Modification and duration of therapy for orbital (postseptal) cellulitis

Modify therapy based on the results of culture and susceptibility testing, if possible.

Some patients with orbital (postseptal) cellulitis will be critically ill or have meningitis. To ensure adequate drug exposure in these patients, modified dosages of ceftriaxone, cefotaxime, flucloxacillin and ciprofloxacin are recommended. This is because pharmacokinetics may be altered in critical illness (eg because of enhanced kidney clearance or changes in volume of distribution). Once the critical illness or meningitis has resolved, consider switching to the standard dosage.

Switch to oral therapy when the patient is clinically improving – see Guidance for intravenous to oral switch. The total duration of therapy (intravenous + oral) for orbital cellulitis is 10 to 14 days.

Select oral antibiotic therapy according to the results of culture and susceptibility testing, if possible. If culture and susceptibility test results are not available, use:

For patients who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin, who tolerated initial intravenous therapy with ceftriaxone or cefotaxime, use cefuroxime at the dosage above.

For patients in whom a suitable formulation of cefuroxime is not available, trimethoprim+sulfamethoxazole may be a suitable alternative (see below).

For patients with orbital cellulitis who have had a severe immediate² hypersensitivity reaction to a penicillin in whom ceftriaxone or cefotaxime was not used nor tolerated, for patients who have had a severe delayed³ hypersensitivity reaction to a penicillin and for patients at increased risk of methicillin-resistant Staphylococcus aureus (MRSA) infection, use: