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Ofloxacin
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Quinolones
* Non-fluorinated
nalidixic acid
*
Fluorinated (fluoroquinolones)
norfloxacin, ciprofloxacin, ofloxacin, sparfloxacin
- Broader spectrum of activity
- Relatively infrequent development
of resistance
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Ofloxacin
* Synthetic
broad spectrum antimicrobial agent for oral administration
* Orally effective agent for Ps. aeruginosa
* Effective in LRTI, skin and skin structures, STDs and UTI
* Well tolerated
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Mechanism
of Action
* Bactericidal
* Inhibits DNA gyrase, an enzyme essential for supercoiling, duplication,
transcription, and repair of bacterial DNA
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Antibacterial
Spectrum
Aerobes,
Gram-Positive: Staph.
aureus, Staph. epidermidis, Strep. pneumoniae, Strep. pyogenes
Aerobes, Gram-Negative: E. coli, Klebsiella
pneomoniae, Enterobacter aerogenes, E. cloacae, H. influenzae, H.
ducreyi, P. mirabilis, P. vulgaris, Ps. aeruginosa, N. gonnorhoeae,
Serratia marcescens, M. catarrhalis
Other microorganisms : Chlamydia, Mycoplasma, U. urealyticum,
M. tuberculosis
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Resistance
Resistance
is rare
- due to spontaneous mutation
(10-9 to 10-12 ) approx.
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Pharmacokinetics
- Oral bioavailability
- 98% approx.
- Cmax 2.2 mcg/ml in 1- 2 hours with
200 mg orally
- Widely distributed in body tissues and fluids including blister
fluid, cervix, lung tissue, ovary, prostatic fluid & tissue, skin,
and sputum
- Mainly renal excretion, average urine conc. with a single 200 mg
dose is 220 mcg/ml. approx. Clearance reduced in patients with impaired
renal function
- 4-8% excreted in the feces
- Half-life 5-6 hours in young adults; 7-8 hours in elderly
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Indications
Lower
Respiratory Tract Infections
- Acute bacterial exacerbations of chronic bronchitis
- Community-acquired pneumonia
Skin and Skin Structure infections
Sexually Transmitted Diseases
- Gonorrhea
- Nongonococcal urethritis and cervicitis due to Chlamydia trachomatis
- Mixed infections
Urinary
Tract Infections
- Uncomplicated & complicated urinary tract infections
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Adverse
Reactions
- Generally
well tolerated
- Nausea, insomnia, headache, dizziness, diarrhoea, vomiting, rash,
pruritus, external genital pruritus in women, vaginitis, dysgeusia.
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Precautions
& Contraindications
- Caution
in patients with renal and hepatic impairment and a known or suspected
CNS disorder
- Use in pregnancy only if potential benefit justifies potential risk
to the fetus. Produces concentrations in milk , hence caution in lactating
women
- Contraindicated in persons with a history of hypersensitivity to
ofloxacin or other quinolones
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Drug
Interactions
- Antacids,
sucralfate, iron and zinc interfere with absorption
- Inhibits cytochrome P450 enzyme activity; may result in prolonged
half-life for drugs metabolized by this system (e.g., cyclosporine,
theophylline / methylxanthines, warfarin, etc.)
- Monitor blood glucose levels in diabetics as disturbances of blood
glucose may occur in patients treated with quinolones & antidiabetics
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Dosage
Adults :
200-400 mg daily usually for 5-7 days . Dose greater than 400
mg should be given in 2 divided doses
Urinary Tract Infections : 200-800 mg daily ,
Lower respiratory tract infection : 400-800 mg daily,
Gonorrhoea : 400 mg as single dose
Not recommended for children
Renal disease : I n patients with creatinine clearance < 50
ml/min give a normal initial dose, followed by the usual recommended
unit dose q24h
Patients with Cirrhosis: A maximum dose of 400 mg should not be exceeded.
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Salient
Features
- Broad spectrum
coverage especially gm -ve bacteria
- Oral therapy for Pseudomonas aeruginosa infection
- Effective against bacteria resistant to other important agents e.g.,
penicillins and cephalosporins
- Resistance is rare
- Wide distribution in the body
- Convenient dosing
- Effective in LRTI, skin and skin structures, STDs and UTI
- Well tolerated
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