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102 Cards in this Set
- Front
- Back
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Which narrow spectrum drugs work against gram positive organisms?
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Penicillin G and V
Penicillinase Vancomycin Erythromycin Clindamycin |
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Which narrow spectrum drugs work against gram negatives?
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Aminoglycosides
Cephalosporins |
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Which drugs work against mycobaterium tuberculosis?
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Isoniazid
Rifampin Ethambutol Pyrazinamide |
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What are the broad spectum drugs that work against gram positive and gram negative organisms?
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Broad spectrum penicillins like ampicillin
Extended spectrum penicillins cephalosporins (3rd gen) Tetracyclines imipenem, peropenem Trimethoprim Sulfonamides Floroquinolones |
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What is the difference between bacteriostatic rx and bactericidal ones?
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Bacteriostatic rx inhibit growth of bacteria where bactericidal ones kill bacteria, more effective
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There are 5 ways that antibiotics work, what are they?
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1. Inhibition of bacterial cell wall synthesis
2. Altration in cell membrane function 3. Inhibition of protein synthesis 4. Interference of ncucleic acid metabolism 5. Interference with intermdediate cell metabolism |
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What factors should be considered when selecting an antibiotic?
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signs/symptoms
Suspected site of infection Suspected causative organims antibiotic suscetibilities prior antibiotic usage pt allergies cost pt age renal/hepatic insufficiency pregnancy/lactation |
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What classes of antibiotics have a beta-lactam ring in their structure? What is their MOA? Bactericidal or bacteristatic?
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Penicillins
cephalosporins aztreonam imipenem Carbapenem MOA: Disruption of bacterial cell wall, therefore they are bactericidal. |
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Penicillins
Spectrum: |
MOA: Inhibits cell wall synthesis and activates autolysins which punch holes in cell wall.
Spectrum: gram +/-, anaerobes |
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MOR of penecillins:
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MOR: Bacterial production of an enzyme that cleaves the beta-lactam ring and inactivates the drug.
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How are penicillins given?
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IV
PO IM |
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Do penicillins penetrate the CSF?
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YES
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How are Penicillins exreted?
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They are metabolized hepatically and excreted renally.
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What a/e are experienced with penicillins?
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hypersensitivity rxns: rash, angeioedema, interstitial nephritis, anaphylaxis
GI: n/v/d phebitis seizures Hematologic: hemolysis, neutropenia, thrombocytopenia superinfection with candida |
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Rx interactions with penicillins?
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Bacteriostatic antibiotics (tetracycline)
Uricosuric agents like benemid and indocin aminoglycosides, penicillins will inactivate them OCs, less effective |
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What are beta-lactamase inhibitors?
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These are drugs added to penicillins that save the drug from being eaten by the bacteria itself, like a booster.
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Examples of betalactamase containing agents?
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Augmentin
Unasyn Timentin Zosyn |
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What about cephalosprorins?
Class? MOA? MOR? |
Class? beta lactam
MOA? same as penicillin, inhibit cell wall synthesis and autolysin action MOR? Prevents rx from reaching its site of action |
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What is the significance of the generations of cephalosporins?
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There are 4 generations and as we move through there is an increasing activity toward anaerobes and gram neg orgs.
Increased resistance to destruction of betalactimase Increased ability to penetrate CSF Increased permeability of BBB. |
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So first generation ones (cefalzolin, cephalexin and cefadroxil area active against what?
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Gram + orgs. except MRSA
Activity against simple grm neg orgs )E. coli, K. pneumoniae |
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Are second generation cephalosporins as good against gram positives as first genreation?
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No, less so, but better coverage of many grm neg and anaerobes.
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Which generation is active against pseudomonas?
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Third, can penetrate CSF readily.
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Fourth generation cephalosporins are what? (CSF? spectrum?)
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Able to cross CSF
Very Broad spectrum |
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Absorption of cephalosporins?
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Must begive IM or IV due to poor PO absorption
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Excretion/metabolism?
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Renally excreted, hepatically metabolized.
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Adverse effects of cephalosporins?
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Like penicillins, hypersensitivty
Px at injection site, phebitis Hematologic: neutropenia, thrombocytopenia Elevated PT GI: n/v/d |
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What are carbapenems? examples?
MOA? |
A class of betalactam antibiotics.
Ex: Ertapenem, Imipenem "gorillacillin" - very broad spectrum. MOA? Same as others |
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Resistance and carbapenems?
So, used for? |
Resistant to most betalactamases.
Used for infections resistant to other drugs |
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Active against?
not active against? |
Gram positive
gram begatuve anaerobes Not active against MRSA, MRSE |
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A/e?
Rx interactions? |
Hypersensitivity and cross reactivity with other betalactams
n/v/d Seizures Rx interactions: probenecid |
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What about azactam? What is it and what is it active against?
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It is a betalactam. It is activea gainst wide spectrum of gram negative bacteria. No Gm positive or anaerobic coverage. crosses CSF
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A/e?
Rx interactions? |
Same as other betalactams, elavation of liver enzymes
No rx interactions |
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_______________ are narrow spectrum antibiotics used against gram-neg bacilli.
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Aminoglycosides.
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Aminoglycosides work by...
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Disrupting protein synthesis (ribosomal activity) resulting in cell death, bactericidal.
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They can cause serious injury to....
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Kidney and inner ear
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Aminoglycosides are (well/poorly) absorbed via the GI tract. Distribution? Excretion?
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Poorly, therefore must be given IM or IV. Distributed poorly, does not penetrate broncial secretions or CSSF. Renally excreted.
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Aminoglycosides are effective against...
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Gram negative microbes only. Synergy wtih beta-lactams.
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What is important about serum levels with aminoglycosides?
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Peak-traugh levels differ so blood levels should be drawn one hour after the start of an IV or IM and trough levels should be drawn prior to infusion. Random draws 6-14 hours after first dose.
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What a/e are associated with aminoglycosides?
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Nephrotoxicity, ototoxicity, neuromuscular blockade --> acute musculare paralysis.
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Vancomycin is used in treatment of serious infections like_____________ and _________.
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C. difficille and MRSA
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Vanco works by...and is considered (bactericidal/bacteristatic).
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Inhibiting cell wall synthesis, bactericidal.
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Resistance and vanco?
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RARE!
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The microbiological spectrum of vanco includes...
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Gram positive organisms (including MRSA) AND C. dif.
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Absorption of vanco...
Distribution? |
Poor absorption, must be given IV for systemic treatment (orally available for GI infections).
Well distributed. |
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Elimination of vanco?
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Orally eliminated via GI, IV gorm is renally eliminated (decrease dose if pt is renally insufficient).
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A/e of vanco...
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Red man syndrome - associated with rapid infusion, assco with histamine release. Otto and ne[hrotoxicity
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Macrolides
MOA: |
Bacteriostatic, slows groth of cells and body clears the organism. Binds to bacterial ribosomes and inhibits protein synthesis.
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Microbiological spectrum of macrolides?
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Some gram pos and some gram negative
ex: Clamydia, legionnaire's disease, walking pneumonia. NO GI BUGS! |
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Absorption?
Distribution? Elimination? |
Adequate
Benetrates most fluids but CSF Liver adn biliary |
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a/e?
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GI distress n/v/d
ototoxicity phlebitis cholestatic hepatitis - hypersensitivity reaction QT prolongation |
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Rx interactions?
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Theophylline (may increase serum lvls)
Cyclosporine Warfarin (prolonged bleeding time) Antiarrhythmatics |
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Tetracyclines
MOA: |
Same as macrolides, bacteriostatic, bind to ribosomes nad inhibit protein synthesis.
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MOR of tetracyclines:
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Interference of drug transport into bacyterial cell, alteratino of binding site to ribosome
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Microbiological spectrum of tetracyclines?
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Some gram positive and gram negative coverage...lots of resistance
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Absorption?
Distribution? Elimination? |
Adequatelu absorbed but incomplete, impaired by dairy products and food with Ca
Penetrates into all fluids, including CSF Renally eliminated. |
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A/e?
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GI
Photosensitivity Hepatotpxicity Effects calcified tissue so do not give to pregnant womena nd young children Development of superinfection with candida Nephrotoxic |
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Rx interactions?
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antacids
OCs - decreases efficacy |
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Glycycline - Tygacil (only one in class)
MOA: |
This is like a super tetracycline, good for bugs resistant to tetras:
Bacteriostatic Binds to ribosomes and inhibits protein synthesis Not affected by resistance mechanisms like beta-lactamases |
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Spectrum?
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Many gram + and gram - organisms including MRSA and VRE and anaerobes.
Used against multiagent resistant organisms |
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Administered?
Distributed? Elimination? |
IV
Widely distrubted Biliary excretion |
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A/e?
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GI: n/v/d
Photosensitivity Effects on calcified tissues Development of superinfection with candida Anti-anabolic action: increased BUN, azotemia, acidosis |
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Rx interactions?
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OCs
Increased levels of oral anticoagulants |
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Ketolides: Telithromycin (Ketek)
MOA? |
MOA: Similar to macrolides, binds to bacterial ribosomes nad inhibit protein synthesis.
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Spectrum
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Treatment of bugs resistant to macrolides
MRSA, Legionaires, walking pneumonia, etc. |
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Absorption?
Distribution? Elimination? |
Adequate
Penetrates well EXCEPT CSF Hepatic metabolism and renal excretion |
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A/e:
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GI
Acute liver failure visual disturbances exacerbates myesthenia gravis |
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Rx interactions?
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Same as macrolides:
theophylines cyuclosporine warfarin antiarrhythmatics |
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Clindamycin
MOA: |
Bacteriostatic: disables organism
Binds to bacterial ribosomes and inhibits pritein synthesis |
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Spectrum?
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Gram + and Gram - anaerobes
Gram + aerobes |
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Absorption?
Distriubtion? Elimination? |
well absorbed via GI
Widely distributed except into CSF Hepatically metabolized |
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A/e?
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D/n/v
Antibiotic associated colitis: superinfectino with C diff: treat that with vanco Rash |
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Flagyl: antibacterial antiparasitic
MOA: |
bactericidal
Selecteively produces cytotoxic effects in anaerobes |
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Flagyl (metronidazole) spectrum?
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Gram+ and gram- anaerobes
Active against vaginitis, giardia, some amoeba |
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Adsorption?
DistributioN? Excretion? |
Well absorbed
Well distributed including CSF and breast milk Hepatic metabolism |
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a/e?
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n/v/d
neurotoxicity dark/reddish urine mutgenic potential so avoid in pregnancy |
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Rx interactions?
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Anticoagulants
Alcohol |
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Co-trimoxazole/trimethoprim (Bactrim, Septra)
MOA: |
Inhibition of folic acid synthesis --> inhibition of DNA, RNA, and protein synthesis, bactericidal
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MOR to bactrim, septra
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Chromosomal and plasmid mediated
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Spectrum DOESN"T cover?
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pseudomonas aeruginosa
enterococcus group A beta hemolytic streptococci anaerobes |
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Absorption?
Distribution? Excretion? |
Well absorbed after oral administration
Well distributed including CSF Hepatic metabolism and renal excretion |
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A/E?
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hypersensitivity rxns (steven-johnsons syndrome)
GI: N/v Hematologic toxicity nephrotoxicity |
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Rx interactions:
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warfarin
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Quinolones/Fluoroquinolines
MOA? |
bactericidal
inhibits bacterial DNA gyrase an enzyme essential for DNA synthesis |
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Spectrum?
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Gram +, gram -, anaerobes
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Absorption?
Distribution? Excretion? |
excellent: iv/PO
widely distributed Renal elimination |
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A/E?
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GI: n/v
CNS (light headedness, dizziness, headache) Skin rash Premature closure of epiphyseal growth plate, don't use in pregnancy |
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Rx interactions?
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These bind to metals so space with administration Ca, Fe
Theophylline Antacids Warfarin Antiarrhythmatics |
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Oxazolidinones - Linezolid (Zyvox)
MOA: |
Bacteriostatic
Inhibits protein synthesis at the bacterial ribosome |
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Spectrum:
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Gram positive, some atypicals
MRSA, GESA, VRE |
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Absorption
Distribution Elimination |
excellent
well distributed metabolized in liver and excreted in kidneys |
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indications for use:
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Vanco resistant enterococcal infections
MRSA infectios that don't respond to vanco |
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a/e:
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d/n/v
thrombocytopenia increased hepatic enzymes leukopenia Peripheral neuropathy |
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Streptogramins - quinupristin/dalfopristin (synercid)
MOA: |
Used for seriously resistant bugs
Bacteriostatic, acts at bacterial ribosome to inhibit protein synthesis |
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spectrum:
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Only Gram +, MRSA, VRE,
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Absorption:
Distribution: elimination: |
must be given IV
well distributed metabolized to active metabolites fecal excretion |
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a/e
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inflammation at infusion site, thrombophlebitis
n/v/d rash, puritis arthralgia, myalgia hyperbilirubinemia |
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rx interactions:
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P450 drugs
cyclosporine midazolam, diazepam cisapride |
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lipopeptides - daptomycin (Cubicin)
MOA: |
Binds to bacterial membrane and causes rapid deplarizatin of membrane potential which results in inhibitionofbacterial protein, DNA and RNA synthesis and cell death (punches holes in cell membrane)
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Spectrum?
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Gram + only
MRSA GISA VRE Treatment of bacteremia and endocarditis |
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absorption
distribution elimination |
administered IV
92% protein bound renally excreted |
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a/e:
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Muscle weakness and pain
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Rx interactions:
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statins
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