The document summarizes quinolones and fluoroquinolones, a family of broad-spectrum antibacterial agents. It discusses their mechanism of action, which involves inhibiting bacterial DNA gyrase and topoisomerase IV, blocking DNA synthesis. Common examples like ciprofloxacin, norfloxacin, ofloxacin, pefloxacin and levofloxacin are described in terms of their pharmacokinetics, therapeutic uses, doses, and adverse effects which include gastrointestinal issues and central nervous system effects. Mechanisms of resistance and drug interactions are also covered at a high level.

1. Quinolone & Fluoroquinolones
Presented By
Dr. Manoj Kumar
Assistant Professor
Department of Pharmacology
Adesh Medical College & Hospital Ambala Can’t

2.  The fluoroquinolones are a family of broad spectrum,
systemic antibacterial agents that have been used
widely as therapy of respiratory and urinary tract
infections.
Defination

3. Quinolone
NALIDIXICACID
• Available for the managementofUTI.
• Limited therapeutic ability.
•A/E–GI upset, rashes,neurological toxicity, hemolysis.
• Bacterialresistance.

4. 4

5.  Fluroquinolones are bactericidal agents.
 They block bacterial DNA synthesis by
inhibiting bacterial DNA gyrase and
topoisomerase IV.
 Inhibition of DNA gyrase prevents the
relaxation of positively supercoiled
 DNA is required for normal transcription and
replication
 Inhibition of topoisomerase IV interferes
with separation of replicated chromosomal
DNA into the respective daughter cells
during cell division.
Mechanism of Action

6. Mechanism of Resistance

7.  Well absorbed orally, except norfloxacin.
 Bioavailability highest in gatifloxacin (>98%).
 Attend higher concentrations in urine, kidney, bone, genital tract,
prostate, lung & bronchial mucosa.
 CSF penetration low except in pefloxacin.
 Elimination renal.
 Food delays absorption of ciprofloxacin, norfloxacin, pefloxacin &
lomefloxacin.
 Have prolonged post antibiotic effect (6 hours).
Pharmacokinetics

8.  GIT :Nausea, abdominal discomfort, vomiting, diarrhoea.
 CNS :Headache, dizziness, agitation, alteration of mood, sleep
disturbances, seizures, hallucinations, delirium.
 Hypersensitivity : Allergic reactions, rash, purities, rarely fever,
urticaria, angioedema.
 Lomefloxacin, sparfloxacin and moxifloxacin cause phototoxicity.
 Sparfloxacin, moxifloxacin and gatifloxacin prolong QT interval on
ECG.
 Crystalluria, Arthralgias and cartilage erosions with joint swellings.
Adverse effects

9.  Food,Antacids & Iron: Decreaseabsorption
 Theophylline, caffeine, warfarin: increased serum
concentration.
 EnzymeInhibition.
 NSAIDsmayincreaseCNStoxicity. (Seizures)
Drug interactions

10.  UTI
 TB
 Typhoid
 Diarrhoea
 Gonorrhoea
 Chancroid
 Respiratory tract infections.
 Eye infection.
 Anthrax.
 Neutropenic patients.
 Gram-negative septicaemias
 Bone, Joint, Soft tissue and
intra-abdominal infections.
Therapeutic Uses

12.  Most commonly used (FQ).
 Very active against gram negative aerobes and Staphylococci.
 Food delays absorption.
 Bioavailability 60-70 % & t1/2 3-5 hours.
 Excretion in urine and faces.
 Dose: 250 -750 mg 12hourly.
 Gonorrhoea: 500 mg BD.
 Chancroid: 500 mg BD for 3 days.
Ciprofloxacin

13.  Serum concentrations low outside genitourinary and intestinal tract.
 Food decreases absorption.
 Bioavailability 35-40 % & t1/2 4.5 hours.
 No interaction with theophylline and caffeine.
 Useful in long term prophylaxis in recurrent UTI & travelling
diarrhoea.
 Dose: 400 mg 12 hourly.
 Gonorrhoea: 800 mg OD.
 UTI prophylaxis: 200 mg OD.
Norfloxacin

14.  More active against some anaerobes, M. tuberculosis, M.
leprae.
 Use in multidrug regimens in leprosy & TB (300-800
mg/day.)
 Food does not interfere with absorption.
 Penetrates CSF & t1/2 5-7.5 hours.
 Bioavailability 95%
 Crosses BBB & excreted unchanged by the kidneys.
 No interaction with theophylline and caffeine.
Ofloxacin

15.  Highly lipid soluble derivative of norfloxacin.
 Food delays absorption.
 Bioavailability 90% & t1/2 8-13 hours.
 Better tissue penetration
 Higher concentration in CSF.
 Dose to be reduced in hepatic insufficiency.
 Increases levels of theophylline and caffeine.
Pefloxacin

16.  Oral bioavailability >95% & Food delays absorption.
 Widely distributed & t1/2 6-7.5 hours.
 Excreted unchanged over 24 hours.
 Incidence of phototoxicity highest.
 No interaction with theophylline and caffeine.
 Used in respiratory infection, urinary, skin and soft tissue infection.
 Dose: 400 mg OD.
Levofloxacin

17.  More active than ciprofloxacin against Staphylococci, Streptococci,
Mycobacteria, Mycoplasma.
 Food does not interfere with absorption.
 Longest t1/2 16-3O hours & Bioavailability 90%
 Phototoxicity seen in 8% patients,
 Increases QT interval on ECG.
 No interaction with theophylline, caffeine and warfarin.
 Banned in many countries including India.
 Dose: 200 mg OD.
Sparfloxacin

18.  Oral bioavailability >90% & t1/2 6-8 hours.
 Active as ofloxacin.
 CSF penetration good remains in the tissues for a longer
period.
 Used in the treatment of urinary and respiratory tract
infection.
 Dose: 500 mg OD.
Lomefloxacin

19.  Second generation FQ & Oral bioavailability >85%.
 t1/2 12hours & excretion in urine.
 Improved gram positive activity including penicillin-resistant S.
pneumoniae and anaerobes.
 Less active against enterobacteriacea, Pseudomonas.
 Phototoxicity, CNS adverse effects common & prolongs QT interval on
ECG.
 Not interfere with theophyllin or warfarin.
 Dose: 400 mg OD
Moifloxcin

20.  Second generation FQ
 Oral bioavailability 95% & t1/2 7-10 hours.
 Increased activity against penicillin resistant S. pneumonia.
 Excreted unchanged by the kidneys
 Can prolong QT interval on ECG.
 Used in respiratory and genitourinary infection.
 Banned in many countries, available in India.
 Dose: 400 mg OD.
Gatifloxacin

21.  Potent broad spectrum quinolone used topically.
 Good activity against gram positive bacteria and
anaerobes.
 Can be absorbed systemically on topical application.
 Not recommended for simple infections like acne.
 Indicated for bacterial skin infections.
Nadifloxacin

22.  Children (not absolute)
 Pregnancy
 Lactation
 Epilepsy
 QTc prolongation
Contraindication

23. THANK YOU
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