Norfloxacin
Indications
Norfloxacin is used for:
Uncomplicated urinary tract infections (including cystitis), Uncomplicated urethral and cervical gonorrhea, Prostatitis, Gastroenteritis
Adult Dose
Prostatitis
Caused by susceptible strains E.coli
400 mg PO q12hr for 28-42 days
UTI (Cystitis)
Uncomplicated, caused by E. coli, K. pneumoniae or P. mirabilis: 400 mg PO q12hr for 3 days
Uncomplicated, caused by other susceptible organisms: 400 mg PO q12hr for 7-10 days
Complicated: 400 mg PO q12hr for 10-21 days
Limitation-of-use: Reserve fluoroquinolones for patients who do not have other available treatment options for uncomplicated urinary tract infections
Gonorrhea
800 mg PO single dose
Uncomplicated urethral and cervical gonorrhea caused by Neisseria gonorrhoeae
Travelers Diarrhea
400 mg PO q12hr for 3 days
Child Dose
<18 years: Safety and efficacy not established
Renal Dose
Renal impairment:
CrCl (ml/min)
<30 400 mg once daily
Administration
Should be taken on an empty stomach. Take on an empty stomach 1 hr before or 2 hr after meals, w/ a glass of water. Ensure adequate hydration. Do not take w/ dairy products.
Contra Indications
Hypersensitivity to quinolones; children <18 yr. Lactation.
Precautions
Patient w/ known prolongation of QT interval, uncorrected hypokalaemia, known or suspected CNS disorders (e.g. severe cerebral arteriosclerosis) or other factors that predispose to seizures. Kidney, heart or lung transplant recipients. Renal impairment. Pregnancy and lactation. Patient Counselling This drug may cause dizziness and lightheadedness, if affected do not drive or operate machinery. Avoid unnecessary or excessive exposure to sunlight or artificial UV light (e.g. tanning beds, UVA/UVB treatment). If staying outdoors is necessary, use protective measures (e.g. sunscreen, wear loose-fitting clothes). Rest and refrain from exercise as it may increase risk of tendon rupture. Monitoring Parameters Periodically monitor CBC, renal and hepatic function during prolonged therapy.
Lactation: Small amounts excreted in breast milk, discontinue drug or do not nurse
Pregnancy-Lactation
Interactions
Additive effect on QT interval prolongation w/ class IA (e.g. quinidine) or class III (e.g. amiodarone) antiarrhythmics and other drugs that prolong QT interval (e.g. erythromycin, TCAs, antipsychotic agents). Increased serum concentrations of theophylline. Reduced absorption w/ oral multivitamins and mineral supplements containing divalent or trivalent cations (e.g. Fe, Zn) and antacids containing Al or Mg, sucralfate, buffered didanosine.
Prolonged prothrombin time w/ concomitant coumarin anticoagulant. Increased risk of severe tendon disorders w/ corticosteroids. Concurrent use w/ NSAIDs may increase the risk of CNS stimulation and convulsive seizures.
Adverse Effects
Side effects of Norfloxacin :
1-10%
Nausea (4%), Dizziness (3%), Headache (3%), Stomach cramps (3%), Weakness (1%)
<1%
Abdominal pain, Anorexia, Anxiety, Arthralgia, Arthritis, Ataxia, Back pain, Bitter taste, Cholestatic jaundice, Confusion, Constipation, Depression, Diarrhea, Diplopia, Dysgeusia, Dyspepsia, Dyspnea, Erythema, Exacerbation of myasthenia gravis, Fever, Flatulence, GI bleeding, Heartburn
Potentially Fatal: Anaphylaxis, acute renal failure, seizures.
Mechanism of Action
Norfloxacin inhibits the action of DNA gyrase in DNA replication, transcription, repair, recombination and transposition.