Pefloxacin

Pefloxacin is an antimicrobial agent. It is a synthetic fluoroquinolone, belonging to the 3rd generation of quinolones.

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Mode of Action

• Chromosomal DNA in bacterial cells occurs mainly in the form of a double stand ring.
• One of a group of bacterial enzymes- DNA gyrase is responsible for the supercoiling process.
• Pefloxacin bactericidal affect is due to its ability to inhibit the activity of this vital enzyme.
• The result of this inhibitions is the prevention of bacterial DNA replication.
• Although inhibition of DNA replication is undoubtedly the chief means by which Abaktal exerts its antibacterial effect, two other actions are also observed:
  • Pefloxacin reduces the ability of E-coli and staphylococcus to adhere to the walls of uroephithelial cells.
  • Pefloxacin has effects on the immune system, stimulating the phagocytic activity of white blood.

Spectrum of antibacterial activity

• Extensive in vitro & in vivo testing has established that Abaktal has a broad antibacterial spectrum.
• The MICs of Pefloxacin even against bacteria resistant to beta-lactams and aminoglycosides are very low
• Initial plasma level of 4.0 mcg/ml, well above M.I.C. for sensitive pathogens, are ready and rapidly attained after a single 400mg dose (oral or i.v.)
• Excellent tissue penetration level is achieved with Pefloxacin in human and animals studies
• Species usually sensitive (MIC < 1pg/ml)are Escherichia coli, Klebsiella, Enterobacter, Serratia, Proteus mirabilis, Proteus vulgaris, Citrobacter, Salmonella, Shigella, Haemophilus influenzae, Staphylococcus aureus, and Neisseria gonorrhoeae.
• Species variably sensitive include Streptococcus and Pneumococcus, Pseudomonas aeruginosa, Acinetobacter, Clostridium perfringens, Mycoplasma, and Chlamydia.

Pharmacokinetics

• After oral administration, Abaktal is well absorbed; the bio availability is 100%.
• Peak plasma levels is reached in 1-1.5 hours
• Peak serum levels of 3.8-6.6mcg/ml is attained after single dose of 400mg
• Peak serum levels after multiple dose of 400mg, 12 hourly is 8-10 mcg/ml
• Steady state concentration is achieved
• Dose depended increase in plasma level over the dose of 200- 800mg
• Food slows the absorption but does not effects bio availability
• Oral & injectable forms are bio-equivalent
• Elimination half life is 11-12 hours mainly through metabolites
• Pefloxacin is metabolized in liver (85%-90%)
• Plasma protein binding is 20-30%
• Major route of elimination is renal – 9-16% of the drugs is eliminated unchanged
• Major metabolites constitute up to 84% of drugs recovered in urine
• Limited excretion via bile
• N-dismethyl pefloxacin (norfloxacin) activity unknown
• Pefloxacin N-oxide active
• Oxodimethyl activity unknown
• Oxo pefloxacin activity unknown
• Pefloxacin achieves high tissue concentration

Tissue Concentration Bronchial tissues 5 mcg/ml Oropharyngeal concentration 6 mcg/ml Tonsils 9 mcg/ml Maxillary sinus cavity sinus 2.82 mcg/ml, 4.1 mcg/ml, 2-8mcg/ml aspirate sinus cystic fluid nasal secretions Muscles 5.6 mcg /ml Gall bladder 80 mcg /ml Bile 78 mcg /ml Kidney 90 mcg /ml Prostate 10 mcg /ml Gynecological tissue 38 mcg/ml 4-6 higher than serum conc., Myometrium- 38.6 mcg /ml, Fallopian tube 31.9 mcg /ml, Ovaries 44.8mcg/ml Pancreatic tissue 4.6mcg/ml Peritonium 3.5mcg/ml

• There are no major change in plasma pharmacokinetics as a function of renal impairment
• Elimination half life increase slightly to approx.15 hours
• There is a fall in urinary excretion of Abaktal & its metabolites
• There is no major change in Abaktal plasma levels whatever the degrees of renal impairment
• Pefloxacin is not readily dialyzed
• There are marked changes in pharmacokinetics in patients with hepatic impairment
• Marked increase in :
  • Elimination half life 3-5 times
  • Area under curve 3-6 times
  • Urinary excretion of unchanged Abaktal 3-4 times
• Careful monitoring of plasma levels together with appropriate dosage adjustment will be necessary

Indications

Indicated for the following conditions:

• Respiratory infections
• Ear, nose and throat infections
• Renal and urinary infections
• Gynaecological infection
• Abdominal and hepato-biliary infections
• Bone and joint infections
• Skin and soft tissue infection
• Septicaemia and endocarditis

Contraindications

• Children or adolescents
• Pregnant women
• Nursing mothers
• History of hypersensitivity to quinolones
• Patients with a history of tendon lesion tendinitis or tendon rupture

Precaution & side effects

Precautions

• Hepatic dysfunction
• Avoid exposure to sunlight during treatment

Side effects

• Nausea
• Skin rash
• Photo sensitivity reaction
• Insomnia
• Headache
• Myalgia
• Thrombo-cytopenia

Drug comparisons

Pefloxacin vs. Ciprofloxacin

Pefloxacin vs. Norfloxacin

Dosage & Presentation

Oral Tablets: 400mg Twice daily

Injection: Administer by slow I.V. at a dosage of 400mg diluted in 100 or 250 ml of 5% isotonic solution (Over a period of 1 hr) Twice daily