What two empiric antibiotics should be avoided if there is suspicion of pyelonephritis?

When considering empiric antibiotic treatment for pyelonephritis, it is essential to choose medications that effectively penetrate renal tissue and are active against the likely pathogens, such as E. coli. Macrobid (nitrofurantoin) and fosfomycin are antibiotics that should be avoided in cases of suspected pyelonephritis because they are primarily indicated for uncomplicated urinary tract infections (UTIs) and do not achieve adequate renal tissue concentrations necessary for treating a kidney infection.

Nitrofurantoin is effective for lower urinary tract infections but has limited efficacy against upper tract infections like pyelonephritis. Fosfomycin is also more suited for uncomplicated cystitis. The pathogens involved in pyelonephritis, which can include more resistant strains of bacteria, typically require broader-spectrum coverage that these medications do not provide.

In contrast, other options listed may include antibiotics that can penetrate renal tissue and are better suited for treating pyelonephritis. While they may have their own limitations, they would typically not be avoided as empiric therapies in this context. Thus, choosing to avoid nitrofurantoin and fosfomycin aligns with best practices for effectively addressing pyelonephritis.