Question

A woman presenting with symptoms of urinary tract infection was prescribed a drug that causes tendon rupture and arthropathy. What is the mechanism of action of the drug?

• A. DNA gyrase inhibition
• B. Ribosomal inhibition
• C. Cell wall synthesis
• D. Inhibition of folic acid synthesis

Answer 1

The Correct Option is A

This question relates to the mechanism of action of a drug commonly used to treat urinary tract infections (UTIs). The symptoms described and the adverse effects such as tendon rupture and arthropathy suggest the use of a particular class of antibacterial drugs known as fluoroquinolones.

Fluoroquinolones, such as ciprofloxacin, are antibiotics that treat a variety of infections, including UTIs. These drugs are known for their distinctive side effects like tendon damage and joint issues. The key mechanism by which these drugs exert their antibacterial effect is through DNA gyrase inhibition.

DNA Gyrase Inhibition Explained:

• Target Enzyme: DNA gyrase is an essential enzyme in bacteria that introduces negative supercoils into DNA. This is crucial for DNA replication and transcription because it alleviates the torsional stress that develops ahead of the replication fork.
• Action: By inhibiting DNA gyrase, fluoroquinolones disrupt the replication of bacterial DNA. This prevents bacterial cells from properly synthesizing DNA, thereby halting bacterial proliferation and leading to cell death.

Given the options, the correct mechanism of action for the drug causing tendon rupture and arthropathy in this scenario is DNA gyrase inhibition.