Side-effects of Norfloxacin

Norfloxacin (Noroxin) was synthesized at the Kyorin Central Research Laboratory in Japan. It is a fluorinated quinolone carboxylic acid derivative with a molecular weight of 319.34 and has the chemical formula 1-ethyl-6-fluoro-1,4-dihydro-4- oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid. Its empirical formula is C16H18FN3O3. 

Norfloxacin is available in 400-mg tablets. Norfloxacin inhibits bacterial DNA synthesis and is bactericidal. The antibacterial spectrum of norfloxacin is very similar to that of enoxacin, but generally the drug is less active than ciprofloxacin and other newer fluoroquinolones. Since the distribution of norfloxacin is more limited than that of ciprofloxacin, it is used primarily to treat infections associated with the gastrointestinal or genitourinary systems.

Mechanism of action

Similar to other fluoroquinolones, norfloxacillin is a DNA gyrase inhibitor; it inhibits bacterial DNA synthesis and is bactericidal.

Uses

Norfloxacin is used to treat a variety of bacterial infections. This medication belongs to a class of drugs known as quinolone antibiotics. It works by stopping the growth of bacteria.This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.

Bioavailability

After oral administration, 30–40% of the norfloxacin dose is rapidly absorbed, and peak serum levels occur in 1–2 h. The serum half-life of norfloxacin is 3.75 h. Overall, norfloxacin is absorbed slightly more slowly than ciprofloxacin and ofloxacin. Absorption is only slightly delayed if the drug is given with food rather than in the fasting state. However, the absorption of norfloxacin is significantly reduced when it is given with milk or yoghurt, with mean peak serum concentrations of 50–60% of those achieved when norfloxacin is given with water. The presence of acute diarrhea does not significantly alter the pharmacokinetics of norfloxacin, except that the time to peak serum concentrations is delayed. Other parameters, such as the peak serum concentration, total area under the serum concentration curve (AUC), serum half-life, and rate of elimination, are similar to that found when intestinal function is normal.

Side-effects

The side-effects reported with norfloxacin are similar to, or fewer than, those described for ciprofloxacin and other fluoroquinolones. Overall, norfloxacin is relatively safe, with the rate of adverse events being only about 3%. Nausea, headache, dizziness, rash, elevation of liver enzymes, and eosinophilia are the most commonly reported adverse effects. Among neutropenic patients given norfloxacin prophylaxis, the rate of adverse effects was 5.5%, which is less than with other agents used for this purpose.