NR 566 Midterm Exam Study Guide

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NR 566 Midterm Exam Study Guide

- Things to know about each of the major antibiotic drug classes:

● Examples:

○ Bactericidal agents: “BANG Q R.I.P” - Beta-lactams, Aminoglicosides,

Nitroimidazoles (Metronidazole), Glycopeptides (Vancomycin), Quinolones, Rifampicin, Polymyxins (Colistin) ○ Bacteriostatic agents: “Ms. Colt” - Macrolides, Sulfonamides, Chloramphenicol, Oxazolidinones, Lincosamides (Clindamycin), Tetracyclines

Bactericidal antibiotics kill bacteria directly, and bacteriostatic antibiotics stop/weaken bacteria from growing.to enable the immune system to take hold of infection

-Things to know about each of the major antibiotic drug classes (MAKE FLASHCARDS)

● Aminoglycosides ● Cephalosporins ● Tetracyclines ● Penicillins ● Sulfonamides ● Fluoroquinolones

● Macrolides ● Carbapenems ● Lincosamides ● Glycopeptides

• Examples
• Contraindications and high-risk patients
• Know examples of each of the major antibiotic drug classes.
• Monitoring needs
• Which ones require renal dosing adjustments and how much (i.e., 25%, 50%, etc.)
• Patient education
• Lifespan considerations including pregnancy o Indications for use

Considerations:

● Renal/hepatic function: doses may need to be reduced. Consider creatinine clearance.● Age: dose adjustments may be required for pediatric and geriatric patients- weight- based may be appropriate.● Pregnancy and lactation: Be aware of teratogenic effects of certain classes of medications

● Recent antibiotic use: Be aware of possible drug-resistant bacteria

● Exposure history: travel, congregate care settings, close contacts

● Monitoring needs ○ Next, consider the syndrome, or presenting illness. -- What system is impacted? How aggressive is the infection? Consider non-bacterial causes of symptoms (i.e. viral, fungal, or non-infections) Carefully examine the clinical presentation of illness.

● Which ones require renal dosing adjustments and how much (i.e., 25%, 50%, etc.):

VII. Precautions: Antibiotics

• Antibiotics that require NO renal dose adjustment
• Azithromycin
• Ceftriaxone
• Clindamycin
• Doxycyline
• Linezolid
• Moxifloxacin
• Nafcillin
• Rifampin
• Agents to avoid in severe Chronic Kidney Disease
• Penicillin G (Myoclonus, Seizures, coma risk)
• Imipenem with cilastin (Seizure risk); Meropenem safe
• Tetracycline (exacerbates Uremia); Doxycycline safe
• Nitrofurantoin (peripheral neurotoxicity)
• Aminoglycosides (or close level monitoring if used)
• Amoxicillin

• Reduce to every 24 hours if GFR<10 ml/min
• Augmentin
• Reduce to every 24 hours if GFR<10 ml/min
• Do not use Augmentin 875/125 mg tabs if GFR<30 ml/min
• Cefazolin
• Reduce to every 12 hours if GFR<50 ml/min
• Reduce to 50% every 24-48 hours if GFR<10 ml/min
• Cefuroxime
• Reduce to 250 to 500 mg every 24 hours if GFR<10 ml/min
• Cephalexin
• Reduce to every 12-24 hours if GFR<10 ml/min
• Ciprofloxacin
• Reduce dose to 50-75% if GFR<50 ml/min
• Reduce dose to 50% or change to once daily dosing if GFR<10 ml/min
• Clarithromycin
• Reduce dose to 50-100% if GFR<50 ml/min
• Reduce dose to 50% or change to once daily dosing if GFR<10 ml/min
• Penicillin
• Reduce to 50% if GFR <30 ml/min
• Levofloxacin
• Reduce to every 24-48 hours if GFR<50 ml/min (or 500 mg loading dose, then 250

mg for subsequent doses)

• Reduce to every 48 hours if GFR<20 ml/min
• Avoid if GFR<10 ml/min
• Trimethoprim-Sulfamethoxazole (TMP-SMZ, Septra, Bactrim)
• Reduce to 50% if GFR <30 ml/min
• Avoid if GFR<15 ml/min
• Vancomycin
• Adjust dosing intervals based on drug level and Creatinine Clearance

It is important that antibiotics not be discontinued prematurely. Accordingly pts should be instructed to take their medication for the entire prescribed course, even though s/s may subside before the full course has been completed. Early discontinuation is a common cx of recurrent infection, and the organisms responsible for relapse are likely to be more drug resistant than those present when tx began.

Lifespan considerations including pregnancy

● Infants: are highly vulnerable to drug toxicity. BC of poor developed kidney & liver function. Use of Sulfonamides in newborns can produce kernicterus (a severe neurological disorder cause by displacement of bilirubin from plasma proteins ● Children/adolescents: the tetracyclines provide another example of toxicity unique to the young; these antibiotics bind to the developing teeth, causing discoloration.● Pregnant Women: Antimicrobial drugs can cross the placenta, posing a risk to the developing fetus. For example when Gentamicin is used during pg, irreversible hearing

loss in the infant may result. Ax used during pg may also pose a risk to the expected mother ● Breast feeding woman: Ax can enter breast milk, possibly affecting the nursing infant. For example: Sulfonamides can reach levels in milk that are sufficient to cause kernicterus in nursing newborn. As a general guideline, ax and all other drugs should be avoided by women who are breastfeeding. If antimicrobial therapy is considered the benefits should outweigh the risk ● Older adults: In the older adult, heightened drug sensitivity is due in large part to reduced rates of drug metabolism and drug excretion, which can result in accumulation of ax to toxic levels

- Community Acquired Pneumonia (CAP):

● CAP Is defined as pneumonia acquired outside hospital or healthcare facilities that results in inflammatory changes and damage to the lungs.● CAP is the type of pneumonia most often seen in primary care.

● Causative agents:

○ Most infections are caused by Streptococcus Pneumoniae (aka pneumococcus); gram positive

■ Also caused by:

● H. Influenzae (gram negative) ● Atypical bacteria - mycoplasma pneumoniae ● Viruses (e.g, influenza, respiratory syncytial virus)

○ The predominant organism in CAP depends on the age & overall health of the pt, Streptococcus Pneumoniae is the most common causative organism but other organisms should be considered when selecting tx agents.

● Diagnosed by:

○ Chest x-ray is the Gold Standard for CAP dx

● Treatment options:

○ Empiric Treatment when culture results are not available

■ If pt has NO comorbidities:

● First-line agents: Beta-lactam or doxycycline

○ Amoxicillin 1,000 mg PO TID x 5-7 days OR ○ Doxycycline 100mg PO BID x 5-7 days

● Alternative: Macrolides

○ Azithromycin (Z-pack) daily x 5 days ○ Clarithromycin BID or ER 1,000mg daily (do not use if >25% macrolide resistance ■ If patient has comorbidities (e.g. alcoholism; CHF; chronic heart, lung, liver, or kidney disease; abx in the last three months; diabetes; splenectomy/asplenia or high rates (>25%) of macrolide- resistant S.

pneumoniae:

● Combination therapy (beta-lactam & macrolide)