Acute appendicitis

• Blood cultures prior to starting antibiotics.
• Intra-operative or percutaneous drainage samples (if applicable)

Amoxicillin 1g every 8 hours IV

AND

Gentamicin (use NHS Lothian Calculator located AMT intranet page)

AND

Metronidazole 400mg every 8 hours orally (500mg every 8 hours IV if oral route unavailable)

Penicillin allergy or known MRSA carriage:

Vancomycin IV (use NHS Lothian Calculator located AMT intranet page) - target trough level 10-15mg/L

AND

Gentamicin (use NHS Lothian Calculator located AMT intranet page)

AND

Metronidazole 400mg every 8 hours orally(500mg every 8 hours IV if oral route unavailable)

• Review IV antibiotics within 48 hours OR as soon as imaging results available
• In the absence of complications, consider early IV to oral switch

Preferred:

Co-trimoxazole 960mg every 12 hours orally

PLUS

Metronidazole 400mg every 8 hours orally

Alternative:

Co-amoxiclav 625mg every 8 hours orally (Suitable for those ≤ 65 years old with a low risk of C.diff infection.

See Prevention, diagnosis and management of CDI.) Recommended total duration

• Uncomplicated infection with adequate source control: no antibiotics required post-operatively
• Uncomplicated infection managed without surgical intervention: 5 days total (IV + PO)
• Complicated infection with adequate source control: 5 days total (IV + PO) post source control

Longer courses may be required for complex patients and abscess not amenable to drainage. Please discuss with microbiology