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What types of Micro-organisms cause infections?
- Parasitic worms
What are the bodies natural barriers to infection?
- Host Defenses:
- Mucous Membranes
- Gastric Acid
- Immune Factors
What are some factors that put people at a greater risk for infection?
- Advanced age
- Diseases that suppress the immune system
- Impaired blood supply
Explain in general how Antibacterials & Antimicrobials work.
They are substances that inhibit bacterial growth or kill bacteria & other microorganisms.
What is the technical definition of "Antibiotic"?
refers to chemicals produced by one kind of microorganism that inhibits the growth of or kills another.
How do Bacteriostatic drugs work?
By inhibiting the growth of bacteria.
How do Bactericidal drugs work?
Kills the bacteria
What are the 5 mechanisms of Antibacterial action that are responsible for the inhibition of growth or destruction of microorganisms?
- Inhibit cell wall synthesis
- Alter membrane permeability
- Inhibit protein synthesis
- Inhibit synthesis of RNA & DNA
- Interferes w/metabolism
Antibacterial drugs must do two things in order to completely inhibit bacterial growth or kill bacteria, what are those two things?
- Penetrate cell wall in sufficient concentration.
- Must have an affinity to the binding sites on the bacterial cell.
How does the MEC (minimum effective concentration) of the Antibacterial effect the inhibition/killing of the bacteria?
If the MEC is not maintained t/o the Antibacterial cycle it can leave room for another infection to get in or not completely kill the one it was meant to tx.
The duration of time of an Antibacterial agent depends on what factors?
- Type of pathogen
- Site of infection
- Immunocompetence of the host
The effect that Antibacterial drugs have on an infection depends not only on the drug but also on the host's defense mechanisms. What are these factors?
- Organ fxn
When a bacteria are sensitive to a drug what happens to the pathogen?
It is inhibited or destroyed.
When a bacteria are resistant to an Antibacterial what happens to the pathogen?
It continues to grow, despite administration of that Antibacterial drug.
How does bacterial resistance occur?
- Inherent resistance: bacteria is naturally resistant to the Antibacterial.
- Acquired resistance: prior exposure to antibacterial.
- Inappropriate use of Antibiotics
- Nosocomial infxns
- Cross-resistance: when a certain bacteria are resistant to certain Abx, but bacteria changes & is now resistant to many drugs.
Typically one Antibiotic will successfully Tx a bacterial infection, but what is the next step if that doesn't work?
How do we know which Antibiotic will work best?
By doing a Culture & Sensitivity lab
What are the 3 major A/R associated w/the administration of Antibacterial drugs?
- Allergic Rxns (hypersensitivity)
- Organ Toxicity
What are narrow-spectrum Abx primarily effective against?
one type of organism (b/c they're selective, they are more active against those single organisms than the broad-spectrum)
What are broad-spectrum Abx effective against?
both gram-positive & gram-negative oraganisms.
How often do bacteria reproduce?
about every 20 minutes by cell division
When classifying bacteria by staining properties, gram staining is determined by the ability of the bacterial cell wall to retain a purple stain by basic dye. If the purple is retained what type of microorganisms are they?
What are the s/s of an infection?
- Pain & swelling
- Weight loss (systemic infection)
- purulent drainage
What nursing assessments should be done before administration of an Abx?
- Location of infection
- Other current meds
- if IV Abx: compatibility w/other meds being hung
What nursing assessments need to be done during Abx therapy?
What nursing assessment needs to be done after Abx therapy?
- s/s resolved?
- late s/e
What is Empiric Therapy?
- The initiation of Abx Tx before determination of a firm diagnosis. Abx selected is one that can best kill the microorganism known to be the most common cause of that infection.
- (ie. UTI (ecoli) still do C&S but start on Abx early b/c probable common cause for UTI)
What is prophylactic therapy?
Giving an Abx to prevent an infection or possibility of infection.
How do we determine a therapeutic response?
Decrease in specific s/s of infection.
How do we determine a sub-therapeutic response?
When s/s of infection do NOT improve.
Why does a sub-therapeutic response occur?
- -Pt. not taking the Abx right
- -Not enough was given to get pt. to the MEC (Wrong dose)
- -Bacterial resistance
- -Course of therapy not long enough (dr. Rx short or pt. didn't take full course)
What are the general a/r to Antibacterials?
Mild rxn: Rash, pruritus, hives
What are the severe a/r to Antibacterials?
Anaphylactic shock: bronchospasms, laryngeal edema, vascular collapse, cardiac arrest.
What are the treatments for Anaphylactic shock?
Epinephrine, Antihistamine, bronchodilator
What is a Superinfection?
a secondary infection that occurs when the normal microbial flora of the body are disturbed during Abx therapy.
Where can Superinfection's occur?
- Respiratory Tract
- GU tract (vagina; yeast infxn)
A superinfection typically occurs after how long on an Abx?
over 1 week
Another A/R that can occur from Abx Tx affects the liver and kidneys, what is it?
How do we test for organ damage?
- Labs: BUN, Creatinine (kidneys)
- Liver: AST, Bilirubin
What are the classifications of Abx therapy?
Penicillins were first introduced to kill what type of bacteria?
How do basic Penicillins work against bacteria?
- They inhibit bacterial cell wall synthesis.
- They are a Narrow-spectrum drug.
Broad-spectrum Penicillins affect the bacteria how?
- They are Bactericidal
- (Amoxicillin, Ampicillin)
When Broad-spectrum Abx (amoxicillin) is combined w/a beta-lactamase inhibitor (enzyme inhibitor) (ig. Clavulanic acid), the resulting Abx does what?
Inhibits the bacterial beta-lactamases, making the Abx effective & extending its antimicrobial effect.
Name the 3 Beta-lactamase Inhibitors.
- Clavulanic Acid (Amoxicillin+Clav.Acid=Augmentin)
- Sulbactam (Ampicillin+Sulb. =Unasyn)
- Tazobactam (Piperacillin+Tazo.=Zosyn)
What is the purpose of combining Beta-lactamase Inhibitors with Broad-spectrum Abx?
To potentiate the effectiveness of Penicillins
What are the s/e of Penicillins?
- Common:N/V, Diarrhea
- *Hypersensitivity: Rash -->Could become-->Anaphylaxis
What are the drug interactions for Penicillins?
- Oral Contraceptives: Broad-sprectrum Pencillins <the effectiveness of oral BCP, need to use alternate BC until end of cycle.
What are the nursing interventions with Penicillins?
- check ALLERGIES before drugs given
- Monitor closely during 1st dose
- Take w/meals
- Assess for s/e
- Use alternate form of BC if taking BCP
Where was cephalosporium acremonium discovered?
in seawater at a sewer outlet off the coast of Sardinia.
Cephalosporium Acremonium was a fungus found to be effective against which bacterias?
- Gram-positive & Gram-negative
- & resistant to beta-lactamase
How do Cephalosporins work?
They are bactericidal. They act by inhibiting the bacterial enzyme necessary for cell wall synthesis. Lysis to the other cells occurs, & the bacterial cell dies.
What are Cephalosporins used to Tx?
- Respiratory infections
- Skin infections
- Bone infections
- Joint infections
- Genital infections
For Cephalosporins to be effective against numerous organisms what had to be done to their molecules?
Had to be chemically altered.
Four groups of Cephalosporins have been developed, identified as generations. What are these generations?
First, second, third, fourth generation
What is the difference between the generations of Cephalosporins?
Each generation is effective against a broader spectrum of bacteria.
Name the 1st Generation of Cephalosporins.
Name the 2nd Generation of Cephalosporins.
Name the 3rd Generation of Cephalosporins.
Name the 4th Generation of Cephalosporins.
Most of the 3rd & 4th Generation of Cephalosporins are effective in treating what?
Sepsis & many strains of gram-negative bacilli.
If a patient is allergic to Penicillin but are taking a Cephalosporin, what should the nurse watch for?
An allergic rxn to the Cepholasporin
What are the s/e of Cephalosporins?
- N/V, diarrhea, ^bleeding w/large doses
- *A/R= Nephrotoxicity
What should the nurse assess for before giving a Cephalosporin?
- C&S before therapy
- Take w/food or 1he before or 2hr after
- Assess renal & liver fxn (if exisiting impairment)
- Admin IV: over 30-45min
- Monitor for superinfection: if on abx of 1wk
The Antimicrobial groups Macrolides & Tetracyclines act on bacteria in what way?
- Bacteriostatic: inhibit bacterial growth
- *may be bactericidal depending on drug dose or pathogen.
The Antimicrobial groups Aminoglycosides & Fluoroquinolones act on bacteria in what way?
Name some of the Antimicrobials in the Macrolide group.
- Erythromycin (E-mycin)
- Azithromycin (Zithromax/Z-pack)
- Clarithromycin (Biaxin)
Which Antimicrobials in the Microlides group are broad-spectrum antibiotics?
- Azithromycin (Zpack)
- Clarithromycin (Biaxin)
- Erythromycin (E-mycin)
What are the Antimicrobials group, Macrolides used to treat?
- Mild-moderate infections of the:
- respiratory tract
- GI tract
- skin & soft tissue
- impetigo contagiosa
Erythomycin (E-mycin) is the drug of choice to treat what two issues?
- Mycoplasmal Pneumonia
- Legionnaire's Disease
What s/e or a/r could occur when taking the Macrolides; Erythromycin, Clarithromycin, & Azithromycin?
- GI distress- N/V, Diarrhea, abdominal cramping
- Hepatotoxicity (when taken in high doses w/other hepatotoxic drugs. In pts w/pre-exisiting liver dx or on other liver impairing drugs.)
Nurses need to be aware of what drug interactions with the Macrolides; Erythromycin, Clarithromycin, & Azithromycin?
- They ^ serum levels of Warfarin
- Theophylline (Bronchodilator)
- Carbamazepine (anticonvulsant)
The Macrolide Erythromycin should NOT be given with what other drugs?
What other drugs will increase the Macrolide Erythromycin when taken with them?
- Fluconazole (Diflucan)
- Ketoconazole (Nizoral)
- Diltiazem (Cardizem)
- **risk of sudden cardiac death**
The Macrolide Azithromycin levels may be reduced by what other drug?
What should a nurse include in nursing interventions for Erythromycin, Clarithromycin, & Azithromycin?
- C&S before therapy
- Monitor liver enzymes during therapy
- Advise clients to complete Abx course
- & report any s/e or a/r
- Administer antacids 2hrs before or 2hrs after meals
- Give Zpack 1hr before or 2hrs after meals w/full glass of water
What is the action of the Macrolide Clindamycin?
- Inhibit bacterial protein synthesis
- *Depending on dosage could be: Bacteriostatic & Bactericidal
Inhibits bacteria growth
What are the s/e or a/r of the Macrolide Clindamycin?
- GI distress
- Anaphylactic Shock
What are the drug interaction problems with the Macrolide Clindamycin?
- Phenytoin (Dilantin)
What is the action of the Macrolide Vancomycin?
- Bacteriostatic: Inhibits cell wall synthesis
What are the indications for use of the Macrolide Antibiotic, Vancomycin?
- Serious infections of:
- LRI (Lower respiratory infection)
What are the contraindications of the Macrolide Abx, Vancomycin?
Use cautiously w/kidney dysfunction or hearing loss.
What are the s/e or a/r of the Macrolide Abx, Vancomycin?
- Ototoxicity & Nephrotoxicity
- Pseudomembranous Colitis
- Red Neck syndrome
What are the nursing interventions for the Macrolide Abx, Vancomycin?
- C&S prior to therapy
- Monitor Vanco levels
- Monitor BP, renal fxn, superinfection, hearing, IV site
- Infuse over 60min or greater
- ^fluids to <nephrotoxicity
What is the action of Aminoglycoside Antibiotics?
Inhibit bacterial protein synthesis (Bactericidal)
Name some Aminoglycoside Antibiotics.
What are the possible routes for Aminoglycoside Abx?
- IM, IV
- *Neomycin; PO or IM
What types of infections are the Aminoglycoside Abx used for?
Gram-negative bacteria (ie. E. coli)
The Aminoglycoside Abx, Neomycin is used pre-op what?
What are the s/e or a/r of the Aminoglycoside Abxs?
- GI disturbances, HA, parethesias, skin rash, fever
- nephrotoxicity (Amikacin & Gentamicin)
The Aminoglycosides increase the effects of what medication, thereby causing what problem?
What are the drug interaction problems for Aminoglycosides and other nephrotoxic drugs?
What nursing interventions need to be done with Aminoglycoside Abx?
- Monitor: renal fxn
- Hearing loss
- peak & trough levels
- *Warn to use sunblock & protective clothing
What types of bacteria are Tetracycline Abx effective against?
Gram-positive & Gram-negative bacteria & many other organisms.
How do Tetracyclines effect the bacteria?
Bacteriostatic & Inhibit protein synthesis of bacteria
What are Tetracylines used for?
- fights Helicobacter pylori
- Treats acne (oral, topical)
- Treats chlamydia, mycoplasma & lyme disease
Tetracyclines are given via what routes?
Tetracyclines can be _____ acting, ______ acting, or _____ acting.
- Short - Tetracyline (Achromycin)
- Intermediate - Demeclocycline (Declomycin)
- Long - Minocycline (Minocin)
- Doxycycline (Vibramycin)
- *May be taken w/_____ _____ & food
What are the s/e & a/r of Tetracycline Abx?
- GI distress, photosensitivity, stomatitis
- Discolors permanent teeth in 3rd trimester of pregnancy & children under 8yrs old
- Blood dyscrasias
- *Thrombocytopenia & Hemolytic anemia
- *Pseudomembranous colitis
- CNS toxicity
What are the food & drug interactions with Tetracycline Abx?
- Antacids, Milk products (not Doxy), Iron preparations
- <effects of oral BC
- Digoxin absorption is ^, leading to toxicity
- ^effect of Aminoglycosides ????
What are the contraindications for the Tetracycline group of Abx?
Avoid during pregnancy & in children <8yrs old
What are the nursing interventions with Tetracycline Abx?
- Obtain C&S prior to drug
- Admin 1hr before or 2hr after meals
- Monitor: Kidney & liver fxn
- Store out of light & extreme heat
- Avise client to report superinfection
- Warn client to avoid milk*, Iron, antacids
- Tell client to use effective oral hydiene
Fluoroquinolones (Quinolones) Abx are a ______ spectrum abx.
How do Flouroquinolone Abx effect bacteria?
Bactericidal: interfere w/the enxyme DNA gyrase
What types of bacteria do Fluoroquinolone Abx work against?
What types of infections are Fluoroquinolone Abx used for?
- Bone & joint infxns
What routes are Fluoroquinolones given?
Name some Fluoroquinolone Abx.
- Levofloxaxin (Levaquin)
- Norflaxacin (Noroxin)
What are the s/e & a/r of Fluoroquinolone Abx?
- GI upset, rash, urticaria, tinnitius, photosensitivity
- Hematuria, crystalluria
- Pseudomembranous colitis
- ^^AST & ALT levels
What are the drug interaction problems with Fluoroquinolone Abx?
- Antacids <absorption rate
- Levoflaxacin ^ effect of oral hypoglycemics, theophylline & caffeine
- ^bleeding with Coumadin
What are the nursing interventions with Fluoroquinolones?
- Infuse IV over 60-90min
- ^fluid intake to >2000ml/d to avoid Crystalluria
- Check for superinfection
- monitor labs
What is the action of Sulfonamides?
- Inhibit bacterial synthesis of folic acid
What are Sulfonamides used in the TX of?
- Otitis media
- Respiratory Infections
What routes can Sulfonamides be given?
What is the short-acting Sulfonamides?
What are the intermediate-acting Sulfonamides?
- Sulfasalazine (Azulfidine)
- Sulfamethaxazole (Gantanol)
Explain how Trimethoprim works & what is it used for?
- An antibacterial agent that interferes w/bacterial folic acid synthesis just as sulfonamides do.
- Urinary tract anti-infective
When Trimethoprim & Sulfamethoxazole (sulfonamide) are combined, what occurs?
Synergistic effect; ^the desired drug response against gram-negative bacteria Proteus & E. coli.
Trimethoprim/sulfamethoxazole (TMP/SMZ) do what to the bacteria & what type of infections are they used for?
- Blocks bacterial protein synthesis
- Bactericidal effect
- TX: UTI, Otitis media, Intestinal infxns, Lower resp.tract ifxns, Prostatitis, Gohorrhea
- Routes: Oral, IV