Term
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Definition
used to fight infectious diseases
UP to 30% of all hospitalized patients receive microbials
Modern antimicrobials 30's and 40's
Sig. reduced morbidity and mortality from infections |
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Term
| Basic Principals of Antimicrobials |
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Definition
Chemotherapy (use against invading organisms)
Antibiotic (chemical that is produced by one microbe and has the ability to harm other microbes)
Antimicrobial agent (has the ability to kill or suppress microorganisms) |
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Term
| Selective Toxicity (Why don't antibiotics kill us?) |
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Definition
Toxic to microbes harmless to host due to:
Disruption of cell wall: rigid cell wall/high bacterial intracellular osmotic pressure
Inhibition of an enzyme unique to bacteria: sulfonamide inhibition of bacterial folic acid synthesis (key for UIT's)
Disruption of bacterial protein synthesis: Ribosomal differences btw human and bacterial cells |
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Term
| Classifications of Antimicrobial Drugs |
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Definition
Drugs work on:
Cell wall synthesis
Cell membrane permeability
Protein sythnesis (lethal)
Non lethal inhibitors of protein synthesis
Synthesis of nucleic acids
Antimetabolites
Viral enzyme inhibitors
Lehne classifications:
By susceptible organism
MOA (mechanism of action) |
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Term
| 4 basic actions of antibiotic drug resistance |
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Definition
decrease the concentration of the drug at its site of action
inactivate a drug
alter the structure of a drug target molecule
produce a drug antagonist |
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Term
| Organisms w/microbial drug resistance |
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Definition
MRSA (methicillin resistant s. Aureus)
VRE (Vancomycin resistant Enterococcus)
MDRTB (Multi drug resistant TB) |
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Term
| Mechanisms for acquired resistance |
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Definition
Spontaneous mutation
-Random changes in microbes DNA
-single drug resistance
Conjucation
-extra chromosomal DNA is transferred from one bacterium to another
-most common gram neg. bacteria
-Multiple drug resistance |
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Term
| Things that delay or stop emergence of drug resistance |
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Definition
vaccinate
get catheters out
target the pathogen
access the experts
practice antimicrobial control
use local data |
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Term
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Definition
identify organism to treat
drug sensitivity of organism
host factors
durg may be rules out due to:
allergy
inability to penetrate the site of infection
patient variables |
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Term
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Definition
| Antibiotic therapy before causative organism is identified, |
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Term
Delaying Emergence of drug resistance
what can we do? |
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Definition
Treat infection not contamination
treat infection not colonization
know when to say NO to VANCO
Stop treatment when infection is cured or unlikely
isolate the pathogen
Break chain of contagion |
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Term
| Identifying the Infection organism |
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Definition
Match DRUG w/BUG
Gram stained preparation
Determining drug susceptibility
Disk Diffusion test
Broth dilution procedure (more precise)
which can determin: minimum inhibitory concentration and minimum bacterialcidal concentration |
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Term
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Definition
Host defenses
site of infection
age
pregancy and lactation
previous allergic reactions
genetic factors |
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Term
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Definition
antibiotic must be present at the site of infection and for a sufficient amt of time
antibiotics must not be discontinued prematurely
teach patients to complete full prescription |
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Term
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Definition
Antimicriobial effectss of antibiotic combinations: additivae, potentiative (synergistic) antagonist
Indications: Mixed infections, preention of resistance, decreased toxicity and enhanced baterial action
Discadvantages of combinations |
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Term
| Prophylactic use of antimicrobials |
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Definition
Agents given to prevent infection rather than treat an established infection
Surgery
Bacterial endocarditis
Neutropenia
Other indications |
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Term
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Definition
Attempted treatment of untreatable infections
treatment of fever or unknown origin
improper doses
treatment in the absence of adequate bacteriologic information
Omission of surgical drainage (must drain for antibiotic to work) |
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Term
| monitoring Antimicrobial Therapy |
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Definition
Monitor clinical responses and lab results
Frequency of monitoring should increase w/severity of infection
Clinical indicators of success:
Reduction of fever, resolution of signs/symptoms related to the affected organ
Serum drug levels for toxicity |
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Term
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Definition
Active against a variety of bacteria
Direct Toxicity- low
Principal adverse effect: allergic reaction
Beta Lactam Ring in their structure***
Beta Lactam family includes: Cephalosporins, aztreonam, imipenem, neropenem, and ertapenem |
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Term
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Definition
Weaken cell wall causing bacteria to take up excessive water and rupture
Active against bacteria that are undergoing growth and division
Generally BACTERICIDAL
Bacterial resistance can happen |
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Term
| 3 factors in bacterial resistance |
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Definition
Inability of penicillins to reach the target
inactivation of penicillins by bacterial enzymes
production of penicillin binding proteins (PBP's) that have a low affinity for penicillins (MRSA) |
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Term
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Definition
Gream negative cell wall or envelope
3 layers, thin cell wall and an additional outer membrane that is hard to penetrate
Gram positive cell wall/envelope
2 layers
relatively thick cell wall that is easily penetrated |
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Term
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Definition
Beta Lactamases
Enzymes that render penicillin inactive
Bacteria can produce a large variety of these enzymes specific for penicillins (and other beta lactam antibiotics) |
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Term
| Classifications of Penicillins |
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Definition
Narrow spectrum penicillins (pencillinase sensitive)
Narrow spectrum penicillin
(Pencillinase resistant)
Broad spectrum penicillins
Extended spectrum penicillins |
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Term
| Penicillin G (Benzylpenicillin) |
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Definition
Bactericidal to a number of gram positive and some gram negative organism
IM and SC only
Adverse effects
-least toxic of all antibiotics
-Penicillins are the most common cause of drug allergy 0.4-7% of patients |
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Term
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Definition
Assesses for penicillin allergy in each patient who will be receiving penicillin
-if history of mild reaction- consider cephalosporin
--if history of anaphylaxis- avoid administration of penicillin or cephalosporins |
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Term
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Definition
Immediate (reaction 2-30 min)
Accelerated (reaction in 1-72 hrs)
Late (reaction takes days or weeks) |
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Term
| Penicillin Allergy Anaphylaxis |
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Definition
Laryngeal edema
Bronchoconstriction
Severe Hypotension |
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Term
| Treatments for allergy of Penicillin |
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Definition
| Epinephrine, Respiratory support, prevention (skin testing) |
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Term
| Drug interactinos w/Penicillin |
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Definition
Aminoglycosides
-PCN weakens cell wall and promotes action of aminoglycosides. In high concentrations may inactivate aminoglycosides. NEVER administer together in same IV solution |
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Term
| Penicillinase Resistant Penicillins |
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Definition
Nafcillin, oxacillin, dicloxacillin,narrow spectrum used afainst penicillinase producing staph
MRSA-- resistant to all pinicillinase resistant PCN's) |
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Term
| Broad Spectrum Penicillins |
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Definition
Broad: Aminopenicillins (Ampicillin (principen) Amoxicillin (amoxil, dispermox, moxatag, trimox) VERY common drugs
Adverse effects:
Rash
Diarrhea
(I get a rash w/amoxacillin) |
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Term
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Definition
Beta Lactamase inhibitors: Clavulanic acid, tazobactam, subactam
Extends antimicrobial spectrum when combined w/ penicillinase sensitive antibiotics
-Ampicillin/sulbactam (Unasyn)
-Amoxicillin/clavulanic acid (Augmentin)
Ticarcillin/clavulanic acid (Timentin)
Piperacillin/tazobactam (zosyn) |
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Term
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Definition
are the most widely used antibiotic.
-beta lactam antibiotic
-bactericidal (kills)
-usually given parentally
-toxicity is low |
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Term
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Definition
Bind to penicillin binding proteins (PBP's) disrupt cell wall synthesis and cause cell lysis
most effective against cells undergoing active growth and division |
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Term
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Definition
Beta lactamases (cephalosporinases)
3rd and 4th generation agents more resistant than 1st and 2nd generation agents |
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Term
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Definition
over 20 cephs currently in use,
1st and 2nd generations are rarely used for active infections, 3rd are preferred therapy for several infections, highly active against gram NEGATIVE organisms, able to penetrate CSF,
4th generations- yet to be established |
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Term
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Definition
1st- Cefazolin (ancef)
2nd- Cefactor (Ceclor)
3rd- Cefoperazone (Cefobid)
4th Cefepime (maxipime)
Over time: increasing activity against gram negative bacteria and anaerobes, resistance to destruction by beta lactamases and ability to reach CSF |
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Term
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Definition
Probenecid (gout meds they will prolong effect)
Alcohol (vomiting)
Drugs that promote bleeding
Calcium and cettriaxone (forms chunky substances that can be fatal)
Adverse effects:
Allergy, Bleeding, Thomboplebitis |
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Term
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Definition
Beta lactam antibiotics have an EXTREMELY BROAD antimicrobial spectrum w/low toxicity
used widely for mixed infections
NOT active against MRSA
-Imipenem (primaxin)
Meropenem (merrem IV)
Ertapenem (Invanz)
Doripenem (Doribax) |
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Term
| Vancomycin (Vancocin, Vacoled) |
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Definition
MOA: inhibits cell wall synthesis
Uses: Severe infections ONLY
Methiciliin restistant staph aureus or staph epidermidis
Oral dose for Clostridium difficile if metronidazole was tried and ineffective
Drug of last resort |
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Term
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Definition
Ototoxicity (reversible or not)
Red man syndrome
Thrombophlebitis (common)
Thrombocytopenia (rare)
Allergy |
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Term
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Definition
4 members of the tetracycline family available ofr systemic therapy
ALL broad spectrum
-Tetracycline
-Demeclocycline
-Doxycycline
-Minocycline |
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Term
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Definition
Broad spectrum antibioticcs
Inhibit Protein synthesis
Increase bacterial resistance has emerged |
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Term
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Definition
Topically for acne
Rickettsial disease
chlamydia trachomatis
Brucellosis
cholera
Mycolplasma pneumoniae
lyme disease
Helicobacter pylori
Anthrax
Peptic ulcer Disease
Periodontal disease |
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Term
| Tetrycycline absorption/chelation and adverse effects |
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Definition
Absorbtion: forms insoluable chelates w/ calcium, milk products, iron supplements, mangesium containing laxatives, and most antacids
ADVERSE effects
Gastrointestinal irritation
Effect on BONE and teeth
superinfection
hepatotoxicity
Renal Toxicity
Photosensitivity (SPF) |
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Term
| Drug and food interaction w/Tetrycyclines |
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Definition
absorption of tetra decreased when given with:
milk
calcium supplements
iron supplements
magnesium containing laxatives
most antacids
any metal |
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Term
| Macrolides (Erythromycin) |
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Definition
Broad spectrum
MOA: inhibition of protein synthesis
Usually bacteriostatic but can be bacterialcidal
Use if ALLERGIC to PENECILLIN
active against most gr. postive and some gram negative |
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Term
| Therapeutic uses: Macrolides |
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Definition
| Whooping cough, acute diphtheria, corynebacterium diptheriae, chlamiydial infections, M. pneumoniae, group A streps pyogenes |
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Term
| Adverse effects of Macrolides |
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Definition
Gastrointestianal
QT prolongation and sudden cardiac death
superinfection |
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Term
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Definition
Clarithromycin (Biaxin)
Azithromycin (Zithromax)
Dirithromycin (Dynabac)
Troleandomycin (Tao)
They all like the lungs |
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Term
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Definition
Inhibits protein synthesis
can induce severe antibiotic associated pseudomenbranous colitis(fatal)
Active against Gr - and gr +
Indicated ony for certain anaerobic infections located outside the CNS |
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Term
| Clindamycin (Cleocin)Adverse effects |
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Definition
Adverse: Antibiotic associated pseudomembranous colitis
Hepatic toxicity
Blood dyscrasias
(Changes in blood coagulation)
Diarrhea
Hypersensitivity reactions |
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Term
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Definition
First member of NEW class of antibiotics
OXAZOLIDINONES
used against multi drug resistant grm + pathoens (eg. vacomycin resistant enterococci (VRE) and MRSA |
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Term
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Definition
Bacteriostatic inhibitor of protein synthesis
cross resistance w/other agents unlikely
active against aerobic and facultative gr + bacteria
VRE and MRSA |
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Term
| Linezolid (Zyvox) Side effects and interactions |
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Definition
Side effects:
Diarrhea
Headache
Nausea and vomiting
May cause myelosuppression
drug interactions w/ MAOI's and SSRI's |
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Term
| Dalfopristin/Quinupristin |
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Definition
First members of Sterptogramins (new class of antibiotics)
Inhibit bacterial protein synthesis
Principal indication: VRE
ADverse Effects: hepatotoxicity
Drug ineractions: CYP3A4 |
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Term
| Chloramphenicol (Chloromycetin) |
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Definition
Broad spectrum antibiotic
Inhibits protein synthesis
used: for life threatening infections for which safer drugs are ineffective or contraindicated
ADVERSE effects: reversible bone marrow depression
fatal aplastic anemia
gray syndrom
GI effects
Peripheral neropathy |
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