Noroxin (norfloxacin) is a broad-spectrum fluoroquinolone antibiotic indicated for the treatment of complicated and uncomplicated urinary tract infections caused by susceptible strains of designated microorganisms. As a second-generation quinolone, it demonstrates high bioavailability and concentration-dependent bactericidal activity against both Gram-negative and Gram-positive pathogens. Its mechanism involves inhibition of bacterial DNA gyrase and topoisomerase IV, effectively disrupting DNA replication and transcription. Clinicians value Noroxin for its reliable efficacy in cases where first-line agents may be insufficient due to emerging resistance patterns.

Features

• Active ingredient: Norfloxacin 400mg
• Pharmaceutical form: Film-coated tablets
• Mechanism: DNA gyrase and topoisomerase IV inhibition
• Spectrum: Broad activity against Gram-negative and Gram-positive bacteria
• Pharmacokinetics: Approximately 30-40% oral bioavailability
• Half-life: 3-4 hours in patients with normal renal function
• Excretion: Primarily renal (approximately 30% unchanged)

Benefits

• Rapid bactericidal action against common uropathogens including E. coli, Klebsiella pneumoniae, and Proteus mirabilis
• High urinary concentration exceeding MIC values for most susceptible organisms
• Effective against β-lactamase producing strains
• Convenient twice-daily dosing regimen supports adherence
• Demonstrated efficacy in prostatitis caused by susceptible organisms
• Reduced treatment duration compared to some alternative regimens

Common use

Noroxin is primarily prescribed for the treatment of complicated and uncomplicated urinary tract infections, including cystitis and pyelonephritis, caused by susceptible strains of Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Proteus mirabilis, Pseudomonas aeruginosa, Citrobacter freundii, Staphylococcus aureus, and group D streptococci. It is also indicated for sexually transmitted infections such as uncomplicated urethral and cervical gonorrhea caused by Neisseria gonorrhoeae. Off-label uses may include infectious diarrhea caused by susceptible Campylobacter jejuni, Shigella species, or invasive Salmonella species, though culture and susceptibility testing should guide therapy.

Dosage and direction

The recommended adult dosage for uncomplicated urinary tract infections is 400mg orally twice daily for 3 days. For complicated urinary tract infections, the dosage is 400mg twice daily for 7-10 days. For gonorrhea, a single 800mg dose is administered. Dosage adjustment is required in patients with renal impairment: for creatinine clearance 30mL/min/1.73m² or greater, no adjustment is needed; for clearance between 10-29mL/min/1.73m², administer 400mg once daily; for clearance less than 10mL/min/1.73m², avoid use unless benefits outweigh risks. Tablets should be taken with a full glass of water, one hour before or two hours after meals. Patients should maintain adequate hydration during therapy.

Precautions

Noroxin should be used with caution in patients with known or suspected central nervous system disorders that may predispose to seizures or lower the seizure threshold. Patients should be advised that dizziness or lightheadedness may occur and to avoid driving or operating machinery if these symptoms develop. Tendon inflammation or rupture may occur during or after therapy, particularly in elderly patients, those receiving concomitant corticosteroids, and those with renal impairment or solid organ transplants. Photosensitivity reactions may occur; patients should avoid excessive sunlight or artificial UV light and use protective measures. Blood glucose disturbances, including both hypoglycemia and hyperglycemia, have been reported, particularly in diabetic patients receiving oral hypoglycemic agents or insulin.

Contraindications

Noroxin is contraindicated in patients with known hypersensitivity to norfloxacin, other quinolones, or any component of the formulation. It should not be used in patients with a history of tendon disorders related to fluoroquinolone administration. Concomitant administration with tizanidine is contraindicated due to the risk of potentiated hypotensive and sedative effects. Use is contraindicated in patients with known QTc prolongation, uncorrected hypokalemia, or those taking medications that prolong the QTc interval. The drug is contraindicated in children and adolescents under 18 years of age due to potential effects on developing cartilage.

Possible side effect

Common adverse reactions (≥1%) include nausea, headache, dizziness, fatigue, and abdominal pain. Less frequent reactions (0.1-1%) comprise photosensitivity, rash, pruritus, vomiting, diarrhea, and taste disturbance. Serious adverse effects include tendonitis and tendon rupture (particularly Achilles tendon), peripheral neuropathy, central nervous system effects (seizures, increased intracranial pressure, psychosis), QTc prolongation and ventricular arrhythmias, hepatotoxicity, and Clostridium difficile-associated diarrhea. Hematologic abnormalities including leukopenia, neutropenia, and anemia may occur. Musculoskeletal effects in pediatric patients and cartilage damage in weight-bearing joints have been observed in animal studies.

Drug interaction

Noroxin interacts significantly with multivalent cation-containing products; administer at least 2 hours before or 6 hours after antacids containing magnesium or aluminum, sucralfate, metal cations such as iron, or zinc-containing products. Concurrent use with drugs that prolong QTc interval (antiarrhythmics, antipsychotics, antidepressants, macrolides) may increase risk of torsades de pointes. Norfloxacin may enhance effects of warfarin; monitor INR closely. Concomitant use with corticosteroids may increase risk of tendon rupture. Theophylline levels may increase; monitor and adjust dosage accordingly. Norfloxacin may enhance effects of oral hypoglycemics; monitor blood glucose. Probenecid decreases renal secretion of norfloxacin.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, skip the missed dose and resume the regular dosing schedule. Do not double the dose to make up for a missed administration. Maintaining consistent antibiotic levels is important for efficacy, but single missed doses generally do not significantly impact overall treatment outcomes if the regimen is promptly resumed. Patients should be instructed to contact their healthcare provider if multiple doses are missed or if uncertainty exists about how to proceed.

Overdose

Symptoms of overdose may include nausea, vomiting, diarrhea, dizziness, headache, tremors, seizures, and mental status changes. ECG monitoring is recommended due to potential QTc prolongation. Management is primarily supportive with careful observation and symptomatic treatment. Hemodialysis removes approximately 10% of the drug and may be considered in severe cases, though its clinical benefit is limited. Gastric lavage may be considered if performed soon after ingestion. Maintain adequate hydration and monitor renal function. Specific antidotes are not available. Seizures should be managed with standard anticonvulsant therapy, avoiding drugs that may prolong QTc interval.

Storage

Store at controlled room temperature between 15-30°C (59-86°F). Protect from light and moisture. Keep in the original container with the lid tightly closed. Do not store in bathroom cabinets where humidity levels may fluctuate. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging. Properly discard any unused medication after completion of therapy or if treatment is discontinued. Do not flush medications down the toilet or pour into drains unless instructed to do so.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Noroxin is a prescription medication that should be used only under the supervision of a qualified healthcare professional. The prescribing physician should be consulted for diagnosis and treatment decisions. Individual patient factors including renal function, concomitant medications, and specific pathogen susceptibility must be considered when prescribing this medication. Serious adverse reactions including tendon rupture, peripheral neuropathy, and central nervous system effects may occur. Not all possible uses, precautions, side effects, or interactions are listed here.

Reviews

Clinical studies demonstrate norfloxacin’s efficacy in urinary tract infections with clinical success rates of 85-95% in susceptible infections. Many urologists report reliable performance in complicated cases, though increasing resistance patterns have diminished its first-line status in some regions. Patients generally tolerate the medication well, though some report gastrointestinal discomfort. The twice-daily dosing is viewed favorably compared to more frequent regimens. Post-marketing surveillance continues to monitor for rare but serious adverse events. Many infectious disease specialists reserve norfloxacin for cases where susceptibility is confirmed or when alternative agents are not suitable.