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Norbactin

Ranbaxy Nigeria Limited
24, Abimbola street, Abimbola House, Isolo, Lagos.
Tel: 234-1-7932744, 7913002
Fax: 234 1 7913003, 4526371

Brand Name

Norbactin

Manufacturer

Ranbaxy Laboratories, Dewas, India.

Therapeutic Class

Antibacterial, Quinolones

Dosage Form, Composition & NAFDAC Registration Number (NRN)

Tablet (NRN: 04-2458): Norfloxacin USP 400 mg.

 

Pack: Strip of 10 tablets, box of 5 x 10’s, box of 10 x 10’s.

Norbactin

Pharmacology

Description

Norfloxacin is chemically designated as 1-Ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(piperazin-1-yl) quinoline-3-carboxylic acid.

Mode of Action:

Fluoro-quinolones bring about their bactericidal action by inhibiting the bacterial topoisomerase II (DNA gyrase) enzyme. Topoisomerases are responsible for continuous introduction of negative supercoils into DNA. This is an ATP dependent reaction that requires both strands of the DNA to be cut to permit passage of a segment of DNA through the break; the break is then resealed. Fluoroquinolones decrease the introduction of negative supercoils into DNA and cause rapid cessation of DNA synthesis by interfering with the propagation of DNA replication.

Antibacterial Spectrum:

Norfloxacin is active in vitro against most gram-negative organisms viz, Enterobacteriaceae including Citrobacter species, Enterobacter species, Escherichia coli, Klebsiella species, Proteus species, Salmonella, Shigella and Vibrio species, Pseudomonas aeruginosa including gentamicin resistant strains, and Yersinia enterocolitica. Norfloxacin is active against penicillin resistant strains of Neisseria gonorrhoeae and beta-lactamase producing strains of Haemophilus influenzae and Moraxella catarrhalis. Among gram-positive pathogens streptococci are moderately susceptible in vitro to norfloxacin.

Pharmacokinetics:

Norfloxacin is rapidly absorbed after oral administration. A single oral dose of 400 mg produces a peak plasma concentration of 1.5 mcg/ml achieved 1-2 hours after administration. Absorption of norfloxacin is delayed when given with a meal. Norfloxacin is bound to plasma proteins upto an extent of 14%. It is widely distributed, especially in tissues of the genitourinary tract. High concentrations are achieved in bile. Norfloxacin is partially metabolised in the liver. About 30% is eliminated unchanged in urine. The plasma elimination half-life of norfloxacin is 4 hours.

Indications

Urinary tract infections (complicated and uncomplicated urinary tract infections); Gastroenteritis; Gonorrhoea.

Contra-indications

Hypersensitivity to any quinolone derivative. Potential risks should be carefully considered in patients with cerebral atherosclerosis or epilepsy.

Precautions/Warnings

General:

Photo-toxicity has been observed in some patients receiving fluoroquinolones. Excessive exposure to sunlight should be avoided during norfloxacin therapy. Norfloxacin should be used with caution in patients with epilepsy or a history of CNS disorders. The onset of tendon pain calls for immediate withdrawal of fluoroquinolone antibiotics.

Warnings:

Crystalluria has been reported with norfloxacin at high doses (1200-1600 mg) and in alkaline urine (pH 7 or above). Although crystalluria has not been reported with usual adult doses, fluid intake should be sufficient to maintain urine output of at least 1200-1500 mL/day in adults . It is recommended that doses of norfloxacin should be reduced in patients with impaired renal or hepatic function.

Cross-sensitivity:

Patients hypersensitive to one fluoroquinolone or other chemically related quinolone derivatives may be hypersensitive to norfloxacin as well.

Pregnancy:

Adequate and well controlled studies have not been carried out in humans. Studies in monkeys at doses equivalent to 10 times the maximum human dose have shown that norfloxacin causes embryonic loss and slight maternal toxicity (vomiting and anorexia) as well. Studies in rats, rabbits and monkeys at doses equivalent to 6 to 50 times the human dose have not shown any evidence of teratogenicity.

Lactation:

Norfloxacin has not been detected in breast milk when given to nursing mothers at low doses (200 mg). However, the dose studied was low and other drugs in this class are secreted in human milk. In view of the potential risk of arthropathy in nursing infants, a decision should be made to discontinue either lactation or administration of norfloxacin.

Paediatrics:

Fluoroquinolones are not recommended for use in infants and children as they have been shown to produce permanent lesions of the cartilage in weight bearing joints of immature dogs.

Geriatics:

Studies performed to date have not demonstrated geriatrics specific problems that would limit the usefulness of norfloxacin. However, elderly patients are more likely to have an age related decrease in renal function, which may require an adjustment of dosage.

Interactions

Carbonic anhydrase inhibitors, Citrates, Sodium bicarbonate, Aluminium, calcium or magnesium containing antacids, ferrous sulphate, sucralfate or zinc:

These agents alkalinize urine and reduce the solubility of norfloxacin leading to crystalluria and nephrotoxicity. These agents may reduce absorption of fluoroquinolones, resulting in lower serum and urine concentrations. Therefore, norfloxacin should be taken at least 2 hours before or after any of these medications.

Caffeine:

Norfloxacin reduces the hepatic metabolism and clearance of caffeine, increasing its half-life and the risk of caffeine related CNS stimulation.

Cyclosporine:

Concurrent use with norfloxacin has been reported to elevate serum creatinine and serum cyclosporine concentrations.

Didanosine:

should not be administered concurrently with any fluoroquinolone as concurrent use of didanosine may reduce the absorption of fluoroquinolones.

Probenecid:

Concurrent use of probenecid decreases the renal tubular secretion of fluoroquinolones, resulting in decreased urinary excretion of the fluoroquinolone, prolonged elimination half life and increased risk of toxicity.

Warfarin:

Concurrent use of warfarin with norfloxacin has been reported to increase the anticoagulant effect of warfarin, increasing the chance of bleeding.

Laboratory value alterations:

Serum alkaline phosphatase, SGOT, SGPT and LDH levels may increase.

Adverse Effects

CNS: Agitation, confusion, hallucinations, tremors, headache, insomnia, drowsiness;

Hypersensitivity: Rash, itching, Stevens Johnson syndrome, shortness of breath;

Renal: Interstitial nephritis, crystalluria (when urinary pH exceeds 7.0).

Dosage & Administration

 Urinary tract infections (uncomplicated):   400 mg twice a day for 3 days.
 Urinary tract infections (complicated):   400 mg twice a day for 10 - 21 days.
 Gastroenteritis:   400 mg every twice or thrice a day for 5 days.
 Gonorrhoea   800 mg as a single dose.

Adults with impaired renal function may require a dose reduction as follows:                          

Creatinine clearance  Dose 
 >30 mL/min  Usual adult dose
 <30 mL/min  400 mg once a day

Overdosage

In the event of acute overdosage, the stomach should be emptied by inducing emesis or by gastric lavage and the patient carefully observed and given symptomatic and supportive treatment. Adequate hydration must be maintained.

Storage/Handling Recommendations

Store below 25oC, protected from moisture

Review Date

2016-07-01 08:12:16