Empirical therapy for liver abscess in adults
The empirical antibiotic regimen for liver abscess contains metronidazole to treat potential Entamoeba histolytica infection until the aetiology of the abscess is confirmed.
Patients with liver abscess may rarely have sepsis or septic shock. For patients with sepsis or septic shock, start antibiotic therapy within 1 hour of presentation to medical care or, for ward-based patients, development of sepsis or septic shock. Antibiotics should be administered immediately after blood samples are taken for culture. For nonantibiotic management of sepsis or septic shock, see Resuscitation of patients with sepsis or septic shock.
For empirical therapy of liver abscess in adults, as a 3-drug regimen, use:
1gentamicin intravenously; see Gentamicin initial dose calculator for adults for initial dose. See Principles of aminoglycoside use for prescribing considerations and subsequent dosing. See advice on modification and duration of therapy gentamicin gentamicin gentamicin
OR
1tobramycin intravenously; see Tobramycin initial dose calculator for adults for initial dose. See Principles of aminoglycoside use for prescribing considerations and subsequent dosing. See advice on modification and duration of therapy tobramycin tobramycin tobramycin
PLUS with either of the above drugs
metronidazole 750 mg intravenously, 8-hourly. See advice on modification and duration of therapy metronidazole metronidazole metronidazole
PLUS EITHER
1amoxicillin 2 g intravenously, 6-hourly. For dosage adjustment in adults with kidney impairment, see amoxicillin dosage adjustment. See advice on modification and duration of therapy amoxicillin amoxicillin amoxicillin
OR
1ampicillin 2 g intravenously, 6-hourly. For dosage adjustment in adults with kidney impairment, see ampicillin dosage adjustment. See advice on modification and duration of therapy. ampicillin ampicillin ampicillin
For liver abscess, prolonged intravenous therapy (eg 2 weeks) may be required (see Modification and duration of therapy for liver abscess in adults). A non-aminoglycoside–containing regimen can be used initially if it is preferred, because it avoids the need to switch from an aminoglycoside-containing regimen at 72 hours if susceptibility results are not available. Non-aminoglycoside–containing regimens are also used if gentamicin or tobramycin is contraindicated or for adults who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin, use:
ceftriaxone 2 g intravenously, daily. For adults with septic shock or requiring intensive care support, use 1 g intravenously, 12-hourly1. See advice on modification and duration of therapy ceftriaxone ceftriaxone ceftriaxone
PLUS
metronidazole 750 mg intravenously, 8-hourly. See advice on modification and duration of therapy. metronidazole metronidazole metronidazole
For adults who have had a severe immediate2 hypersensitivity reaction to a penicillin, ceftriaxone plus metronidazole (at the dosages above) can be considered if a beta-lactam antibiotic is strongly preferred (for considerations, see Severe immediate hypersensitivity: Implications of cross-reactivity between penicillins and cephalosporins).
For adults who have had a severe immediate2 hypersensitivity reaction to a penicillin in whom ceftriaxone plus metronidazole is not used, or for adults who have had a severe delayed3 hypersensitivity reaction to a penicillin, seek expert advice – treatment options include metronidazole in combination with either gentamicin, tobramycin, ciprofloxacin or aztreonam.