Description

Ofloxacin is a synthetic, broad-spectrum antibiotic that belongs to the fluoroquinolone class of drugs. It is a bactericidal agent, meaning it kills bacteria rather than just inhibiting their growth. It is available in various forms, including oral tablets, eye drops, and ear drops.

Indications

Ofloxacin is used to treat a wide range of bacterial infections caused by susceptible organisms. Its use for some infections, like gonorrhea, is no longer recommended due to widespread bacterial resistance. It is often reserved for infections where other, safer antibiotics are not suitable. Common indications for ofloxacin include:

• Respiratory tract infections: Bronchitis and pneumonia.

• Urinary tract infections (UTIs): Uncomplicated and complicated UTIs, including cystitis and prostatitis.

• Skin and soft tissue infections.

• Sexually transmitted diseases: Chlamydia and certain types of cervicitis and urethritis.

• Eye infections: Bacterial conjunctivitis and corneal ulcers (as ophthalmic drops).

• Ear infections: Otitis externa and chronic suppurative otitis media with a perforated eardrum (as otic drops)
• Mechanism of Action

Ofloxacin’s mechanism of action is based on its ability to interfere with bacterial DNA replication, transcription, and repair. It achieves this by inhibiting two key bacterial enzymes:

1. DNA Gyrase (Topoisomerase II): This enzyme is essential for the supercoiling and unwinding of bacterial DNA. DNA gyrase relaxes the supercoiled DNA, a necessary step for replication. Ofloxacin binds to the DNA-gyrase complex, stabilizing it in a state that prevents the enzyme from functioning. This halts the replication process and leads to the accumulation of DNA breaks.
2. Topoisomerase IV: This enzyme is crucial for the final stages of bacterial cell division, as it separates the replicated daughter chromosomes. Ofloxacin similarly inhibits this enzyme, preventing the successful segregation of DNA strands.

By inhibiting both of these essential enzymes, ofloxacin disrupts bacterial cell division and ultimately causes bacterial cell death. A significant aspect of its effectiveness is its selective toxicity; ofloxacin has a much higher affinity for these bacterial enzymes than for the analogous enzymes in human cells (e.g., human topoisomerase II), which minimizes harm to the patient’s own cells.