Infective Disease 2 Meds Questions Flashcards
(39 cards)
What are multi drug-resistant organisms? And which organisms do they include?
They are organisms that are resistant to one or more classes of antimicrobial drugs.
Include:
- MRSA (methicillin-resistant staphylococcus aureus)
- VRE (vancomycin-resistant enterococcus)
- ESBL- (extended-spectrum B-lactamases)
- and KCP- producing organisms (Klebsiella pneumonia carbapenemase)
What is therapeutic drug monitoring?
For which antibiotic class (and prototype med) is it important to apply to and why?
Therapeutic drug monitoring: is when the dosage of a drug is adjusted to maintain optimal levels that maximize drug efficacy while minimizing the risk of toxicity. The serum levels of that drug need to be monitored routinely.
Class of antibiotic : aminoglycosides (prototype: Gentamicin)
Why: because of the risk of nephrotoxicity and ototoxicity associated with that medication.
For which class of medication is trough level calculated, why and when? What is the therapeutic goal for the aminoglycosides trough level (lowest concentration)?
For the aminoglycosides (Gentamicin), to ensure adequate renal clearance of the medication and prevent risk of nephrotoxicity or ototoxicity.
Needs to be measured 30minutes prior to the next dose of medication. — therapeutic goal : at or below 1mcg/mL
If above 2mcg/mL = greater risk of toxicity
What is ototoxicity and which medication has a high risk for that AE?
Ototoxicity is toxicity of the ears, it usually manifests with some degree of temporary or permanent hearing loss, can also cause disrupt sense of balance.
Médication: aminoglycosides (Gentamicin) has a high risk of this toxicity.
Vancomycin also has that possible AE
Along with erythromycin,
What is nephrotoxicity ?
How is nephrotoxicity indicated (what are some of the signs and symptoms )?
Nephrotoxicity: toxicity of the kidneys which manifests by a decrease in kidney function. Degree may vary according to pt.
Nephrotoxicity: indicated by :
- lab test results showing a rise in serum creatinine levels suggests reduced creatinine clearance by the kidneys (indicate of decline in kidney function)
- proteinuria
- increased BUN (blood urea nitrogen)
What are the forms available for a Gentamicin (aminoglycosides) administration?
- IM, topically or ophthalmic
- Can be IV for certain circumstances (burns or shock)
- never PO due to poor absorption
Mechanism of action of aminoglycosides (Gentamicin)?
Bacteriostatic or bactericidal?
Sometimes given in combination with which class of antibiotics?
Mechanism of action: prevents protein synthesis in bacteria by binding to 30S ribosomes.
Considered bactericidal.
Often given with B-lactams (penicillins, cephalosporins, monobactams) or with vancomycin. — synergistic effect because B lactam break down cell wall and then aminoglycosides can access the ribosomes.
What are the contraindications for aminoglycosides (Gentamicin)?
- KDA
- pregnant women (cross placenta and cause fetal harm — so only given in life threatening situation)
- lactating women (can be distributed in breast milk)
- kidney problems
What are some other AE possible with aminoglycosides (Gentamicin) other than ototoxicity and nephrotoxicity?
- headache
- paresthesia
- vertigo
- skin rash
- fever
- overgrowth
- neuromuscular paralysis
What are some drug interactions that can occur with aminoglycosides (Gentamicin)?
Increase risk of nephrotoxicity with:
- Vancomycin
- cyclosporine
- amphotericin (fungizone)
Increase risk of ototoxicity with -loop diuretics (ex: furosemide)
Increase warfarin sodium toxicity due to effect of Gentamicin that kills normal intestinal flora (reduces the amount of Vitamin K that serves to balance effect of warfarin in the body)
How do fluoroquinolones (Ciproflaxin (Cipro)) work?
Are they bacteriostatic or bactericidal?
What forms are they available in?
- Work by altering the DNA of the bacteria which destroys the bacteria (Bactericidal)
Kill gram neg and some gram positive
Available: PO, injectable, ophthalmic, inhalation and IV
Most often: PO or IV
Indications for Ciproflaxin (Cipro)? (Fluoroquinolones med)
- Excreted by kidneys so good for complicated UTIs
- often used for respiratory, skin, GI, bone and joint infections.
- used for gram neg and some gram positive bacteria
what are some most common adverse effects of quinolones (Ciproflaxin)?
And what are the most worrisome?
Most common: headache, dizziness, insomnia, depression, restlessness, convulsions, nausea, contripation, vomiting, rash, pruritus, flushing, etc…
Most worrisome:
- Cardiac: prolonged QT interval, dysrhythmias (when taken with heart meds— so avoid mix)
- risk of tenditis and tendon rupture (in older adults or pts with kidney failure)
- muscle weakness
- resp: difficulty breathing and SOB
- CNS : stimulation causing seizures
What are some interactions with fluoroquinolones (Ciproflaxin)?
Cause reduction of oral absorption: so needs to take 1hr before or after taking quinolones
- antacids
- calcium preps
- iron preps
- magnesium preps
- Zinc preps
- sucralfate
- dairy products
- enteral feeding tubes
Cause reduction in kidney excretion of medication (prolong time in body):
- probenecid
Cause decrease antiviral efficacy of med:
- Nitrofurantoin
Affects anticoagulant function
Mechanism of action of clindamycin?
Bacteriostatic of bactericidal?
Clindamycin is a medication that inhibits protein synthesis.
- It can be bactericidal or bacteriostatic depending on the concentration of the drug.
What are the indications for clindamycin?
And what forms are they available in?
Treatment of chronic bone infection, GU tract infection, intraabdominal infection, anaerobic pneumonia and serious skin and soft tissue infections.
Available PO, Injectable and topical
What are the contraindications for clindamycin?
- patients with a known hypersensitivity reaction
- ulcerative colitis and enteritis
- infants younger than 1 month
What are some of the most common AE of clindamycin?
- N&V
- abdominal pain
- diarrhea
- pseudomembranous colitis (C. Diff) (necrotizing inflammatory bowel condition)
- anorexia
- neuromuscular blocking
What is an important interaction that can occur with clindamycin?
Can cause excessive neuromuscular blockade and respiratory paralysis when given with neuromuscular drugs (increase their action—> patients on both need to be monitored very closely)
Vancomycin:
- mechanism of action, bactericidal or Bacteriostatic?
And indication?
Given only PO or IV (poorly absorbed by PO so for GI infections)
Vancomycin works by binding to bacteria cell wall, inhibiting the cell wall synthesis causing death of the bacteria.
Bactericidal medication
Drug of choice for tx of: MRSA, C.diff, staph entérocolites infections and other gram positive bacteria.
Some common AE of vancomycin?
- nephrotoxicity (use with caution in pts with kidney dysfunction)
- ototoxicity
- neurotoxicity
- additive neuromuscular blocking effects (with neuromuscular blockers)
- red man syndrome (with rapid infusion— flushing, erythema, or itching of head, face, neck and upper trunk)
What AE can occur if the vancomycin is given at a rate too fast?
Over how much time should the vancomycin be infused to minimize risk of those AE?
- red man syndrome
- hypotension
- pain and muscle spasms in back and chest
- dyspnea
Infuse over 60min to minimize risks
Are trough levels measured with vancomycin IV?
If so what is the optimal blood level range for the trough level?
Yes, needs to be taken 30min before next dose.
Optimal blood level should be between 10-20mcg/mL for the trough level
What is the Mechanism of action of Linezolid (Zyvoxam)?
And what are its indications?
What forms available?
Mechanism of action: inhibits bacterial protein synthesis (Bacteriostatic)
Available PO and injectable
Indications:
- MRSA
- VRE
- health care pneumonia
- skin infections
- gram positive infections in infants and children
