norfloksasiini

Norfloksasiini, also known as norfloxacin, is a synthetic antibacterial agent in the fluoroquinolone class. It was developed to treat a range of bacterial infections and remains in use in some regions, though its role has declined in others due to safety concerns and rising resistance.

Mechanism of action: Norfloxacin inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, enzymes essential for DNA replication and transcription. This interference prevents bacterial growth and helps to clear infections when the drug is active against the infecting organism.

Spectrum and indications: Its activity covers many Gram-negative bacteria, including Escherichia coli, Klebsiella species, and Proteus species, with activity against some Gram-positive organisms such as Staphylococcus aureus. It is commonly used for uncomplicated urinary tract infections, cystitis, prostatitis, and certain gynecological infections, and has been used for gonorrhea. Its broader use for pneumonia or intra-abdominal infections has diminished due to resistance and safety considerations.

Pharmacokinetics: Norfloxacin is administered orally and has moderate bioavailability (about 30-40%), with absorption reduced by food or dairy products. Peak plasma concentrations are reached within 1–2 hours. It is primarily eliminated by the kidneys, with a plasma half-life of about 4 hours, requiring dose adjustments in renal impairment.

Adverse effects and safety: Common adverse effects include nausea, diarrhea, and abdominal discomfort. Serious risks associated with fluoroquinolones include tendonitis and tendon rupture, peripheral neuropathy, central nervous system effects, QT interval prolongation, and photosensitivity. It is generally avoided in children and during pregnancy or breastfeeding due to potential cartilage damage and other risks.

Cautions: Avoid concomitant use with polyvalent cations (such as aluminum, magnesium, iron, or zinc-containing products) and separate dosing accordingly. Resistance is a concern with widespread use, so guidelines advocate cautious, targeted use based on local susceptibility patterns.