Antibiotics MOA Flashcards
Penicilins
Bind PBP (transpeptidases) to block transpeptidation/ cross linking of peptidoglycans. activates autolytic enzymes
Penicillinase resistant penicillins
Bind PBP (transpeptidases) to block transpeptidation/ cross linking of peptidoglycans. activates autolytic enzymes Penicillinase resistant bc the bulky R group blocks access of beta lactamase to the beta lactam ring
Ampicillin, Amoxicillin
Bind PBP (transpeptidases) to block transpeptidation/ cross linking of peptidogycans. Activates autolytic enzymes
Ticarcillin, Pipercillin (antipseduomonal penicillins)
Bind PBP (transpeptidases) to block transpeptidation/ cross liking of peptidoglycans. Activates autolytic enzymes
Cephalosporins
Beta-lactam drugs that inhibit cell wall synthesis
Aztreonam
Binds to PBP3 to prevent peptidoglycan cross linking
Imipenem/ Cislastin
Cislastatin keeps Imipenem in the system as a broad spectrum beta-lactamase- resistant carbapenem
Vancomycin
Binding D-ala-D-ala inhibits cell wall peptidoglycan formation
Aminoglycosides
Inhibit formation of initiation complex and cause misreading of mRNA. block translocation.
require O2 for uptake
Tetracyclines
Bind 30s and prevent attachment of aminoacyl tRNA
Macrolides
binds to 23s rRNA of 50S ribosomal subunit
Chloramphenicol
Blocks peptidyltransferase 50s ribosomal subunit
Clindamycin
Blocks peptide transfer transpeptidation at 50s ribosomal subunit
Sulfonamides
PABA antimetabolites inhibit dihydropterate synthase
TMP
inhibts bacterial dihydrofolate reductase
Fluoroquinolones
Inhibit DNA gyrase topoisomerase II and topoisomerase IV
Metronidazole
Forms free radical toxic metabolites that damage DNA
Isoniazid
decreases synthesis of mycolic acid in KatG (peroxidase) positive bacteria
Rifampin
Inhibits DNA dependent RNA polymerase
Pyrazinamide
Unknown
Ethambutol
Blocks arabinosyltransferase- decreases carbohydrate polymerization of mycobacterium cell wall.
Amphotericin B
Binds ergosterol –> formation of membrane pores that allow electrolyte leakage
Nystatin
Binds ergosterol –> formation of membrane pores that allow electrolyte leakage
Azoles
Inhibits the P-450 enzyme that converts lanosterol to ergosterol (fungal sterol)
Flucytosine
Inhibits DNA and RNA biosynthesis by conversion of 5-FU by cytosine daminase
Caspofugin, micafugin
inhibits beta glucan synthesis which leads to inhibition of cell wall synthesis
terbinafine
Inhibits squalene expoxidase- a fungal enzyme
Griseofluvin
Interferes with microtubule function- disrupts mitosis.
Deposits in keratin containing tissues
Chloroquine
Blocks detoxification of heme into hemozoin. heme accumulates and is toxic to plasmodia
Zanamivir, Oseltamivir
Inhibits Influenza Neurominidase decreasing the release of pyrogeny virus
Ribavirin
Competitive inhibition of IMP dehydrogenase inhibiting the synthesis of guanine nucleotides
Acyclovir, Fanaciclovir
Guanosine analog monophosphorylated by HSV/HZV thymidine kinase. cellular enzymes form the triphosphate.
Preferentially inhibits viral DNA polymerase by chain termination
Ganciclovir
Guanosine analog- CMV viral kinase forms a 5’-monophosphate. Triphosphate is formed by cellular kinases.
Preferentially inhibits viral DNA polymerase
Foscarnet
Binds to the phosphate binding site of viral DNA polymerase.
Does not require activation by a viral kinase
Cidofovir
Preferentially inhibits viral DNA polymerase. Does not require phosphorylation or viral kinase
"-navir" Lopinavir Atazanavir Darunavir Fosamprenavir Saquinavir Ritonavir Indinavir
Protease inhibitors- blocks cleavage of HIV mRNA into functional parts preventing maturation of new viruses
Abacavir Lamivudine Zidovudine (AZT) Didanosine Stavudine Emtricitabine
NRTI’s- Lack 3’OH group –> inhibit nucleotide binding to reverse transcriptase and terminate DNA chain. Nucleoside analog –> require activation
Tenofovir
NRTI- nucleotide analog thus does not require activation.
Nevirapine
Efavirenz
Deliviridine
non competitive inhibitor of reverse transctiptase. Do not require phosphorylation
Raltegavir
Integrase Inhibitor- inhibits HIV genome integration into host cell chromosome by reversibly inhibiting HIV integrase.