Active Ingredients: Norfloxacin
The overall rate of adverse events in patients treated with fluoroquinolones is roughly similar to that seen in patients treated with other antibiotic classes. Centers for Disease Control study found patients treated with fluoroquinolones experienced adverse events severe enough to lead to an emergency department visit more frequently than those treated with cephalosporins or macrolides, but less frequently than those treated with penicillins, clindamycin, sulfonamides, or vancomycin.
Among these, tendon problems and exacerbation of the symptoms of the neurological disorder myasthenia gravis are the subject of "black box" warnings in the United States.
Younger people typically experience good recovery, but permanent disability is possible, and is more likely in older patients. Simultaneous use of corticosteroids is present in almost one-third of quinolone-associated tendon rupture.
Fluoroquinoline treatment is associated with risk that is similar to or less than that associated with broad spectrum cephalosporins. Therefore, cyclosporine serum levels should be monitored and appropriate cyclosporine dosage adjustments made when these drugs are used concomitantly.
Medications Some quinolones exert an inhibitory effect on the cytochrome P-450 system, thereby reducing theophylline clearance and increasing theophylline blood levels. Additionally other fluoroquinolones, especially enoxacin, and to a lesser extent ciprofloxacin and pefloxacin, also inhibit the metabolic clearance of theophylline.
As such, these drug interactions involving the fluoroquinolones appear to be drug specific rather than a class effect. The fluoroquinolones have also been shown to interfere with the metabolism of caffeine and the absorption of levothyroxine.
The usual dose is one 400 mg tablet, taken twice a day.
Swallow the tablet with a drink of water. This is because your body absorbs less norfloxacin after a meal, which means the medicine is less effective. Try to space out the doses over the day - so ideally, take a dose every 12 hours.