Acute Rhinosinusitis

Pathogens

• Common: S. pneumoniae, H. influenzae, viruses
• Other: Moraxella catarrhalis, S. aureus, Gram-negative bacilli, anaerobes

Drug Treatment

• Duration: Usually 5 to 7 days.

Empiric

amoxicillin HMLSchedNZFPMLnoids Amoxicillin F: 0.9 Half life: 2 hours Elimination: renal fe: 0.9

PO 500 mg three times a day

• fe = 0.9, consider adjusting dose if CrCl is reduced.
• Use amoxicillin+clavulanic acid if non-response to 72 hours of amoxicillin treatment.

Penicillin allergy

doxycycline HMLSchedNZFPML Doxazosin F: 0.7 Half life: 12 hours Elimination: CYP3A fe: 0.1

PO 200 mg on day 1 then 100 mg once a day

• Avoid in pregnancy and breastfeeding.
• Metabolised by unknown pathways. (fe = 0.4).

OR

roxithromycin HMLSchedNZFPML Roxithromycin F: 0.8 Half life: 12 hours Elimination: CYP3A fe: 0.1

PO 300 mg once a day

• If pregnant, consider erythromycin instead of roxithromycin as there are less safety in pregnancy data available for roxithromycin.
• Metabolised by and inhibits CYP3A. (fe < 0.1).
• Subject to P-glycoprotein inhibition and induction.

Pathogens Known (or poor response to amoxicillin)

Beta-lactamase producing organisms or anaerobes

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

PO 500 mg/125 mg three times a day

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

S. aureus

flucloxacillin HMLSchedNZFPMLnoids Flucloxacillin F: 0.9 Half life: 1 hour Elimination: renal fe: 0.7

PO 500 mg four times a day

• 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.

S. pneumoniae

• fe = 0.9, consider adjusting dose if CrCl is reduced.

OR

• Avoid in pregnancy and breastfeeding.
• Metabolised by unknown pathways. (fe = 0.4).

Topic Code: 99226

must be prescribed or recommended by a consultant.