Pharma LRTI Flashcards
Bronchitis treatment
Amoxicillin, Clavulanic Acid,
Bronchiolitis treatment
supportive:
oxygen inhalation, bronchodilators, mechanical
o
ventilation, parenteral fluids to limit dehydration, correct respiratory acidosis and
electrolyte imbalance, etc.
children under the age of 8 with bronchitis are usually given
amoxicillin
Broad spectrum
Tetracyclines
Bacteriostatic drug
Tetracyclines
Co-trimoxazole (sulfamethoxazole & trimethoprim)(antifolate)
used to treat Pneumocystis
corinii infection in patients with AIDS.
Co-trimoxazole (sulfamethoxazole & trimethoprim)
Folic Acid Antagonists or Anti-folates:
Co-trimoxazole (sulfamethoxazole & trimethoprim)
Sulofonamides are structural analogues for
PABA
Sulofonamides inhibit enzyme
dihydropteroate
synthetase
Trimethoprime inhibits the enzyme
dihydrofolate reductase
Sulofonamides inhibit synthesis of
Folate
Trimethoprime inhibit synthesis
tetrahydrofolic acid
tetrahydrofolic acid synthesis an important cofactor in
thymidylate (and hence DNA) synthesis.
Unwanted effects of sulfonamides include
hepatitis, hypersensitivity reactions, bone marrow depression and crystalluria.
Unwanted effects of trimethoprim include
blood disorders and skin rashes.
Folate deficiency can be prevented by giving
folinic acid.
The cell wall of bacteria contains———-, which is not found in eukaryotic cells.
peptidoglycan
Inhibit cell wall synthesis
β-Lactams (amoxicillin, cefotaxime, penicillin)
Bactericidal drugs
β-Lactams (amoxicillin, cefotaxime, penicillin)
-Glycopeptide Antibiotics: Vancomycin
β-Lactams (amoxicillin, cefotaxime, penicillin) inhibit the enzyme
bacterial transpeptidase enzymes
bacterial transpeptidase enzymes responsible for
cross-linking peptide chains of peptidoglycan and hence cell wall synthesis.
The intrinsic activity of β-lactam antibiotics against a particular organism depends on its ability to gain access to and bind with the necessary.
PBP.
penicillin-binding-proteins
broad spectrum
β-Lactams (amoxicillin, cefotaxime, penicillin)
β-Lactams (amoxicillin, cefotaxime, penicillin)
Adverse reactions:
Hypersensitivity
Cross-sensitivity or cross-alergenicity.
Nausea, vomiting, diarrhea.
Mechanisms of bacterial resistance to penicillins & cephalosporins (β- Lactams)
Most common.
Inactivation of the drug by β-Lactamases
Beta lactamase inhibitors:
Clavulanic acid
Monobactams
Carbapenems
Clavulanic acid Given in combination with
hydrolyzable β-lactamases e.g., amoxycillin (co-amoxiclav).
Glycopeptide Antibiotics ex
Vancomycin
Glycopeptide Antibiotics: Vancomycin
inhibits bacterial cell wall synthesis by binding to
D-Ala-D-Ala region of the peptidoglycan
Glycopeptides bind to precursors of cell wall
synthesis and inhibit
peptidoglycan elongation
Glycopeptides Binding of penicillin (D-Ala-D-Ala residue)
and results in
alteration of bacterial cell wall permeability.
Glycopeptide Antibiotics Inhibit- synthesis
RNA
Glycopeptide Antibiotics: Vancomycin
Ototoxicity and nephrotoxicity.
Useful against MRSA, S. epidermidis infections, and gram +ve infections in penicillin allergic patients.
Glycopeptide Antibiotics: Vancomycin
Vancomycin Not absorbed orally, given i.v. except in case of
Clostridium difficile colitis (GIT infection
Tetracyclines bind to — bind to
30S
inhibit protein synthesis (inhibit tRNA binding to mRNA)
Tetracyclines
It’s Adverse effects:
Hepatotoxicity, phototoxicity
Teratogenic effects
and serious effect on developing teeth (permanent yellow/brown).
Tetracyclines
bind irreversibly to 30S > misreading of the message
Aminoglycosides: streptomycin
Aminoglycosides: streptomycin
Characteristics
Killing is concentration dependent
Exhibit Post Antibiotic Effect (PAE)
not susceptible to aminoglycosides
Anaerobic bacteria
Adverse effects:
Aminoglycosides: streptomycin
Nephrotoxicity, ototoxicity, neuromuscular blockade.
Low therapeutic index
Macrolides: erythromycin bind to
50S
Macrolides: erythromycin inhibit
translocation. (Movement to E, exit site)
Macrolides: erythromycin inhibit or inactivate which drug
1) digoxin
2) Cyt-P450 &
3) metabolism of other drugs (e.g. warfarin).
Macrolides interact/inactivate digoxin,causes
destroy gut flora, leading to its greater
reabsorption from enterohepatic circulation and higher levels in plasma.
reversible ototoxicity.
Hypersensitivity GI disturbances Cholestatic Jaundice
Macrolides
Lincosamides: Clindamycin binds to— > inhibit protein synthesis
50S
binds to 50S at the same sites of erythromycin & clindamyci
Chloramphenicol
Chloramphenicol inhibition of
mitochondrial protein synthesis in bacterial cells (inhibit transpeptidation, movement from P to A)
Adverse effects:
Limited use due to serious side effects of antibiotic-associated colitis.
Lincosamides: Clindamycin
Gray baby syndrome
Chloramphenicol
interfere with 50S & 30S ribosomal subunit assembly
Oxazolidinones: Linezolid
Oxazolidinones: Linezolid
Treats
skin and skin structure infections, nosocomial pneumonia (MRSA and non MRSA caused)
In hibitors of DNA synthesis:
2
1) Fluoroquinolones: Ciprofloxacin
2) Nitroimidazoles: Metronidazole
Nitroimidazoles: Metronidazole
Most effective against—— bacteria
anaerobic
like Aminoglycosides. exhibit concentration- dependent bacterial killing and a prolonged post-antibiotic effect (PAE)
Fluoroquinolones
