4/3 micro Flashcards
Which cardiac abnormality causes wide & fixed splitting?
ASD
In cardiac splitting of S2: which sound comes last?
pulm. valve closing.
systolic ejection murmur that inc. in intensity w/standing.
hypertrophic cardiomyopathy
abrupt standing: how does this affect cardiac parameters?
- dec. preload.
- dec. afterload.
What gets converted to propionyl coa?
-mnemonic?
VOMIT pathway:
- valine
- odd chain FA
- methionine
- isoleucine
- threonine
glucocorticoids effect on glycogen in liver:
glycogenesis!
-you would think glycogenolysis, but nope!
fenoldopam
- mech?
- ues?
- dopamine D-1 receptor agonist. Dec. BP & inc. natriuesis.
- hypetensive emergencies.
Cephalosporins
- What do they not cover?
- Whats the one exception?
LAME
- listeria
- atypicals
- MRSA (except ceftaroline)
- enterococci
Only cephalosporin to kill MRSA:
ceftaroline.
1st generation cephalos:
- name them?
- coverage?
- mnemonic:
- cefazolin, cephalexin.
- PEcK
- Proteus
- E.coli
- Klebsiella
2nd gen cephalos
- coverage?
- mnemonic?
HEN PEcKS
- H. influenzae
- enterobacter
- neisseria
- proteus
- E.coli
- klebsiella
- serratia
Ceftriaxone
- which gen. cephalo?
- uses?
- 3rd gen.
- meningitis and gonorrhea.
Ceftazidime
- which gen. cephalo?
- uses?
- 3rd gen.
- Pseudomonas.
Cefepime
- which gen. cephalo?
- uses?
- 4th gen.
- Pseudomonas.
ceftaroline
- which gen. cephalo?
- uses?
- 5th gen.
- MRSA.
Which cephalos target pseudomonas?
-mnemonic?
CeftazaDIME & cefe”PRIME” = the girl in the tub in the pseudomonas vid was a DIME piece, super PRIME.
Cephalos
-tox:
- vitamin K deficiency.
- nephrotoxicity of aminoglycosides.
Which antibiotic can cause vitamin K deficiency?
Cephalos
Which 2 antibiotic classes together are very nephrotoxic?
Cephalos & aminoglycosides.
tryptase
-marker for what?
- released by mast cells.
- marker for mast cell activation.
Aztreonam
- is it a lactam?
- sensitive to beta-lactamases?
- can you use it if you’re allergic to PCN?
- yes.
- no, not sensitive.
- yes, no cross-reactivity w/PCN.
Aztreonam
-mech:
-Prevents peptidoglycan cross-linking by binding to
penicillin-binding protein 3.
Aztreonam:
-Synergistic with:
Synergistic with aminoglycosides.
Aztreonam:
- target:
- can it target anaerobes?
- gram (-) rods.
- the specific type of PBP it binds to are only found on gram (-) rods.
- can NOT target anaerobes!
Carbapenems
- lactam?
- sensitive to beta-lactamases?
- can you use it if you’re allergic to PCN?
- yes.
- no, not sensitive.
- no, you cant.
Imipenem
- must administer w/what drug?
- why?
- Cilastatin = inhibitor of renal dehydropeptidase I
- To dec. inactivation of drug in renal tubules.
Carbapenems
-suffix?
-“penem”
Carbapenems
- tox?
- which is safest carbapenem?
- CNS toxicity (seizures).
- meropenem.
Vancomycin
- tox:
- mnemonic:
NOT trouble free
- Nephrotoxicity, Ototoxicity, Thrombophlebitis.
- red man syndrome (can largely prevent by pretreatment with antihistamines and slow infusion rate).
Linezolid
-mech:
prevent formation of 70S ribosome.
Aminoglycosides
-why cant they be used against anaerobes?
bc they req. O2 for uptake.
Aminoglycosides
-mnemonic for names & tox:
mean GNATS caNNOT kill anaerobes!
- gentamicin
- neomycin
- amikacin
- tobramycin
- streptomycin
- nephrotoxic (esp. w/cephalos)
- NMJ blockade
- ototoxicity
- teratogen
*cant kill anaerobes.
Aminoglycosides
-mech:
-Inhibit formation of initiation complex and cause misreading of mRNA. Also blocks translocation.
Aminoglycosides
- ototoxicity is worse when used w/what?
- nephrotoxicity is worse when used w/what?
- oto = loop diuretics.
- neph = cephalosporins.
Aminoglycosides
-mech of resistance?
Bugs conjugate the drug so its eliminated faster than it can work.
-using transferase enzymes.
Tetracyclines
- coverage?
- mnemonic:
May Cause Rough Bite
- mycoplasma
- chlamydia
- ricketsia
- borrelia burgdorferi
Tetracyclines
- mech:
- what inhibits its absorption?
- prevents binding of tRNA to A site.
- divalent cations inhibit its absorption in the gut. Its a chelator.
Tetracyclines
-tox:
- Discoloration of teeth and inhibition of bone growth in children, photosensitivity.
- teratogen.
Tetracyclines
-mech of resistance:
Plasmid-encoded transport pumps.
Macrolides
-how to recognize?
-“thro mycin”.
Which macrolide is NOT a P450 inhibitor?
azithromycin.
Macrolides
- mech:
- which part of ribo does it bind?
-Blocking translocation (“macroslides”); bind to the 23S rRNA of the 50S ribosomal subunit.
Macrolides
- coverage:
- mnemonic?
"blew out MCL during "slide". Soccer ball represents gram (+) cocci. M=mycoplasma C=chlamydia L=legionella *Its also atypical to blow your MCL out in soccer - atypical pneumonias
Macrolides
- tox:
- mnemonic:
MACRO
- motility (binds to motilin receptors).
- arrythmia (QT prolongation).
- cholestatic hepatitis
- rash
- eOsinophilia
Macrolides
-mech of resistance:
Methylation of 23S rRNA-binding site prevents binding of drug.
linezolid
-tox:
bone marrow suppression (esp. platelets).
Chloramphenicol
- coverage?
- tox?
- mnemonic?
GRAM
- grey baby syndrome
- ricketsia
- aplastic anemia
- meningitis
Chloramphenicol
- mech:
- mech of resistance?
- Blocks peptidyltransferase at 50S ribosomal subunit.
- Plasmid-encoded acetyltransferase inactivates the drug.
Clindamycin
- mech: (same as which other drug)?
- mech of resistance?
-Blocks peptide transfer (translocation) at 50S
ribosomal subunit.
-same as macrolide.
-Methylation of 23S rRNA-binding site prevents binding of drug.
Clindamycin
- coverage?
- mnemonic?
- linDAA has GAS. AAD = anaerobes above diaphragm.
- GAS = group A strep, also reminds you about psuedomembranous colitis.
Sulfonamides
- mech?
- bacteriocidal or static?
- PABA antimetabolites inhibit dihydropteroate synthase.
- bacteriostatic! (stops it from growing, doesn’t kill it).
Sulfonamides
- coverage?
- tox?
- mnemonic?
CUNG HANK
- chalmydia
- UTI
- nocardia
- gram +/-
- hemolysis in G6PD def.
- albumin displaced
- nephrotoxic
- kernicterus
Babies w/E.coli or GBS meningitis (or any E.coli infection) should NOT be treated _____.
-why?
sulfondamides
-can cause kernicterus in kids by displacing unconjugated bili from albumin.
which bilirubin is complexed w/albumin?
indirect bili.
TMP-SMX
-bacteriostatic or cidal?
static
TMP
- tox:
- mnemonic:
Treats Marrow Poorly.
-Megaloblastic anemia, leukopenia, granulocytopenia. (May alleviate with supplemental folinic acid).
Fluoroquinolones
-suffix?
-oxacin.
Fluoroquinolones
- mech?
- cidal or static?
- dont take it with what drug?
- Inhibit DNA gyrase (topoisomerase II) and topoisomerase IV.
- Bactericidal.
- Must not be taken with antacids.
If you’re on antacids, which ABx should you NOT take?
Fluoroquinolones
nalidixic acid
-what is it?
a quinolone
Fluoroquinolones
- C/I in which pts?
- tox:
- mnemonic:
- children not done w/growth spurt, nursing mothers, pregnant women.
- Fluoroquinolones hurt attachments to your bones.
- tendonitis, tendon rupture, leg cramps, and myalgias.
- some prolong QT interval & can cause torsades bc they interefere w/ions like Calcium.
Which two ABxs can cause QT prolongation and possible torsades?
-which one more associated with this?
Macrolides & fluoroquinolones.
-macrolides.
Fluoroquinolones
-tendon rupture risk inc. w/concurrent use of what drug?
prednisone.
Metronidazole
-mech:
-Forms free radical toxic metabolites in the bacterial cell that damage DNA. Bactericidal, antiprotozoal.
Metronidazole
- targets?
- mnemonic?
GET GAP on the Metro
- giardiasis
- entamoeba histolytica
- trichomonas vaginalis
- gardnerella vaginalis
- anaerobes below diaphragm (C. dif, bacteroides).
- h. Pylori
Metronidazole
- tox:
- mnemonic:
- you’re on a metal (metallic taset) metro-train and you get car sick (disulfiram).
- metallic taste, disulfiram like reaction.
M. avium–intracellulare
-Tx:
Azithromycin or clarithromycin + ethambutol.
*Can add rifabutin or ciprofloxacin.
M. leprae
-Tx:
Long-term treatment with dapsone and rifampin for tuberculoid form.
-Add clofazimine for lepromatous form.
M. tuberculosis
-prophylaxis?
isoniazid + B6
Isoniazid (INH)
- mech:
- what does it need to be activated?
- Inhibit synthesis of mycolic acids.
- Bacterial catalase-peroxidase (encoded by KatG) needed to convert INH to active metabolite.
Which TB med is a prodrug?
-what does it need to be activated?
- Bacterial catalase-peroxidase (encoded by KatG) needed to convert INH to active metabolite.
- pyrazinamide is also a prodrug.
Isoniazid (INH)
- how is it metabolized?
- whats special about this?
- what other drugs are metabolized this way?
- isoniazid, dapsone, hydralazine, procainamide = all metabolizes thru acetylation.
- slow/fast acetylators: can get bimodal distribution graph.
Isoniazid (INH)
-effect on P450 system:
Inhibitors P450 system.
Isoniazid (INH)
- tox:
- mnemonic:
INH Injures Neurons and Hepatocytes.
- Neurotoxicity, hepatotoxicity, drug-induced lupus.
- B6 def => peripheral neuropathy.
What type of anemia can isoniazid lead to?
-why?
- B6 deficiency.
- Can’t build heme w/o B6. You’ll get sideoblastic anemia. The RBCs will be made w/o Iron. So you will get inc. serum iron.
Rifamycins
-mech:
-Inhibits DNA-dependent RNA polymerase.
Rifamycins
-prophylaxis for which bugs?
H. influenza, N. meningitidis.
Rifamycins
- which two drugs?
- which one inc. P450?
- which one favored in HIV pts?
rifampni, rifabutin.
- rifampin ramps up P450, rifabutin does not.
- Rifabutin favored over rifampin in patients with HIV infection due to less cytochrome P-450 stimulation.
Pyrazinamide
-mech:
- acidify intracellular environment.
- Effective in acidic pH of phagolysosomes, where TB engulfed by macrophages is found.
Pyrazinamide
-tox:
Hyperuricemia, hepatotoxicity.
which TB drug can cause gout?
Pyrazinamide can cause hyperuricemia.
Ethambutol
-mech:
Inhibit carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferase.
*like a beta-lactam but for TB cell wall.
Ethambutol
- tox:
- mnemonic:
Ethambutol sounds like ethanol. Arabs drink lots of ethanol. When you’re hammered you cant see straight.
- Arabs dont celebrate christmas (no red/green).
- Optic neuropathy (red-green color blindness).
Endocarditis with surgical or dental procedures
-pophylaxis:
PCN
Meningococcal infection
-pophylaxis:
Ciprofloxacin (drug of choice), rifampin for children.
Pregnant woman carrying group B strep
-prophylaxis:
ampicillin.
Prevention of postsurgical infection due to S. aureus:
Cefazolin
Prophylaxis of strep pharyngitis in child with
prior rheumatic fever:
PCN
Syphilis
-prophylaxis
Benzathine penicillin G
pentamidine
-can treat what?
pneumocystis jirovecci
Which ABxs can treat MRSA?
- vancomycin
- daptomycin
- linezolid (can cause serotonin syndrome)
- tigecycline
- ceftaroline
Which ABxs can treat VRE?
- linezolid
- streptogramins (quinupristin/dalfopristin).
Daptomycin
- mech?
- targets?
- what inactivates it?
- Bacteriocidal against almost all gram (+) bacteria.
- creates transmembrane channels which disrupts the membrane. Fucks up the membrane potential. Leaking ions.
- inactivated by pulmonary surfactant, so cant treat pneumonias
- cant penetrate outer membrane, so cant treat gram negatives.
Daptomycin
-tox:
-Associated w/myopathy. CK levels checked periodically.
surfactant inactivates which ABx?
Daptomycin
linezolid
- mech:
- targets:
- bacteriostatic.
- inhibits protein synth by binding to 50S subunit.
linezolid
-tox:
- Occasionally linked to bone marrow suppression.
- neuritis.
- Can have MAO inhibitory actions as well, so watch out if you take it w/SSRI = could get serotonin syndrome.
wolff parkinsons white
-PR interval:
-QRS complex:
are they inc or dec?
- PR interval dec.
- QRS complex widened.
Brocas
-which lobe?
frontal lobe
beta-blocker OD
-tx?
glucagon
-by increasing cAMP.
isoproterenol
-whats it do?
nonspecific beta agonist.
How is digoxin cleared?
Renally.
sickle cell
-whats the substitution?
valine put in for glutamic acid at residue 6.
Hartnup disease
-whats the problem?
Deficiency in neutral AA absorption in kidney & gut.
- ie. tryptophan (which is used to make serotonin, niacin, & melatonin).
- results in B3 (niacin) deficiency => photosensitivity & pellagra like skin rashes.
tocopherol
-what is it?
vitamin E
tocotrienol
-what is it?
vitamin E
GLUT-2
- high or low Km?
- high or low capacity?
- which tissues?
- high Km
- high capacity
- liver, pancreatic B-cells, renal tubular cells, small intestine.
In which situation will you see acyclovir nephrotoxicity?
Young HSV-1 encephalitis pt hospitalized receiving IV acyclovir.
Which sexual development disorder can present w/virilization of the mother in utero?
aromatase deficiency.
*placenta has aromatase. Thats why a 21-hydroxylase def. or anything like that would not lead to maternal virizilation. The placental aromatase would handle those excess androgens.
Amphotericin B
-what do you have to supplement this drug with?
-Supplement K+ and Mg2+ because of altered renal tubule permeability.
Amphotericin B
-commonly used w/which other drug?
flucytosine
Amphotericin B
- tox?
- how to dull some of the toxic effects?
- Fever/chills, hypotension, nephrotoxicity, arrhythmias, IV phlebitis.
- suppression of EPO synth => anemia.
- Hydration dec. nephrotoxicity.
- Liposomal amphotericin dec. toxicity.
Azoles
-mech:
- Inhibit 14–α–demethylase which converts lanosterol to ergosterol.
- its a P450 enzyme!
Azoles
-which is only azole that crosses BBB?
fluconazole
topical fungal infections
-which anti-fungals?
Clotrimazole and miconazole.
-aka clotrimin-ultra.
Azoles
-tox:
- Testosterone synthesis inhibition = a P450 enzyme makes testosterone.
- gynecomastia (esp. with ketoconazole)
- liver dysfunction = inhibits cytochrome P-450.
What other random drug had anti-androgen effects like the azoles?
spironolactone
How does ketoconazole produce anti-androgen effects?
Inhibits desmolase which converts cholesterol to pregnenolone - one of first steps of steroid synthesis.
-will reduce androgens as well as cortisol.
How does spironolactone produce anti-androgen effects?
1) Inhibits desmolase which converts cholesterol to pregnenolone - one of first steps of steroid synthesis.
- will reduce androgens as well as cortisol.
2) inhibits steroid binding.
3) inhibits 17alpha-hydroxlase.
How do spironolactone and ketoconazole lead to amenorrhea?
No androgens means no estrogens.
-no estrogen = no menses.
Flucytosine
- what is it?
- mech?
- Inhibits DNA and RNA biosynthesis => anti-fungal.
- converted to 5-FU by cytosine deaminase.
- 5-FU inhibits thymidilate synthase.
Flucytosine
-use?
Systemic fungal infections (esp. meningitis caused by Cryptococcus) in combination with amphotericin B.
Echinocandins
-suffix?
-fungin.
Echinocandins
- mech?
- mnemonic:
Inhibits cell wall synthesis by inhibiting synthesis of β-glucan.
-echinocanDIN(ner) - ends w/GIN: Glucan INhibitor.
Echinocandins
- target?
- mnemonic:
- Invasive aspergillosis, Candida.
- C-AS-pofungin: C=candida, AS=aspergillosis.
Echinocandins
-tox:
GI upset, flushing (by histamine release).
Terbinafine
- mech:
- mnemonic:
-Inhibits the fungal enzyme squalene epoxidase. Part of ergosterol synth pathway.
“Use epoxy glue to fix the turbine. They were squeeking.”
Terbinafine
-use:
Dermatophytoses (especially onychomycosis—fungal infection of finger or toe nails).
Terbinafine
- tox:
- mnemonic:
- hepatotoxicity, taste disturbance.
- think of turbines in nose and associate w/taste impairment
Griseofulvin
- mech:
- mnemonic:
Interferes with microtubule function. Deposits in keratin-containing tissues.
-Grease up the MTs.
Griseofulvin
-use:
Oral treatment of superficial infections; inhibits growth of dermatophytes (tinea, ringworm).
Griseofulvin
-tox:
Teratogenic, carcinogenic, confusion, headaches, inc. P-450 and warfarin metabolism.
Besides the azoles, which other antifungal inc. P450 system?
griseofulvin.
“greasy”
