Description

Ciprofloxacin is a broad-spectrum antibiotic belonging to the fluoroquinolone class. It is a bactericidal agent, meaning it kills bacteria directly. It is available in various forms, including tablets, oral suspension, and intravenous (IV) solutions, as well as topical formulations like eye and ear drops. Ciprofloxacin is effective against a wide range of bacteria, particularly Gram-negative bacteria such as E. coli, Pseudomonas aeruginosa, and Salmonella. Due to the risk of serious and potentially irreversible side effects, ciprofloxacin and other fluoroquinolones are typically reserved for infections where other antibiotics are not suitable.

Indications

Ciprofloxacin is used to treat a variety of bacterial infections, especially those that are severe or complicated. Its indications include:

• Urinary Tract Infections (UTIs): Including complicated UTIs, acute uncomplicated cystitis, and pyelonephritis (kidney infection).

• Respiratory Tract Infections: Such as pneumonia and acute exacerbations of chronic bronchitis.

• Gastrointestinal Infections: Including infectious diarrhea and typhoid fever.

• Bone and Joint Infections: Such as osteomyelitis.

• Skin and Soft Tissue Infections: For a variety of uncomplicated infections.

• Anthrax: Ciprofloxacin is used to treat and prevent anthrax infection after inhalational exposure.

• Plague: It is also used to treat and prevent plague.

• Gonorrhea: It is a treatment option for uncomplicated gonorrhea, although resistance has led to other antibiotics being preferred in many cases.

• Intra-abdominal Infections: Often used in combination with other antibiotics to treat complicated intra-abdominal infections.

Mechanism of Action

Ciprofloxacin works by inhibiting the function of two essential bacterial enzymes, DNA gyrase and topoisomerase IV, which are critical for DNA replication, transcription, and repair. This unique mechanism is different from that of beta-lactam antibiotics. The key steps are:

1. Inhibition of DNA Gyrase: DNA gyrase is an enzyme that introduces negative supercoils into bacterial DNA, which is necessary to relieve torsional stress during DNA replication and transcription. Ciprofloxacin binds to and inhibits this enzyme, preventing DNA from unwinding and leading to its damage.

2. Inhibition of Topoisomerase IV: Topoisomerase IV is an enzyme responsible for separating intertwined daughter DNA strands after replication. Ciprofloxacin also inhibits this enzyme, which prevents the final separation of the new bacterial DNA, thus blocking cell division.

3. Bactericidal Effect: By disrupting these essential processes of DNA replication and repair, ciprofloxacin effectively halts the bacterium’s ability to multiply and function, leading to DNA fragmentation and rapid cell death. This makes it a highly effective bactericidal agent.