Antibacterials 5 Flashcards
Sulfonamides structurally similar to
PABA
Sulfonamides moa
Inhibitors of folate metabolism
Sulfonamides are more soluble in alkaline pH?
Yes
Prevents conversion of PABA and pteridine to dihydropteroic acid
Sulfonamides
Prevents conversion of dihydrofolic acid to tetrahydrofolic acid
Trimethoprim
Drug of choice for
Pneumocystis jiroveci pneumonia
Toxoplasmosis
Nocardosis
Cotrimoxazole
Cotrimoxazole components
Trimethoprim
Sulfamethoxazole
Bacteriostatic whentaken ind but bactericidal when taken together
Trimethoprim and sulfamethoxazole
First line drug for typhoid fever
Cotrimoxazole
Gram pos S aureus inc MRSA, S pyogenes, S pneumonia
Gram neg Haemophilus spp, E coli, Proteus mirabilis, Salmonella spp
Cotrimoxazole
30S inhibitors
Aminoglycosides
Tetracyclines
Reversible 30 S inhibitor
Tetracycline
Irreversible 30S inhibitor
Aminoglycosides
Aminoglycosides more active in what pH?
Alkaline
Mycins?
Aminoglycosides
Aminoglycosides synergistic with
Beta lactams
Moa of Aminoglycosides
Interference with initiation complex
Breakup of polysome
Misreading mrna
Ototoxic and nephrotoxic when continued at high doses for long periods
Aminoglycosides
Most ototoxic agents, Aminoglycosides
Neomycin
Kanamycin
Amikacin
Most nephrotoxic aminoglycosides
Neomycin
Tobramycin
Gentamicin
Aminoglycoside, no activity for anaerobes
Gentamicin
Can be administered intrathecally, aminogly
Gentamicin
Acid stable 30s inhibitor
Tetracyclines
Moa of tetracyclines
Blocks binding of aminoacyl-tRNA to acceptor site
30S inhibitor with anaerobe activity
Tetracyclines
Tetracycline resistance moa
Impaired influx, increased efflux Tet-AE
Ribosome protection, interfere binding Tet-M
Inactivation
Absorption of tetracycline impaired by
Food
Divalent cations
Dairy products and antacids
Alkaline pH
Chelate with metals, dont administer with milk, antacids, ferrous sulfate
Tetracyclines
Who should avoid tetracyclines?
Pregnant women
Children less than 8
Drug of choice against rickettsiae
Tetracyclines
Used in combination regimens to treat ulcers caused by H pylori
Tetracyclines
IV injection can cause venous thrombosis
Tetracyclines
Preferred for atypical microbes, Chlamydia, Mycoplasma
Doxycycline
Elimination of doxy
Non renal
Doxycycline admin
iV
Oral
Chlamydia, mycoplasma pneumoniae, cholera, leptospirosis, malaria
Doxycycline
50S inhibitors
Chloramphenicol
Macrolides
Clindamycin