Is it recommended to discontinue antibiotics (abx) if a urine culture is negative?

Discontinuing Antibiotics When Urine Culture is Negative

Yes, antibiotics should be discontinued when the urine culture is negative, provided the patient is clinically well or improving and all other bacterial cultures are negative at 24-36 hours. This is a strong recommendation supported by multiple high-quality pediatric guidelines and represents a critical antimicrobial stewardship opportunity. 1

Clinical Decision Algorithm

For Febrile Infants (8-60 days old)

Discontinue antibiotics when ALL of the following criteria are met: 1

• All bacterial cultures (including urine) are negative at 24-36 hours
• Infant is clinically well or improving (e.g., afebrile, feeding well)
• No other infection requiring treatment exists (e.g., otitis media)

Key timing consideration: While 5-15% of pathogens may grow after 24 hours, this drops to <5% after 36 hours, making 24-36 hours the optimal window for reassessment. 1

For Pediatric Oncology/Neutropenic Patients

Different criteria apply for high-risk febrile neutropenia: 1

• Discontinue empirical antibiotics when blood cultures are negative at 48 hours, patient has been afebrile for ≥24 hours, AND there is evidence of marrow recovery
• For low-risk febrile neutropenia, consider discontinuation at 72 hours even without marrow recovery if cultures are negative and patient has been afebrile ≥24 hours with careful follow-up

For General Adult/Pediatric Populations

The evidence strongly supports discontinuation when: 2, 3

• Urine culture is definitively negative
• Patient is clinically stable or improving
• No alternative source of infection identified

Benefits of Discontinuation

Antimicrobial stewardship benefits include: 1

• Limits unnecessary antibiotic exposure and associated costs
• Reduces disruption to the developing microbiome (particularly important in infants)
• Decreases risk of adverse drug reactions
• Prevents development of antimicrobial resistance
• Avoids complications from prolonged IV access (infiltration, infection)

A quality improvement study demonstrated that implementing systematic urine culture follow-up avoided 3,429 antibiotic days (40% of total prescribed) with no patients developing UTI within 14 days after discontinuation. 2

Critical Pitfalls to Avoid

Do not continue antibiotics based solely on: 1

• Persistent fever in a clinically stable patient (fever alone is not an indication to continue or escalate therapy)
• "Completing the course" when cultures are negative
• Concern about the 5-15% of pathogens that grow after 24 hours (this risk is acceptable given the harms of unnecessary antibiotics) 1

Common scenario requiring caution: Patients with indwelling urinary catheters frequently have positive cultures representing colonization rather than infection. Unnecessary antibiotic prescribing is particularly common in this population, with one study showing concordance between expert opinion and prescriber decisions in only 40% of cases with positive cultures. 4

Implementation Strategy

Establish a systematic follow-up process: 2, 3

• Pharmacist-driven or nurse-driven protocols for routine culture review
• Direct patient contact to discontinue antibiotics when cultures are negative
• Documentation in the electronic medical record
• One health system increased antibiotic discontinuation rates from 4% to 84% using this approach 2

For emergency department settings: A pharmacist-driven follow-up process successfully increased cases reviewed from 0% to 96.7% and patients contacted for discontinuation from 0% to 40%. 3

Special Considerations

If urine culture cannot be obtained (e.g., patient cannot provide sample): Consider empiric treatment or watchful waiting rather than catheterization, as the risks of catheter-associated complications may outweigh benefits. 5

Negative dipstick testing: There is evidence that canceling urine cultures when dipstick is negative (negative leukocyte esterase and nitrite) is safe and prevents overuse of cultures. 5

Pregnancy and recurrent UTIs: These populations may require targeted treatment based on culture results rather than empiric therapy, but the same principle applies—discontinue if cultures are negative and patient is clinically well. 6