pharm exam 3 Flashcards
What needs to be done prior to starting a patient on antibiotics? (How are antibiotics chosen?)
-Culture: blood, sputum, wound, throat and see what grows – determines which bacteria
-Sensitivity: tells us what drug that microorganism is sensitive to and helps us identify what abx is best to use
When would the antibiotic be changed?
-Once culture comes back after 72 hrs and broad spectrum abx isn’t enough
What is the nurse’s role in this?
-Must obstain culture before we can start abx
-Cultures take 72 hrs and after 24-48 hrs we can start preparing stuff and giving broad spectrum abx
What factors promote drug resistant microorganisms?
-Overuse, not using it the entire time, viral infections, treating S/S and not actual cause, using broad instead of narrow spectrum, too low/not therapeutic dose, prophylactic use
antibiotics
not for viral infections, fever with unknown origin, sharing, using until you just feel better, preventing infections (in most cases)
ABX
IV ABX may need lab monitoring to determine dose is within therapeutic range and not causing toxicity, especially with abx with high potential of toxicity
-want concentration to stay within therapeutic range
PEAK = greatest concentration of the drug in the blood (30 min after infusion) (not above cause then toxicity)
TROUGH = lowest concentration of the drug in the blood (draw 30 min PRIOR to next infusion)
-High trough levels higher risk for serious SE
Next dose may be held and/or dose decreased
-In hospital we use trough because that tells us if were in therapeutic index and if dose is lasting – guides dosing
This is a NURSING RESPONSIBILITY !!!
If we give dose late, then change time of following doses, especially IV, because it can altar concentration
So if not giving drug on time, that can altar these results
peak and trough
ABX
AKA CDAD (C. Diff associated diarrhea)
Gram +, spore-forming, anaerobic bacillus
-Spores are shed in feces and often transferred to patients from healthcare workers that came into contact with a contaminated person or object
-Spores are resistant to temp changes, alcohol, and drying –can live on surfaces for weeks
Symptoms can be mild to very severe: Can even be fatal
CDI almost always preceded by use of ABX: Kill the normal flora in the gut and allow C. Diff to take over
c diff
ABX
Classified: 3 unformed stool in 24 period and stool sample must be positive
Treat: First thing you do if suspect c. diff; Stop the ABX that facilitated C. Diff overgrowth
-Begin an ABX that can eradicate C. Diff
–PO metronidazole for mild/moderate infection
–IV Vancomycin for severe infection
-May give both meds IV if complicated, severe infection
Prevent/NM: Use ABX responsibility-especially those that have a high risk of C. Diff
-Clindamycin
-Cephalosporins
-Fluoroquinolones
Private room, Strict contact isolation (PPE includes gloves, gown), Hand hygiene with soap and hot water, Decontaminate surfaces with appropriate agent (Bleach)
c diff (2)
ABX
Narrow spectrum: treats infections caused by strep, tetanus, syphilis, endocarditis (prevent) -Pneicillin G IV or IM -Penicillin V PO -oldest abx, least toxic, rendal excretion - decrease dose with renal impairment Broad spectrum: effective for H. Influenza, e. coli, salmonella, shigella -Ampicillin PO/IV -Amoxicillin PO -Rash, diarrhea, more likely with amp Extended spectrum: treats P. Aeruginosa -Piperacillin -often given in combo with other abx Combination products Ampicillin/sulbactam (Unasyn) Amoxicillin/clavulanate (Augmentin) Piperacillin/tazobactam (Zosyn)
Highest rate of allergic reactions
Most common drug allergy 3 types of allergic reactions 1. Immediate: 2-30 minutes -Anaphylaxis -Observe for 30 minutes after giving via injection -Treatment ?? 2. Accelerated: 1-72 hours 3. Delayed: days to weeks Other symptoms that indicate allergy are … DOCUMENT THE ALLERGY & SEVERITY Possible cross sensitivity to cephalosporins High occurrence of resistance
Pencillins
(drugs that weaken bacterial cell wall)
ABX
Methicillin-resistant staphylococcus aureus (MRSA)
-Gram + bacterium – colonizes skin and nostrils of healthy people
-Resistant to all types of PCN
HCA MRSA usually transmitted by healthcare workers and patients
-Vancomycin is the drug of choice
CA MRSA usually results in mild infection
-Skin-skin transmission
-Contact with contaminated objects
-Preferred treatment is trimethoprim/sulfamethoxazole (Bactrim), cycline ABX, or clindamycin
MRSA
ABX
1st generation: effective against Gram + -Cefazolin -Cephalexin -Use for staphylococci and streptococci 2nd generation: effective aginst gram + and moderate gram - -Cefoxitin -Only use for sensitive staphylococci 3rd gen: effective against broad spectrum, most frequently used -Cefdinir -Ceftriaxone -Use carefully to prevent resistant 4th generation: effective against very broad spectrum -Cefepime -use for resistant organisms 5th generation: effective against broad spectrum and MRSA -Ceftaroline -MRSA, HCA pneumonias
Most are given IM/IV (10 for PO use)
Hypersensitivities are common: Rash or anaphylaxis
Cross sensitivity with Penicillin so don’t use it*
Ceftriaxone can increase bleeding risk (prolonged use)
-Closely monitor if also taking …
NO ETOH – disulfiram effect
-N/V, flushing, palpitations, HA, sweating, chest pain, weakness, blurred vision, hypotension –> shock
All are excreted via renal system
-So…what should you monitor?
-Decrease dose if …
Cephalosporins
begin with ‘cef’
ABX
Narrow spectrum: gram + bacteria: effective against staph Aureus, MRSA, severe CDI (drug of choice for )
IV and for serious infections only
A/E: renal failure (avoid other nephrotoxic meds like NSAID), otoxicity, red man syndrome r/t rapid infusion
Monitor trough level*, IV site for extravasation, rate (rapid infection causes red man syndrome)
only given PO for c. diff
Vancomycin
ABX
Broad spectrum
Not frequently prescribed, resistance is common: used for acne (PO, topical), lyme disease (Doxycycline), h. pylori*
Higher occurrence of superinfection: monitor for development of severe and persistent diarrhea; yeast infection/thrush
A/E: discolors teeth (binds to calcium in developing teeth), teratogenic (don’t use in kids under 8 or when breast feeding), worsens renal impairment, photosensitivity
NM: absorption decreased by food, don’t give with calcium, milk products, iron, mag laxatives or antacids r/t significant decrease in absorption; don’t give to those with renal failure
Tetracylcine: broad spectrum
Doxycycline: long acting (safe for renal pts)
declined use r/t resistance
ABX
Erythromycin: broad spectrum
-A/E: free of serious toxicity, nausea, QT prolongation (rare)
-Alternative to PNC; food decrease absorption
Azithromycin: broad spectrum
-A/E: diarrhea, QT prolongation
-caution with warfarin (may enhance effects)
Clindamycin: broad spectrum
-A/E: severe CDAD* (can be fatal), diarrhea, rash
-Report diarrhea >5/day, watch for mucus or blood in stool
Macrolides
ABX
Broad spectrum; many bacterial strains now reistant
Main indication is UTI caused by e.coli
A/E: hypersensitivity is common (rash, photosensitivity), steven-johnsons syndrome (rare), stop immediately if rash occurs, hemolytic anemia
Trimethoprim/Sulfamethoxazole is frequently used: Bactrim, N/V, rash, crystalluria –> lots of fluids
Sulfonamides
ABX
Narrow spectrum for gram - bacilli
Used only for serious infections
Gentamicin, Tobramycin, Amikacin* (least likely to develop resistance)
Must be given IV
Toxicity (monitor through trough level) (inner ear)
Aminoglycosides
Broad spectrum; use for wide variety infections
Mild GI upset, dizziness, HA, superinfections (c diff, yeast infection), tendon rupture (rare - increased risk with corticosteroids, pain in ankle/feet then take it off)
Fluoroquinolones
the floxacins
abx
anti-protozoal med that will kill anaerobic bacterial organism
Usually given in combo with another ABX (active against aerobic bacteria)
Resistance is rare
A/E: Nausea, headache, dry mouth, metallic taste, GI upset, dark urine (harmless)No ETOH during tx and for 3 days after
metronidazole
