Flashcards in Antimicrobials Deck (111):
What is the MOA of PCNs?
binds PBPs and block the transpeptidase cross-linking of peptidoglycan
Activate autolytic enzymes
What, generally, are the bacteria that PCNs are used to treat?
What is the major adverse reaction to PCNs?
How is resistance to PCNs conferred to bacteria?
Penicillinase in bacteria to cleave the beta-lactam ring
What are the three major beta lactamase inhibitors? (CAST)
What are the two major anti-pseudomonal PCNs?
Ticarcillin and piperacillin
What are the three major penicillinase resistant PCNs? What bacteria do these typically treat?
"Naf for staph"
What are the two major penicillinase-sensitive abx?
Which has more oral availability: amoxicillin or ampicillin?
AmOxicillin has more O-ral availability
What are the bacteria that ampicillin/amoxicillin are used to treat? (HELPSS)
What is the general MOA of cephalosporins? Are these bactericidal or bacteriostatic?
Beta-lactam drugs that inhibit the cell wall synthesis, but are less susceptible to Penicillinases
What are the two first gen cephalosporins, and what are the three bacteria that they usually treat? (PEcK)
What are the three major third generation cephalosporins, and what are the 7 bacteria that they are used to treat? (HEN PEcKS)
What is the general side effect of most cephalosporins?
Hypersensitivity rxn and it K deficiency
What other abx should never be combined with cephalosporins? Why?
What is the only monobactam abx? MOA? Is this beta-lactam resistant?
Resistant to beta lactamases
Prevents peptidoglycan cross-linking by binding to PCN-bind proteins
What is the abx that prevents peptidoglycan cross-linking by binding to PCN-bind proteins?
What is the major side effect of aztreonam?
Occasional GI upset
What is the major bacterial type that aztreonam usually works against?
Gram negative rods ONLY
What two conditions are ceftriaxone used to treat?
What condition is ceftazidime used to treat?
What, generally, happens to the spectrum of activity as you progress in the generations of cephalosporins?
What is the MOA of carbapenems?
PCN-like--binds to PBPs and disrupts cell wall synthesis
Imipenem is always administered with what drug? Why?
Cilastatin to inhibit renal dehydropeptidase I
"The kill is lastin' with cilastatin"
What are the three general categories of bacteria that carbapenems are used against?
Gram positive cocci
Gram negative rods
What are the side effects of carbapenems? (2)
Seizures at high plasma levels
What is the MOA of vancomycin?
Inhibits cell wall peptidoglycan formation by binding D-ala D-ala portion of cell wall precursors
What are the bacteria that vanco are used to treat?
Gram positive only
What are the side effects of vanco? ("NOT trouble free")
Red man syndrome
How can you prevent red man syndrome with Vanco?
Slow administration + antihistamines
What is the Mechanism of resistance against Vanco?
Amino-acid modification of D-ala D-ala
"Pay back 2 D-alas (dollars) for Vandalizing (Vanco)"
What are the two major 30s ribosome inhibitors? Which is bactericidal/bacteriostatic?
What are the three 50s ribosome inhibitors? Which is bactericidal/bacteriostatic?
-Chloramphenicol and clindamycin (bacteriostatic)
-Erythromycin (macrolides) (bacteriostatic)
What is the mnemonic for recalling the30s and 50s ribosome inhibitors?
"Buy AT 30, CCEL at 50"
MOA of aminoglycosides?
30s inhibitors--inhibit formation of initiation complex
MOA of macrolides?
50s inhibitor--inhibits the macro"slide"--blocks translocation
MOA of tetracyclines?
30s inhibitor--prevents attachment of tRNAs
MOA of linezolid?
MOA of chloramphenicol? Toxicity?
50s inhibitor-- blocks peptidyl transferase
Causes anemia and gray baby syndrome
MOA of clindamycin? What infections is this used to treat?
50s inhibitor--Blocks peptide transfer
Treats infections above the waist
What is the 30s subunit responsible for? 50s?
30s is small guy on the bottom that binds mRNA, 50s is the big guy on top that gets all the tRNAs
What is the suffix of aminoglycosides?
-micin or -mycin
What are the major toxicities of aminoglycosides? (NNOT)
What is the MOA of resistance against aminoglycosides?
Bacterial transferase enzymes inactivate the drug by acetylation
What is the suffix for tetracyclines?
What is the MOA of resistance for tetracyclines?
Decreased uptake/increase efflux
What are the major toxicities of tetracyclines?
Discoloration of teeth and inhibition of bone growth in children
What is the MOA of resistance to macrolides?
Methylation of the 23s rRAN binding protein
What antibiotic causes gray baby syndrome, and why?
Chloramphenicol since infants lack UDP-glucuronyl transferase needed to breakdown it
What abx treats infections above the waist? Below?
Above - clindamycin
Below - metronidazole
What is the drug that is highly associated with causing C.diff?
What is the MOA of sulfonamides? Use? Toxicity? MOA of resistance?
Inhibits folate synthesis
Gram positives and negatives
Hemolysis in G6PD, nephrotoxic
Altered bacterial DHP synthase)
What are the three macrolides?
What is the MOA of trimethoprim? Toxicity?
Blocks bacterial dihydrofolate reductase
Megaloblastic anemia and leukopenia
What is the MOA of fluoroquinolones? Suffix? Clinical use? Toxicities (2)? MOA of resistance?
Inhibits DNA gyrase (topoisomerase II)
-Gram negative rods
-Tendonitis + prolonged QT
-Mutation in DNA gyrase
What is the MOA of metronidazole? Toxicity?
Free radical damage to DNA
What are the infections (parasites and bacteria) that metronidazole is used to treat? (GET GAP on the metro)
What are the four components of TB treatment (RIPE)?
What is the drug of choice for prophylaxis against TB? MAC?
TB = isoniazid
MAC = Azithromycin + rifabutin
What is the MOA of isoniazid? Toxicities?
Decreases synthesis of mycolic acid
Neurotoxic and hepatotoxic
("INH Injures neurons and hepatocytes")
What is the MOA of rifamycins? What are the two drugs in this class?
Rifampin and rifabutin
Inhibits DNA dependent RNA pol
What are the major side effects of Rifampin?
Red/orange body fluids
"RifAMPin RAMPS up p450"
What are the "3 R's" of rifampin?
-RNA pol inhibitor
-Ramps up p450s
What major side effect can be avoided by switching from rifampin to rifabutin?
Avoid p450 induction--useful for AIDS pts
What is the MOA of pyrazinamide? Toxicities?
What is the MOA of ethambutol? Toxicities?
-Decrease carb polymerization of mycobacterium walls
Optic neuropathy (red-green color blindness)
What is the TB drug that causes color blindness? Orange/red secretions?
Color blindness = ethambutol
Orange/red secretions = Rifampin
What is the antibiotic of choice for prophylaxis against: endocarditis?
What is the antibiotic of choice for prophylaxis against: Gonorrhea?
What is the antibiotic of choice for prophylaxis against: UTIs?
What is the antibiotic of choice for prophylaxis against: Meningococcal infx?
What is the antibiotic of choice for prophylaxis against: GBS for pregnant women?
What is the antibiotic of choice for prophylaxis against: Gonococcal/chlamydial infx in children?
What is the antibiotic of choice for prophylaxis against: Post surgical S. Aureus infx?
What is the antibiotic of choice for prophylaxis against: strep pharyngitis?
What is the antibiotic of choice for prophylaxis against: Syphilis
What is the antibiotic of choice for prophylaxis against: pneumocystis in AIDS pts? What is the CD4 count for this?
Less than 200
What is the antibiotic of choice for prophylaxis against: MAC in AIDS pts? What is the CD4 count for this?
Less than 50
What is the antibiotic of choice for: VRE?
What is the antibiotic of choice for MRSA?
Vanco or daptomycin
What is the MOA of amp B?
Binds to ergosterol to make membrane leaky
"amphoTERicin TEArs holes"
What is the MOA of nystatin? Clinical use?
Binds to ergosterol to make membrane leaky
What is the MOA of azoles? Toxicities?
Inhibits ergosterol synthesis
Testosterone synthesis inhibition
What is the MOA of flucytosine? Toxicities?
-Inhibits DNA and RNA biosynthesis by conversion of to 5-FU by cytosine deaminase
What is the suffix of echinocandins? MOA? Toxicities?
-Inhibits cell wall synthesis of beta-glucan
What is MOA of terbinafine? Use? Toxicity?
Inhibits squalene epoxidase
What is MOA of Griseofulvin? Use? Toxicity?
Inhibits microtubule assembly
Oral treatment of superficial fungal, infx
Increases Warfarin metabolism
What is the treatment for toxoplasmosis?
What is the treatment for Trypanosoma brucei?
Suramin and melarsoprol
What is the MOA of Chloroquine? Use? Toxicity?
Blocks detoxification of heme into hemozoin
Plasmodial species BESIDES falciparum
What are the two neuraminidase inhibitors against the flu?
What is the MOA of ribavirin? Use?
Inhibits synthesis of guanine by inhibits inosine monophosphate dehydrogenase
What is the MOA of acyclovir, famciclovir, and valacyclovir? Use?
Phosphorylated by thymidine kinase
What is the MOA of resistance against acyclovir, famciclovir, and valacyclovir?
Mutated thymidine kinase
What is the MOA of ganciclovir? Use
Guanosine analogue that inhibits DNA pol
What is the MOA of foscarnet? Use?
Viral DNA pol inhibitor that does NOT require activation by a kinase
Severe CMV infection--given IV
What is the MOA of resistance against Foscarnet?
Mutated DNA polymerase
What is the MOA of cidofovir? Use? Toxicity?
Inhibits DNA pol
What is the common suffix for HIV protease inhibitors? Toxicities?
What is the MOA of zidovudine?
What is the MOA of abacavir?
What is the general MOA of NRTIs?
Competitively inhibit nucleotide binding to reserve transcriptase
What is the only NRTI that does not need to be phosphorylated prior to action?
Tenofovir is a nucleoTide
What are the three NNRTIs? MOAs?
Binds to reverse transcriptase at a non-active site
What is the MOA of raltegravir?
Inhibits HIV genome integration into host cell chromosome by inhibiting HIV integrase
What is the MOA of enfuvirtide?
BInds gp41, inhibiting viral entry
What is the MOA of Maraviroc?
binds CCR5 on T cell surface, inhibiting gp120
What is the use of interferon-alpha? (4)
Hep B and C
hair cell leukemia
What is the use of IFN-beta?
What is the use of IFN-gamma?
Chronic granulomatous disease