|Manufacturer:||Merck & Co., Inc.|
Elderly patients being treated for urinary tract infections who have a creatinine clearance of greater than 30 mL/min/1.73 m2 should receive the dosages recommended under Normal Renal Function.Elderly patients being treated for urinary tract infections who have a creatinine clearance of 30 mL/min/1.73 m2 or less should receive 400 mg once daily as recommended under Renal Impairment.
Tendinopathy and Tendon Rupture: Fluoroquinolones, including NOROXIN, are associated with an increased risk of tendinitis and tendon rupture in all ages.
This adverse reaction most frequently involves the Achilles tendon, and rupture of the Achilles tendon may require surgical repair.
Tendinitis and tendon rupture in the rotator cuff (the shoulder), the hand, the biceps, the thumb, and other tendon sites have also been reported.
The risk of developing fluoroquinolone-associated tendinitis and tendon rupture is further increased in older patients usually over 60 years of age, in patients taking corticosteroid drugs, and in patients with kidney, heart or lung transplants.
Factors, in addition to age and corticosteroid use, that may independently increase the risk of tendon rupture include strenuous physical activity, renal failure, and previous tendon disorders such as rheumatoid arthritis.
Tendinitis and tendon rupture have also occurred in patients taking fluoroquinolones who do not have the above risk factors.
Tendon rupture can occur during or after completion of therapy; cases occurring up to several months after completion of therapy have been reported.
NOROXIN should be discontinued if the patient experiences pain, swelling, inflammation or rupture of a tendon.
Patients should be advised to rest at the first sign of tendinitis or tendon rupture, and to contact their healthcare provider regarding changing to a non-quinolone antimicrobial drug.Safety in Children, Adolescents, Nursing mothers, and during Pregnancy: THE SAFETY AND EFFICACY OF ORAL NORFLOXACIN IN PEDIATRIC PATIENTS, ADOLESCENTS (UNDER THE AGE OF 18), PREGNANT WOMEN, AND NURSING MOTHERS HAVE NOT BEEN ESTABLISHED (See PRECAUTIONS, Pediatric Use, Pregnancy, and Nursing Mothers subsections).
The oral administration of single doses of norfloxacin, 6 times Based on a patient weight of 50 kg.
the recommended human clinical dose (on a mg/kg basis), caused lameness in immature dogs.
Histologic examination of the weight-bearing joints of these dogs revealed permanent lesions of the cartilage.
Other quinolones also produced erosions of the cartilage in weight-bearing joints and other signs of arthropathy in immature animals of various species (see ANIMAL PHARMACOLOGY).Seizures: Convulsions have been reported in patients receiving norfloxacin.
Convulsions, increased intracranial pressure, and toxic psychoses have been reported in patients receiving drugs in this class.
Quinolones may also cause central nervous system (CNS) stimulation which may lead to tremors, restlessness, lightheadedness, confusion, and hallucinations.
If these reactions occur in patients receiving norfloxacin, the drug should be discontinued and appropriate measures instituted.The effects of norfloxacin on brain function or on the electrical activity of the brain have not been tested.
Therefore, until more information becomes available, norfloxacin, like all other quinolones, should be used with caution in patients with known or suspected CNS disorders, such as severe cerebral arteriosclerosis, epilepsy, and other factors which predispose to seizures.
(See ADVERSE REACTIONS.)Hypersensitivity Reactions: Serious and occasionally fatal hypersensitivity (anaphylactic) reactions, some following the first dose, have been reported in patients receiving quinolone therapy, including NOROXIN.
Some reactions were accompanied by cardiovascular collapse, loss of consciousness, tingling, pharyngeal or facial edema, dyspnea, urticaria and itching.
Only a few patients had a history of hypersensitivity reactions.
If an allergic reaction to norfloxacin occurs, discontinue the drug.
Serious acute hypersensitivity reactions require immediate emergency treatment with epinephrine.
Oxygen, intravenous fluids, antihistamines, corticosteroids, pressor amines, and airway management, including intubation, should be administered as indicated.Other serious and sometimes fatal events, some due to hypersensitivity, and some due to uncertain etiology, have been reported rarely in patients receiving therapy with quinolones, including NOROXIN.
These events may be severe and generally occur following the administration of multiple doses.
Clinical manifestations may include one or more of the following:fever, rash or severe dermatologic reactions (e.g., toxic epidermal necrolysis, Stevens-Johnson syndrome);vasculitis; arthralgia; myalgia; serum sickness;allergic pneumonitis;interstitial nephritis; acute renal insufficiency or failure;hepatitis; jaundice; acute hepatic necrosis or failure;anemia, including hemolytic and aplastic; thrombocytopenia, including thrombotic thrombocytopenic purpura; leukopenia; agranulocytosis; pancytopenia; and/or other hematologic abnormalities.The drug should be discontinued immediately at the first appearance of a skin rash, jaundice, or any other sign of hypersensitivity, and supportive measures should be instituted (see PRECAUTIONS, Information for Patients and ADVERSE REACTIONS).Clostridium difficile associated diarrhea: Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including NOROXIN, and may range in severity from mild diarrhea to fatal colitis.
Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C.
difficile produces toxins A and B which contribute to the development of CDAD.Hypertoxin producing strains of C.
difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy.
CDAD must be considered in all patients who present with diarrhea following antibiotic use.
Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C.
difficile may need to be discontinued.
Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C.
difficile, and surgical evaluation should be instituted as clinically indicated.Peripheral neuropathy: Rare cases of sensory or sensorimotor axonal polyneuropathy affecting small and/or large axons resulting in paresthesias, hypoesthesias, dysesthesias and weakness have been reported in patients receiving quinolones, including norfloxacin.
Norfloxacin should be discontinued if the patient experiences symptoms of neuropathy including pain, burning, tingling, numbness, and/or weakness, or is found to have deficits in light touch, pain, temperature, position sense, vibratory sensation, and/or motor strength in order to prevent the development of an irreversible condition.Syphilis treatment: Norfloxacin has not been shown to be effective in the treatment of syphilis.
Antimicrobial agents used in high doses for short periods of time to treat gonorrhea may mask or delay the symptoms of incubating syphilis.
All patients with gonorrhea should have a serologic test for syphilis at the time of diagnosis.Patients treated with norfloxacin should have a follow-up serologic test for syphilis after three months.