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126 Cards in this Set
- Front
- Back
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What is nitrofurantoin used for?
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UTIs that are NOT caused by PP --> Proteus and Pseudomonas.
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What is a side effect of nitrofurantoin?
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Can cause brownish discoloration of urine --> because it is metabolized and excreted by kidney.
2) allergic pulmonary infiltrates 3) Lupus like syndrome 4) G6PD-deficiency: hemolytic anemia |
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What is the mechanism of action of TMP?
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Inhibits bacterial dihydrofolate reductase, so it is a bacteriostatic!
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What is TMP-SMX used for?
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Recurrent UTIs and PCP Pneumonia.
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What are the side effects of TMP-SMX?
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Treats the marrow poorly
1) G6PD deficiency 2) megaloblastic anemia 3) leukopenia 4) granulocytopenia, neutropenia |
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What are some examples of sulfonamides?
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Sulfamethoxazole (SMX), sulfisoxazole, triple sulfas, and sulfadiazine.
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What is the mechanism of action of sulfonamides?
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Inhibits dihydropteroate synthase, preventing formation of dihydropteroid acid so cant make dihydrofolic acid. It is a bacteriostatic
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What are sulfonamides used for?
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Treat Nocardia, Chlamydia, simple UTIs.
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What are side effects of sulfonamides?
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Hypersensitivity reactions, hemolysis if G6PD deficient.
2) Nephrotoxicity (tubulointerstitial) 3) kernicterus in infants 4) Can displace drugs from albumin (warfarin) 5) Steven-Johnson syndrome |
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What are fluoroquinones?
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Antibiotics that inhibit topoisomerae II (DNA gyrase) and topoisomerase IV, causing termination of DNA replication.
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What are quinolones?
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They are 1st generation and consist of nalidixic acid.
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What is nalidixic acid used for?
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Used for UTIs caused by gram negative bacteria. It is a quinolone antibiotic (1st generation)
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What are the 2nd generation fluoroquinolones?
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Norfloxacin, Oflaxacin, and Ciprofloxacin.
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What are teh side effects of nalidix acid? (1st generation quinolone)
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Seizures, anaphylaxis,
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What are the 3rd generation fluoroquinolones?
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Levofloxacin, gatifloxacin, and moxifloxacin
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What are the 2nd generation fluoroquinolones?
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Norfloxacin, oflaxacin, ciprofloxacin
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What are the 3rd generation fluoroquinolones?
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Levofloxacin, gatifloxacin, and moxifloxacin. used as "respiratory quinolones"
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What is the 4th generation fluoroquinolone?
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Trovafloxacin
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What is the side effect of trovafloxacin?
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Hepatotoxicity
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What are the general side effects of fluoroquinolones?
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1) GI upset
2) Rash, allergy, photosensitivity 3) QT prolongation 4) Chondrocyte toxicity causing impaired cartilage development, so dont give to pregnant women, breast feeding women, or children. |
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What is the mechanism of action of fluoroquinolones?
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Inhibit topoisomerase II (AKA DNA gyrase) and topoisomerase IV (causing termination of DNA replication).
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What does topoisomerase II normally do?
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Functions in negative supercoiling and elimination of supercoils at the replication fork.
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What does topoisomerase IV normally do?
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Functions in separation of daughter molecules after replication is complete.
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What are some side effects of fluoroquinolones in adults?
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Tendonitis and tendon rupture
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What are some side effects of fluoroquinolones in children?
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Leg cramps and myalgias in kids.
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What are fluoroquinolones used for?
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Gram-negative rods of urinary and Gi tracts. Used to treat UTIs and sometimes atypical respiratory bugs.
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What is the most active fluoroquinolone against Pseudomonas?
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Ciprofloxacin.
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What is mechanism of Clindamycin?
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Inhibits protein synthesis at the level of the 50S ribisome. Remember buy AT 30, CELL at 50. cLindamycin
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What is the clinical use of clindamycin?
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Used to treat anaerobic infections (Bacteroides, Clostridium).
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What is the toxicities of clindamycin?
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Pseudomembranous colitis (C. dificile overgrowth), fever, and diarrhea. It is commonly associated with this!
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What is the mechanism of action of chloramphenicol?
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It inhibits 50 S subunit of ribosome. CELL at 50! It is a bacteriostatic.
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What is chloramphenicol used for?
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Used to treat meningitis due to haemophilus, neisseria, and strep.
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What is the side effect of chloramphenicol?
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1) Aplastic anemia (dose independent)
2) Bone marrow depression: granulocytopenia, leukopenia 3) Gray baby syndrome (in premature infants because they lack liver UDP-glucuronyl transferase) |
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What is linezolid?
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Antibiotics used to treat resistant bacteria such as MRSA, VISA, and VRE
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What is unique about linezolid?
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It is a weak monoamine oxidase inhibitor, so patients should avoid tyramine rich foods and drugs with seretonergic and/or adrenergic effects.
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What are Streptogramins?
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They consist of quinopristin-dalfopristin and used in MRSA, VRE, and pencillin-resistant pneumococci.
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What is the mechanism of action of streptogramins?
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blocks 50 S ribosomal unit.
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What is the toxicity of streptogramins (quinopristin-dalfopristin)?
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Potent inhibitor P450 enzyme and increases QT interval.
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What are some examples of macrolides?
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erythromycin
azithromycin clarithrymocyin |
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What is the mechanism of macrolides (erythromycin, azithromycin, clarithromycin)
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Block 50 S ribosomal subunit. It is bacterostatic.
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What are the clinical uses of erythromycin, azithromycin, and clarithromycin?
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URIs, pneumonias, STDs: Mycoplasma, Legionella, Chlamydia, Neisseria.
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what are the side effects of macrolides?
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Gi discomfort, cholestatic hepatitis, skin rashes. All macrolides can cause ventricular tachycardia, QT prolongation, and torsades de pointes.
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What are the macrolides effect on CY P450?
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It can inhibit p450 strongly and increase serum concentration of theophyllines and oral anticoagulants.
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This class of drug blocks cell wall synthesis by inhibition of peptidoglycan cross-linking
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Penicillin, ampicillin, ticarcillin, piperacillin, imipenem, aztreonam, cephalosporins.
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These drugs block peptidoglycan synthesis (NOT block peptidoglycan cross-linking)
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Bacitracin and vancomycin
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This class disrupts bacteria/fungal cell membranes
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Polymyxins
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Blocks nucleotide synthesis
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Sulfonamides, trimethoprim
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Blocks DNA topoisomerases
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Quinolones
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This class of drug blocks mRNA synthesis
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Rifampin
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These drugs block protein synthesis at 50S ribosomal subunits
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Chloramphenicol, erythromycin/macrolides, lincomycin, clindamycin, linezolid, streptogramins (quinupristin, dalfopristin)
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Block protein synthesis at 30 S ribosomal subunit
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Aminoglycosides and tetracyclines
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Bactericidal antibiotics
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1) Penicillin
2) Cephalosporins 3) Vancomycin 4) Aminoglycosides (only one of the protein inhibitors) 5) Fluoroquinolones 6) Metronidazole |
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What is a bacteriocidal?
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Antibiotic that kills the bacteria with the host immune system NOT required for bacterial killing.
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What is a bacteriostatic?
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An antibiotic that stops the growth of the bacteria, allowing the host immune system to fight bacteria more efficiently.
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What is a transpeptidase?
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It is a penicillin-binding protein that cross links peptidoglycan subunits to the bacterial cell wall.
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What do Beta-Lactam drugs do?
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They bind to PBPs covalently and prevent its action. They also activate endogenous autolysins that degrade the cell wall.
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What is the key side effect of cell wall inhibitors?
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Allergic reaction with rash.
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What is the IV form of penicillin?
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Penicillin G
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What is the oral form of penicillin?
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Penicillin V
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What is the mechanism of penicillin?
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1) Binds transpeptidase (PBP)
2) Blocks transpeptidase cross-liking of cell wall 3) Activate endogenous autolysins |
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What are the indications for penicillin use?
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1) Gram +
2) Gram negative cocci 3) Streptococcus 4) Syphilis 5) Neisseria meningitidis 6) Clostridium specieis |
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What is the toxicity associated with penicillin use?
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Hypersensitivity reactions and hemolytic anemia.
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What is the action of probenecid?
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Inhibits renal tubular excretion of penicillin, thus increases the systemic concentration of antibitioc.
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What is the mechanism of action of methicillin, nafcillin, oxacillin?
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1) Binds Pencillin binding protein
2) inhibits its cross-linking action 3) activates endogenous autolysis 4) Penicillinase resistant because of bulkier R group. |
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What is the indication to use methicillin, nafcillin, oxacillin?
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Staph aureus. (Except MRSA: MRSA is resistant due to altered transpeptidase target site)
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What is the toxicity of methicillin?
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interstitial nephritis
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What is toxicity of nafcillin, dicloxacillin?
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Hypersensitivity reactions!
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How should Beta-lactam antibiotics be dosed in patients with renal failure?
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Almost all the Beta-lactam antibiotics are excreted by kidneys, so in patients with renal failure, the doses need to be lowered.
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What are some mechanisms of resistance to Beta-lactam?
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1) Beta-lactamase enzyme cleaving the beta-lactam ring
2) Decreases permeability of cell wall or outer membrane 3) Increased production of penicillin binding proteins. 4) Mutation of penicillin binding proteins to decrease affinity for beta-lactam ring. |
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What is the mechanism of action of ampicillin, amoxicillin?
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Same as penicillin, but also penicillinase sensitive. Must combine with clavulanic acid (penicillinase inhibitor) to enhance action
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Which has greater bioavailability ampicillin or amoxicillin?
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amOxicillin.
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When is amoxicillin used?
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Used before dental procedures for patients at risk for bacterial endocarditis.
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What is the clinical use of amoxicillin and ampicillin?
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HELPS kill enterococci
1) Haemophilus influenzae 2) E. coli 3) Listeria monocytogenes 4) Proteus mirabilis 5) Salmonella 6) Enterococci |
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Side effects of ampicillin and amoxicillin?
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Hypersensitivity reactions; ampicillin rash, and pseudomembranous colitis. Rashes and diarrhea are more common with ampicillin/amoxicillin than with other penicillins especially if given to patient with mononucleosis.
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What is the action of ticarcillin, carbenicillin, and piperacillin?
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Same as penicillin. TCP: Take care of pseudomonas?
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What is piperacillin used to treat?
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Pseudomonas
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What is carbenicillin used to treat?
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Pseudomonas
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What is tarcacillin used to treat?
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Pseudomonas
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What are the side effects of anti-pseudomonals?
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Ticarcillin, carbenicillin, and piperacillin can cause hypersensitivity, metabolic alkalosis, and platelet dysfunciton.
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What are some examples of beta-lactamase inhibitors?
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Clavulanic acid, sulbactan, tazobactam
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What is mechanism of action of clavulanic acid, sulbactam, tazobactam?
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Binds to Beta-lactamase catalytic site preventing degradation of beta-lactam antibiotics. It can also bind to PBP enhancing its action. **Note, these drugs are NOT antibacterial if used alone.
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What are cephalosporins?
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Beta-lactam drugs that inhibit cell wall synthesis but are less susceptibile to penicillinases. Bactericidal.
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What are the first generation cephalosporins?
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Cefazolin, Cephalexin
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What are the 2nd generation cephalosporins?
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Cefoxitin, Cefaclor, Cefuroxime
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What are 3rd generation cephalosporins?
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Ceftriaxone, Cefotaxime, Ceftazidime; TRI TAX TAZ
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What are some 4th generation cephalosporins?
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Cefepime, Cefpiramide
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What is indication for 1st generation cephalosporins (cefazolin, cephalexin)?
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Gram positive cocci: PEcK
1) Proteus mirabilis 2) E. coli 3) Klebsiella |
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What is indication for 2nd generation (cefoxitin, cefaclor, cefuroxime)?
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FAC that FOX has FUR
HEN PEcKs 1) Haemophilus 2) Enterobacter 3) Neisseria 4) Proteus 5) E. coli 6) Klebsiella 7) Serratia |
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Which class is th eonly active ones against Bacteroides?
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2nd generation cephalosporins (Cefoxitin, Cefotetan)
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What are the cephalosporins of choice to treat gonorrhea?
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Ceftriaxone and Cefixime
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Which of the cephalosporins can cause a disulfuram like reaction?
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Cefotetan (2nd generation)
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Which are the only cephalosporins effective against P. aeruginosa?
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Ceftazidime and cefepime
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What are some side effects of ceftriaxone?
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Gallstones and increase in PT time due to inhibition of Vitamin K-dependent clotting factor synthesis.
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What are the fourth generation drugs like cefepime and cefpiramide used for?
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Increased activity against Pseudomonas and gram-positive organisms
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What do 3rd generation cephalosporins cover?
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HEN PEcKs
1) Haemophilus influenzae 2) Enterobacter 3) Neisseria 4) Proteus 5) E.coli 6) Klebsiella 7)Serratia Can treat meningitis because most penetrate the blood-brain barrier. |
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What are the 3rd generation cephalosporins?
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Ceftriaxone, Ceftazidime, Cefotaxime.
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What is the toxicity of cephalosporins?
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Hypersensitivity reactions. Cross-hypersensitivity with penicillins in 5-10% of patients. Have increased nephrotoxicity of aminoglycosides; disulfuram-like reaction with ethanol.
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What is aztreonam?
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It is an alternative to aminoglycosides and can be used in patients with penicillin allergy. Its a synergistic effect with aminoglycosides.
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What is aztreonam used for?
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Limited to gram negative aerobes! Has no activity vs gram positive or anaerobes.
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What is the mechanism of action of aztreonam?
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Gram negative aerobes ONLY
Inhibits cell wall synthesis by binding to PBP It is resistant to B-lactamases |
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When can aztreonam be used?
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Gram negative aerobes! Can be used in patients with renal failure who cannot tolerate aminoglycosides or in patients with penicillin allergy.
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What is imipinem?
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Broad specturem, Beta-lactamase resistant carbapenem. Always administered with cilastatin to decrease inactivation in renal tubules.
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Why is cilastatin used with imipinem?
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Cilastin is an inhibitor of renal dihydropeptidase I to decrease imipinems inactivation in renal tubules.
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What is the drug of choice for Enterobacter?
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Imipinem
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What is action of imipinem?
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Broad spectrum and drug of choice for enterobacter. Reserved for serious mixed polymicrobial infections in with aerobes and anaerobes are involved.
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Toxicity of imipinem?
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Skin rash. CNS toxicity (seizures) at high plasma levels.
Remember: they are Beta-lactamase resistant! |
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What is vancomycin mechanism of action?
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Blocks peptidoglycan synthesis. It binds D-ala D-ala portion of cell wall precursors preventing peptidoglycan formation.
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How do bacteria become resistant to vancomycin?
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They change their D-ala D-ala to D-ala D-lac to prevent vancomycin binding. (i.e. Vancomycin resistant enterococci)
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What is vancomycin used for?
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Reserved for serious infections by MRSA and C. dificile. It is 2nd choice for pseudomembranous colitis.
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What is vancomycin toxicity?
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nephrotoxicity, ototoxicity, thrombophlebitis, diffuse flushing "red man syndrome"
Red man syndrome can be prevented by pretreatment with antihistamines and slow infusion rate. |
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What are the 30 S Protein inhibitors?
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Aminoglycosides (streptomycin, gentamicin, tobramycin, amikacin)
Tetracyclines (bacteriostatic) |
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Are aminoglycosides bacteriostatic or bactericidal?
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Bactericidal. Only one of the protein synthesis inhibitors that are bactericidal. --> streptomycin, gentamicin, tobramycin, amikacin.
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What are the 50 S protein synthesis inhibitors?
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Chloramphenicol,
Erythromycin (macrolides) Lincolmycin Clindamycin |
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What are some examples of aminoglycosides?
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Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin "Mean GNATS canNOT kill anaerobes"
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What is mechanism of action of aminoglycosides?
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Bind to 30 s subunits and interfere with protein synthesis
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What is unique to aminoglycosides?
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They require oxygen for uptake, so Can NOT be used for anerobic infection. They are synergistic with Beta-lactams and Aztreonam.
2) Also has a post-antibiotic effect: antibacterial killing can continue after serum drug concentration declines below minimum inhibitory concentration. |
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what is neomycin used for?
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Bowel surgery
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What agents are used for plague and tularemia?
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Streptomycin
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What is the aminoglycoside toxicity?
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Nephrotoxicity with Cephalosporins
Ototoxicity with loop diuretics Teratogen. |
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What are the tetracycline classes?
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Tetracycline, doxycycline, demeclocycline, and minocycline.
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What is action of tetracyclines?
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It binds to 30S and prevents protein synthesis. Has limited CNS penetration.
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Which tetracycline can be used in renal failure?
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Doxycycline because it is excreted in feces.
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What are some contraindications with taking doxycyline?
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Can NOT take with milk, antacids, or iron-containing preparations because divalent cations inhibits its absorption in the gut.
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What are the clinical uses of tetracyclines?
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VACUUM THe BedRooom
1) Vibrio 2) Acne 3) Chlamydia 4) Ureplasma Urealyticum 5) Mycoplasma pneumoniae 6) Tularemia/H.pylori 7) Borrelia 8) Ricketssia |
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What is the toxicity of tetracyclines?
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Gi distress, discoloration of teeth, growth inhibition in children, and photosensitivity. ABOSLUTELY CONTRAINDICATED IN PREGNANCY.
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What is special about the tetracycline demeclocycline?
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It is an ADH antagonist, so can act as a diuretic in SIADH.
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