Copy of Micro ID - Sheet1 Flashcards
Penicillin G
1) Gram-positive organisms (S. pneumoniae, S. pyogenes, Actinomyces), n meningitis, t pallidium (syphillis); Bactericidal for gram-positive cocci, gram-positive rods, gram-negative cocci, & spirochetes; Not penicillinase resistant
2) IV/im Penicillin (Prototype Beta-lactam abx;Non-penicillinase resistant); Bind PNC-binding proteins (transpeptidase); Block transpeptidase cross-linking of peptidoglycan; Activates autolytic enzymes
3) Hypersensitivity rxns; Hemolytic anemia
4) Resistance: Beta-lactamases cleave Beta-lactam ring
Penicillin V
1) Gram-positive organisms (S. pneumoniae, S. pyogenes, Actinomyces), n meningitis, & t pallidum (syphillis); Bactericidal for gram-positive cocci, gram-positive
rods, gram-negative cocci, & spirochetes; Not penicillinase resistant
2) PO Penicillin (Prototype Beta-lactam abx;Non-penicillinase resistant); Bind PNC-binding proteins (transpeptidases); Block
transpeptidase cross-linking of peptidoglycan; Activates autolytic enzymes
3) Hypersensitivity rxns; Hemolytic anemia
4) Resistance: Beta-lactamases cleave Beta-lactam ring
Methicillin
1) S. aureua (except MRSA; resistant d/t altered PNC-binding protein target site)
2) PEnicillinase-Resistant PNCs; Bind PNC-binding proteins; Block
transpeptidase cross-linking of peptidoglycan; Activates autolytic enzymes (=Same MOA as PNC). Narrow spectrum; Penicillinase resistant b/c of bulkier R-group
3) Hypersensitivity rxns; Interstitial nephritis (Methicillin specific)
Nafcillin, oxacillin, dicloxacillin
1) S. aureua (except MRSA; resistant d/t altered PNC-binding protein target site)
2) PEnicillinase-Resistant PNCs; Bind PNC-binding proteins; Block
transpeptidase cross-linking of peptidoglycan; Activates autolytic enzymes (=Same MOA as PNC). Narrow spectrum; Penicillinase resistant b/c of bulkier R-group
3) Hypersensitivity rxns
4) Use naf for staph!
Ampicillin, amoxicillin
1) Extended-spectrum PNC–Haemophilus influenza, E. Coli, Listeria monocytogenes, Proteus mirabilis, Salmonella, Shigella, enterococci (HELPSS kill enterococci)
2) AminoPNCs; Bind PNC-binding proteins; Block
transpeptidase cross-linking of peptidoglycan; Activates autolytic
enzymes (=Same MOA as PNC). Wider spectrum; Penicillinase sensitive. Also combine w/ clavulonic acid to protect against Beta-lactamase; amoxicillin has greater oral bioavailability than ampicillin
3) Hypersensitivity rxs; Ampicillin rash; Pseudomemranous colitis
4) Resistance: Beta-lactamases cleave Beta-lactam ring
Ticarcillin, piperacillin
1) Pseudomonas spp. & gram-negative rods; Susceptible to penicillinase; Use w/ Clavulonic acid (to protect against Beta-lactamase)
2) Antipseudomonals; Bind PNC-binding proteins; Block
transpeptidase cross-linking of peptidoglycan; Activates autolytic
enzymes (=Same MOA as PNC). Extended spectrum
3) Hypersensitivity rxns
4) TCP (Ticarcillin, Carbenicillin, & Piperacillin)–Takes Care of Pseudomonas
Carbenicillin
1) Pseudomonas spp. & gram-negative rods; Susceptible to
penicillinase; Use w/ Clavulonic acid (to protect against Beta-lactamase)
2) Antipseudomonals; Bind PNC-binding proteins; Block
transpeptidase cross-linking of peptidoglycan; Activates autolytic
enzymes (=Same MOA as PNC). Extended spectrum
3) Hypersensitivity rxns
4) TCP (Ticarcillin, Carbenicillin, & Piperacillin)–Takes Care of Pseudomonas
Clavulonic Acid, sulbactam, tazobactam
1) Often added to PNC abxs to protect the abx from destruction by Beta-lactamase (penicillinase)
2) Beta-lactamase inhibitor
3) –
4) CAST (Clavulonic Acid, Sulbactam, & Tazobactam)
Cefazolin, cephalexin
1) Gram-positive cocci, Proteus mirabilis, E. Coli, Klebsiella pneumoniae. **Cefazolin–used prior to surgery to prevent S. aureus wound infections.
2) Beta-lactam, 1st Generation Cephalosporins; Beta-lactam rx that inhibits cell wall synthesis but are less susceptible to penicillinases. Bactericidal
3) Hypersensitivity rxns, Vit K deficiency. Low cross-reactivity w/ Penicillins. Increased nephrotoxicity of Aminoglycosides.
4) Orgs covered by 1st Generation=PEcK–Proteus mirabilis, E. Coli, Klebsiella pneumoniae; Orgs typically not covered by Cephalosporins are LAME: Listeria, Atypicals (Chlamydia, Mycoplasma), MRSA & Enterococci. (Exception= Ceftaroline-covers MRSA)
Cefoxitin, cefaclor, cefuroxime
1) Gram-positive cocci, Haemophilus influenzae, Enterobacter aerogenes, Neisseria spp., Proteus mirabilis, E. Coli, Klebsiella pneumoniae, Serratia marcescens
2) Beta-lactam, 2nd Generation Cephalosporins; Beta-lactam rx that inhibits cell wall synthesis but are less susceptibl to penicillinases. Bactericidal
3) Hypersensitivity rxns, Vit K deficiency. Low cross-reactivity w/ Penicillins. Increased nephrotoxicity of Aminoglycosides.
4) Orgs covered by 2nd Generation=HEN PEcKS–Haemophilus influenzae, Enterobacter aerogenes, Neisseria spp., Proteus
mirabilis, E. Coli, Klebsiella pneumoniae, Serratia marcescens; Organisms typically not covered by Cephalosporins are LAME: Listeria,
Atypicals (Chlamydia, Mycoplasma), MRSA & Enterococci. (Exception= Ceftaroline-covers MRSA)
Ceftriaxone, cefotaxime, ceftazidime
1) Serious gram-negative infections resistant to other Beta-lactams; **Ceftriaxone–meningitis & gonorrhea
Ceftazidime=pseudomonas
2) Beta-lactam, 3rd Generation Cephalosporins; Beta-lactam rx that inhibits cell wall
synthesis but are less susceptibl to penicillinases. Bactericidal
3) Hypersensitivity rxns, Vit K deficiency. Low cross-reactivity w/ Penicillins. Increased nephrotoxicity of Aminoglycosides.
4) Organisms typically not covered by Cephalosporins are LAME: Listeria,
Atypicals (Chlamydia, Mycoplasma), MRSA & Enterococci. (Exception=
Ceftaroline-covers MRSA)
Cefepime
1) Increase activity against Pseudomonas & gram-positive orgs
2) Beta-lactam, 4th Generation Cephalosporins; Beta-lactam rx that inhibits cell wall
synthesis but are less susceptibl to penicillinases. Bactericidal
3) Hypersensitivity rxns, Vit K deficiency. Low cross-reactivity w/ Penicillins. Increased nephrotoxicity of Aminoglycosides.
4) Organisms typically not covered by Cephalosporins are LAME: Listeria,
Atypicals (Chlamydia, Mycoplasma), MRSA & Enterococci. (Exception= Ceftaroline-covers MRSA)
Ceftaroline
1) **Only Cephalosporin that covers MRSA
2) Beta-lactam, **Newest Generation Cephalosporin; Beta-lactam rx that inhibits cell wall
synthesis but are less susceptibl to penicillinases. Bactericidal
3) Hypersensitivity rxns, Vit K deficiency. Low cross-reactivity w/ Penicillins. Increased nephrotoxicity of Aminoglycosides.
4) Organisms typically not covered by Cephalosporins are LAME: Listeria,
Atypicals (Chlamydia, Mycoplasma), MRSA & Enterococci. (Exception= Ceftaroline-covers MRSA)
Ertapenem, doripenem
1) Gram-positive cocci, gram-negative rods, & anaerobes. Wide spectrum, but the significant side effects limit use to life-threatening
infections, or after other drugs have failed.
2) Beta-lactam, Newer Carbapenem; Bind PNC-binding proteins; Block transpeptidase cross-linking of peptidoglycan; Activates autolytic enzymes (=Same MOA as PNC)
3) GI distress, Skin rash, & CNS toxicity (seizures) at high plasma levels
Aztreonam
1) Gram-negative rods only–No activity against gram-positives or anaerobes. For penicllin-allergic pts & those w/ renal insufficiency who cannot tolerate aminoglycosides
2) Beta-lactam, Monobactam; Resistant to Beta-lactamases. Prevents peptidoglycan cross-linking by binding to PBP3. Synergistic w/ Aminoglycosides. No cross-allergenicity w/ Penicillins.
3) Usually nontoxic; Occasional GI upset
Imipenem (w/ Cilastatin), meropenem
1) Gram-positive cocci, gram-negative rods, & anaerobes. Wide spectrum, but the significant side effects limit use to life-threatening
infections, or after other drugs have failed. *Meropenem, however, has a reduced risk of seizures & is stable to dehydropeptidase I.
2) Beta-lactam, Carbapenem; *Imipenem–broad-spectrum, Beta-lactamase-resistant carbapenem. Bind PNC-binding proteins; Block
transpeptidase cross-linking of peptidoglycan; Activates autolytic enzymes (=Same MOA as PNC). **Always administered w/ Cilastatin (inhib of renal dehydropeptidase I) to decrease inactivation of drug in renal tubules.
3) GI distress, Skin rash, & CNS toxicity (seizures) at high plasma level
Vancomycin
1) Gram-positive only–serious, amultidrug-resistant orgs, including MRSA, enterococci, & C. difficile (oral dose for pseudomembranous colitis)
2) Antimicrobial; Inhib cell wall peptidoglycan formation by binding D-ala D-ala portion of cell wall precursors. Bactericidal.
3) Nephrotoxicity, Ototoxicity, Thrombophlebitis, diffuse flushing–red man syndrome (can largely prevent by pretreatment w/ antihistamines & slow infusion rate). Well tolerated in general (–does NOT have many problems)
4) Resistance: Occurs w/ amino acid change of D-ala D-ala to D-ala D-lac. [“Pay back 2 D-alas (dollars) for VANdalizing (VANcomycin)]
Streptomycin, gentamicin, neomycin, amikacin, tobramycin
1) Severe gram-negative rod infections. Synergistic w/ Beta-lactam Abs. Neomycin for bowel surgery
2) Aminoglycosides; Bactericidal. Inhibits formation of initiation complex (30s) & cause misreading of mRNA. Also block translocation. Req O2 for uptake; therefore, ineffective against anaerobes. (A “initiates” the Alphabet)
3) Nephrotoxicity (acute tubular necrosis, esp when used w/ Cephalosporins), Neuromuscular blockade, Ototoxicity (esp when used w/ Loop diuretics). Teratogen.
4) Resistance: Transferase enzymes that inactivate the drug by acetylation, phosphorylation, or adenylation.
4) Aminoglycoside Rxs & ADES: “MEAN”=(aMINoglycosides) GNATS caNNOT kill anaerobes–Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin, Nephrotox, Neuromuscular blockade, Ototoxicity, Teratogen
Minocycline, tetracycline, doxycycline, demeclocycline
1) Borrelia burgdorferi, M. pneumoniae. Drug’s ability to accumulate intracellularly makes it very effective against Rickettsia & Chlamydia.
2) Tetracyclines; Bacteriostatic. Bind to 30S & present attachment of aminoacyl-tRNA to a site; Limited CNS penetration. Doxycycline fecally eliminated & can be used in pts in renal failure. Do not take w/ milk, antacids, or iron-containing preparations b/c divalent cations inhib its absorption in the gut
3) GI distress, Discoloration of teeth & inhib of bone growth in children, Photosensitivity. Contraindicated in pregnancy.
4) Resistance: Decreased uptake into cells or Increased efflus of cell by plasmid-encoded transport pumps.
Demeclocycline=AdH antagonist; acts as diuretic in siadh; rarely used as abx
Erythromyci, azithromycin, clarithromycin
1) Atypical pneumonias (Mycoplasma, Chlamydia, Legionella), STDs (for Chlamydia), & gram-positive cocci (Strep infections in pts allergic to penicillins)
2) Macrolides; Inhib protein synth by blocking translocation; Bind to 23S rRNA of 50S ribosomal subunit. Bacteriostatic.
3) Motility issues, Arrhythmia caused by prolonged QT, acute Cholecstatic hepatitis, Rash, eOsiniphilia (=MACRO). Increases serum concentration of theophyllines, oral anticoagulants.
4) Resistance: Methylation of 23S rRNA binding site.
Chloramphenicol
1) Meningitis (Haemophius influenzae, Neisseria meningitidis, Streptococcus pneumoniae). Conservative use d/t toxicities but often still used in developing countries b/c of low cost
2) Protein Synthesis Inhib; Blocks peptidyltransfease (transfers trna from a to p and formation of peptide bond) at 50s ribosomal subunit. Bacteriostatic
3) Anemia (dose dep), Aplastic aneima (dose dep), Gray baby syndrome (in premature infants b/c lack liver UDP-glucuronyl transferase)
4) Resistance: Plasmid-encoded acetyltransferase that inactivates drug
Clindamycin
1) Anaerobic infections (e.g., Bacteroides fragilis, Clostridium perfringens) in aspiration pneumonia or lung abscesses. Also oroal infections w/ mouth anaerobes.
2) Protein Synthesis Inhib; Block peptide transfer (transpeptidation at 50s ribosomal subunit. Bacteriostatic.
3) Pseudomembranous colitis (C. dificile overgrowth), fever, diarrhea.
4) Clindamycin tx anaerobes ABOVE the diaphragm vs Metronidazole (which tx anaerobes BELOW the diaphragm)
Sulfadiazine, sulfamethoxazole (SMX), sulfisoxazole
1) Gram-positive, gram-negative, Nocardia, Chlamydia. Triple sulfas or SMX for simple UTI.
2) Sulfonamides; PABA antimetabolites inhib dihydropteroate synthase. Bacteriostatic.
3) Hypersensitivity rxns, Hemolysis if G6PD deficient, Nephrotoxicity
(tubulointerstitial nephritis), Photosensitivity, Kernicterus in
infants, Displace other drugs from albumin (e.g. Warfarin)
4) Resistance: Altered enzyme (bacterial dihydropteroate synthase), Decreased uptake, or Increased PABA synthesis
Trimethoprim (TMP)
1) Used in combo w/ sulfonamides [trimethoprim-sulfamethoxazole (TMP-SMX)], causing sequential block of folate synth. This combination is used to tx: UTIs, Shigella, Salmonella, Pneumocystic jirovecii pneumonia (tx & prophylaxis)
2) Inhib bacterial dihydrofolate reductase. Bacteriostatic
3) Megaloblastic anemia, leukopenia, granulocytopenia. [May alleviate w/ supplemental folinic acid (=Leucovorin rescue)]
4) TMP–Treats Marrow Poorly
Ciprofloxacin, norfloxacin, levofloxacin, ofloxavin, sparfloxacin, moxifloxacin, gatifloxacin, enoxacin (fluroquinolones) & nalidixic acid (quinolone)
1) Gram-negative rods of urinary & GI tracts (including Pseudomonas), Neisseria, some gram-positive orgs
2) fluroquinolones Inhib DNA gyrase (topoisomerase II) & topoisomerase IV. Bacterocidal. Must not be taken w/ antacids. Leads to torsional stress fractures of chromosomes)
3) GI upset, hypoglycemia, Super infections, Skin rashes, headache, Dizziness. Less comonly–tendonitis, tendon rupture (achilles in kids), leg cramps, & myalgias. Contraindicated in–pregnant women & children b/c animal studies show damage to cartilage. Some may cause prolonged QT interal. May cause tendon rupture in ppl >60 yo & in pts taking Prednisone.
4) Resistance: Chromosome-encodede mut in DNA gyrase, plasmid-mediated resistance, efflux pumps
Metronidazole
1) Txs Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (Bacteroides, C. dificile). Used w/ proton pump inhib & Clarithromycin for “triple therapy” against H. Pylori (GET GAP on the Metro w/ metronidazole! Tx anaerobes below diaphragm, clindamycin tx above)
2) Forms free radical toxic metabolites in the bacterial cell that damage DNA. Bactericidal, antiprotozoal
3) Disulfuram-like rxn w/ alcohol; headache, Metallic taste
Antimicrobial Drugs: Prophylaxis & Tx
- M. tuberculosis
- M. avium-intracelluare
- M. leprae
Antimicrobial Drugs: Prophylaxis & Tx
- M. tuberculosis–Prophylaxis=Isoniazid & Tx=Rifampin, Isoniazid, Pyrazinamide, Ethambutol (RIPE for tx)
- M. avium-intracelluare–Prophylaxis=Azithromycin & Tx=Azithromycin, Rifampin, Ethanobutol, Streptomycin
- M. leprae–Prophylaxis=N/A & Tx=Long-term tx w/ Dapsone & Rifampin for tuberculoid form. Add Clofazimine for lepromatous form.
Isoniazid (INH)
1) Mycobacteriium tuberculosis; Only drug used as solo prophylaxis against TB
2) Antimicrobial; Decreases synth of mycolic acids. Bacterial catalase-peroxidases (KatG) needed to convert INH to active metabolite
3) Neurotoxicity (peripheral neuropathy), Hepatotoxicity, cyp 450 inhib. Pyridoxine (vit B6) can prevent neurotoxicity, lupus (INH–Injures Neurons & Hepatocytes)
4) Different INH half-lives in fast vs slow acetylator
Chemically sim to pyridoxine (b6)–>depleted during inh tx
Rifampin
1) Mycobacterium tuburculosis; Delays resistance to dapsone (se=agranulocytosis) when used for leprosy. Used for meningococcal prophylaxis and chemoprophylaxis in contacts of children w/ Haemophilus influenzae type B
2) Antimicrobial; Inhib DNA-dep RNA polymerase (prevent transcription)
3) Minor hepatotoxicity & drug rxns (increased P-450); Orange body fluids (nonhazardous side effect)
4) 4 Rs–RNA polymerase inhib, Revs up microsomal P-450, Red/orange body fluids, Rapid resistance if used alone (alt structure of polymerase)
Pyrazinamide
1) Mycobacterium tuberculosis
2) Antimicrobial; Mech unknown–thought to acidify intracellular env via conversion to pyrazinoic acid. Effective in acidid pH of phagolysosomes, where TB engulfed by macs is found
3) Hyperuricemia, Hepatotoxicity
