One bacterium can reproduce into over 2 million in 7 hours. Quinolones are synthetic antimicrobials active against gram-negative bacteria. Nalidixic acid was the first quinolone developed in the 1960s, while later fluoroquinolones in the 1980s were more potent and had broader spectra. Fluoroquinolones work by inhibiting bacterial DNA gyrase and topoisomerase IV, and are generally well-absorbed with few resistance issues. Common uses include urinary tract infections and respiratory, gastrointestinal, and skin infections. Adverse effects can include nausea, tendon damage, and interactions with other drugs.
26. NALIDIXIC ACID
USES
as urinary antiseptic - second line drug for recurrent
UTI
G –ve diarrhoeas (E.coli, shigella, salmonella,
proteus )
Ampicillin resistant shigella entertis.
33. MECHANISM OF ACTION
Inhibit bacterial DNA GYRASE( in GRAM --VE)
interfere with strand cutting ,resealing function
Damage DNA digestion of DNA
Inhibit topoisomerase IV ( in GRAM +VE)
Bactericidal
42. FEATURES OF FQs
Rapidly bactericidal
Concentration dependent bacterial killing
Long postantibiotic effect
Low frequency of mutational resistance
Sparing of protective intestinal bacteria
Active against many β-lactam, aminoglycoside
resistant bacteria
72. INTERACTIONS
Inhibit cyp450 microsomal enzymes → ↓metabolism
↓
↑Toxicity of sulfonylureas ,
theophylline ,
warfarin
NSAIDs →↑ CNS toxicity of FQs
Antacids , iron →↓ Absorption of FQs
73.
74. THERAPEUTIC USES
Typhoid fever
UTI
Bacterial gastroenteritis
Chancroid
Gonorrhoea
Anthrax
Bone ,soft tissue infection due to to susceptible
organism
Gynecological infection , wound infections
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85. THERAPEUTIC USES
Diabetic foot
MDR tuberculosis
G-ve septicaemias , meningitis
Conjunctivitis by g-ve bacteria(topical )
Respiratory Infections due to susceptible organisms
Prophylaxis of infections in neutropenics/ cancer
patients
86.
87.
88.
89.
90.
91.
92. IN DENTISTRY
Not indicated for any acute orofacial infections unless
culture & sensitivity reports
Not synergistic with β lactam , aminoglycosides.
Rapidly progressive or
refractory periodontitis associated with
Enterobacteriaecae - culture & sensitivity test
100. PEFLOXACIN
Methyl derivative of norfloxacin
More lipid soluble
Better tissue penetration
Passage into CSF higher than other FQs→ →
preferred for meningitis
Longer t ½
Cumulation useful in many systemic INF→
Doses reduced in hepatic disease
Alternative to cipro in typhoid
101.
102.
103.
104.
105.
106. OFLOXACIN
More potent for G+ve infections
Also effective against Chlamydia , Mycoplasma ,
M.leprae , M.tuberculosis
Lipid soluble
High oral BA
cyp450 inhibition less
↓dose in renal failure
Indications RI ,ENT infection , NGU, gonorrhoea ,→
tuberculosis , leprosy , atypical pneumonia
120. LOMEFLOXACIN
II nd generation FQ
More active on some G-ve bacteria , Chlamydia
Single daily dose
↓dose in renal failure
↑ warfarin levels
121.
122.
123. SPARFLOXACIN
Enhanced action on G +ve bacteria
Strep. Pneumoniae,
staphylococci,
enterococci ,
bacteroides and other anaerobes,
mycobacteriae
Single daily dose
124.
125. SPARFLOXACIN – ADR & DRUG
INTERACTIONS
No CYP 450 interaction
Phototoxicity +( patients advised not to go in sun)
Slight prolongation of Qtc interval
141. MOXIFLOACIN
Spectrum -G+ve
β lactam /macrolide resistant bacteria
Atypical respiratory pathogens
Most potent FQ in tuberculosis
URI /LRI, not good for UTI
ADR similar ,predispose to seizures , arrhythmias→
Long acting