What is the first line antibiotic treatment for pyelonephritis?

For the treatment of pyelonephritis, particularly uncomplicated cases, fluoroquinolones like Ciprofloxacin are often considered first-line antibiotics due to their effectiveness against the common causative organisms, such as Escherichia coli. These antibiotics have robust urinary tract penetration and are able to achieve adequate concentrations in the renal tissue, making them suitable for treating infections in the kidneys.

Amoxicillin, while it can be effective for some urinary tract infections, is less commonly used as a first-line treatment for pyelonephritis because it may not cover the resistant strains of bacteria that are frequently responsible for such infections. Doxycycline is generally not a first-line treatment for pyelonephritis either; it is more often used for specific infections like those caused by atypical organisms. Vancomycin is typically reserved for severe infections or when resistant organisms, such as MRSA, are suspected, rather than for uncomplicated pyelonephritis.

Thus, Ciprofloxacin is preferred as it combines effective coverage, good pharmacokinetics for urinary tract infections, and is generally well-tolerated, making it the initial choice for managing pyelonephritis in many clinical guidelines.