- Inhibits CYP1A2 (strong) and 3A.
- Subject to OAT and OATP (transporter) inhibition.
- Avoid in pregnancy and breastfeeding.
S. aureus
- fe = 0.7, consider adjusting dose if CrCl reduced.
- Risk of hepatotoxicity is increased in females, patients > 55 years old, high doses, and courses longer than 14 days duration.
Topic Code: 99227