Intravenous antibiotic regimens for acute pyelonephritis in nonpregnant adults

For the treatment of adults with sepsis or septic shock, see Sepsis and septic shock from a urinary tract source in adults.

For the treatment of pyelonephritis in pregnant patients, see Acute pyelonephritis in pregnancy.

See Approach to empirical antibiotic choice for UTI in adults and Rationale for intravenous antibiotic therapy for acute pyelonephritis in nonpregnant adults for a discussion of antibiotic choice.

For empirical intravenous therapy for acute pyelonephritis in nonpregnant adults, while awaiting the results of investigations, useBonkat, 2024Elbaz, 2020:

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

Ceftriaxone may be used for patients in whom intravenous therapy is likely to continue for 72 hours or longer1, to avoid the need to switch to a non–aminoglycoside-containing regimen at 72 hours. Ceftriaxone is also recommended if the patient has contraindications or precautions that preclude aminoglycoside use. Use:

ceftriaxone 1 g intravenously, daily. See advice on modification and duration of therapy. ceftriaxone ceftriaxone ceftriaxone

For nonpregnant adults who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin, any of the above regimens can be used.

For nonpregnant adults who have had a severe immediate2 hypersensitivity reaction to a penicillin, ceftriaxone (as 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 nonpregnant adults who have had a severe immediate2 hypersensitivity reaction to a penicillin in whom ceftriaxone is not used, or for patients who have had a severe delayed3 hypersensitivity reaction to a penicillin, use gentamicin or tobramycin (as above) and seek expert advice.

For nonpregnant adults managed in an emergency department, short-stay ward or urgent care centre, giving a single dose of an intravenous antibiotic and discharging the patient on oral therapy once clinically improved can be a useful strategy.

1 If the likely duration of intravenous therapy is not known, it is preferable to start with an aminoglycoside regimen (gentamicin or tobramycin) and not delay administration of antibiotics.Return
2 Severe immediate hypersensitivity reactions include anaphylaxis, compromised airway, airway angioedema, hypotension and collapse.Return
3 Severe delayed hypersensitivity reactions include cutaneous adverse drug reactions (eg drug rash with eosinophilia and systemic symptoms [DRESS], Stevens–Johnson syndrome/toxic epidermal necrolysis [SJS/TEN], severe blistering or desquamative rash), and significant internal organ involvement (eg acute interstitial nephritis).Return