Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
65 Cards in this Set
- Front
- Back
What is minimum inhibitory concentration (MIC)?
|
• minimum amount of antimicrobial agent needed to inhibit growth of bacteria
• assists in selecting appropriate antimicrobials |
|
What is the difference between bacteriocidal and bacteriostatic antibiotics?
|
• Cidal: antimicrobials that act by killing the microbes (ex. commonly use bacteriocidal antibiotics to treat bacterial endocarditis)
• Static: antimicrobials that inhibit microbial replication and growth |
|
What is the definition of narrow, extended, and broad spectrum antibiotics?
|
• Narrow Spectrum: one organism
• Extended Spectrum: various organisms (ex. gram +/-) • Broad Spectrum (ex. gram +/-, anaerobes, atypicals) |
|
How are most antimicrobials excreted by the body?
|
by the kidneys
|
|
Name 2 drugs that do not require dosage modifications for patients with renal failure.
|
• erythromycin
• chloramphenicol |
|
What are antimicrobials that require mild dose reductions for patients with renal failure?
|
• Cephalosporins
• Clindamycin • PCN • Rifampin |
|
What are antimicrobials that require major dosage reductions for patients with renal failure?
|
• aminoglycosides
• Vancomycin |
|
What are antimicrobials that should be avoided in patients with renal failure?
|
• Nitrofurantin
• Sulfonaides • tetracylcines |
|
What is a major cause of bacterial resistance?
|
Beta-Lactamase
|
|
What is the most common type of Beta-lactamase enzyme?
|
penicillinase
|
|
What are complications of antimicrobials?
|
• Hypersensitivity reactions (ex. allergic rxns, photosensivity, or infusion-related rxns)
• Direct Toxicity (on the site where the drug acts) • Superinfections: caused by inappropriate treatment, non-compliance, or when endogenous bacteria (the good bacteria) is killed |
|
Give an example of a bacteria that appears as diplococci
|
Neisseria
|
|
Give an example of an aerobic gram-positive rod and an anaerobic gram-positive rod
|
• Aerobic: Listeria
• Anaerobic: Clostridium |
|
List examples of aerobic gram-positive cocci
|
• Staph. Aureus
• Staph. Epidermis • Streptococcus • Strep. Pneumoniae • MRSA • Enterococcus |
|
Give examples of anaerobic gram-positive cocci
|
• peptococcus
• peptostreptococcus (found in the mouth) |
|
List examples of aerobic gram-negative rods
|
• Acinetobacter
• Citrobacter • E. Coli • Enterobacter • H. Flu • Proteus • Pseudomonas • Salmonella • Serratia • Shigella |
|
Give 2 examples of anaerobic gram-negative rods
|
• Bacteroides Fragilis (common in abdominal/diarrhea related illnesses)
• Bacteroides Melaninogenicus |
|
List examples of gram negative cocci
|
• Moraxella catarrhalis
• Neisseria gonorrhea • Neisseria meningitidis |
|
List examples of atypical bacteria
|
• Chlamydia pneumonia
• Chlamydia trachomatis • Legionella • Mycobacterium tuberculosis • Mycobacterium (MAC) • Mycoplasma pneumoniae |
|
Give 2 examples of protozoa
|
• Pneumocysitis Carinii
• Toxoplasma gondi |
|
What is the drug of choice for Pneumocystis carinii?
|
Bactrim
|
|
List examples of fungi
|
• Asperigillus
• Blastomyces • Candida • Cryptococcus • Histoplasma |
|
Are sulfonamides bacteriocidal or bacteriostatic?
|
bacteriostatic
|
|
What is the MOA of sulfonamides?
|
inhibits bacterial synthesis of folic acid
|
|
What is the role of PABA (p-aminobenzoic acid) in the MOA of sulfonamides?
|
• PABA is an essential metabolite for the synthesis of folic acid by plants and many microrganisms
• PABA is the target of many sulfonamide drugs |
|
What is the role of folic acid in the body?
|
• Folic acid is one of the two major single-carbon carriers of the body
• essential for DNA synthesis |
|
Give examples of anatgonists to PABA
|
• Sulfones (used to treat leprosy): an example of a sulfone is Dapsone which is used in HIV patients who are allergic to Bactrim
• Para-aminosalicylic acid (2nd line antitubercular agent) |
|
Describe the kinetics (absorption, distribution, metabolism, elimination) of sulfonamides
|
• A - very well absorbed; can be taken orally
• D - crosses blood-brain barrier; passes into all body fluids • M - metabolized by acetylation (good for the elderly) • E - acetyllated metabolites are renally filtered (does require dosage adjustment for renal insufficiency) |
|
What are adverse effects of sulfonamides?
|
• hypersensitivity reactions (Steven Johnson Syndrome)
• agranulocytosis • hemolytic anemia (tesdt for G6PD deficiency) • hypoglycemia • jaundice (in adults) • kernicterus |
|
What are causes of resistance with sulfonamides?
|
• altered enzyme (mutations)
• increased drug inactivation • increased PABA synthesis (due to overuse of sulfonamides) |
|
What is the MOA of Trimethoprim?
|
• inhibits formation of tetrahydrofolic acid
• inhibits dihydrofolate reductase |
|
What are characteristics of Trimethoprim?
|
• can be used alone or in combination with sulfas
• bacteriostatic • bacteria can develop resistance due to the drug's reduced affinity to the enzyme |
|
What are adverse effects of Trimethoprim?
|
Folic Acid deficiency
* often given folic acid supplementation |
|
What are uses of sulfonamides?
|
• Burns
• Chlamydia • Extended spetrum (gram + and gram -) • Meningococcal meningitis (drug can cross the blood-brain barrier) • Penicillin-sensitive patients • Pneumocystis carinii & Toxoplasmosis (for treatment or prophylaxis) • Pulmonary infection • Salmonella • UTI |
|
What is the MOA of penicillins?
|
• inhibits bacterial wall synthesis by binding and inactivating proteins in the bacterial membrane that regulates cell wall biosynthesis
• PCN binding protein catalyzes the formation of cross links in the peptidoglycan • PCN binding often causes cell lysis • inhibits transpeptidase (which contribute to cell wall strength) |
|
Penicillins are ineffective for what types of organisms?
|
• only effective against organisms that synthesize peptidoglycan cell wall
• not effective againsts viruses, fungi, or mycobacterium |
|
What are the general types of penicllins?
|
• Natural penicillins
• Antistaphylococcal penicillins • Extended spectrum penicillins • Anti-pseudomonal penicillins |
|
Give examples of natural penicillins
|
• Penicillin G
• Penicillin V |
|
Give examples of the antistaphylococcal penicillins
|
CONDOM drugs
• C - Cloxacillin • O - Oxacillin • N - Nafcillin • D - Dicloxacillin • M - Methicillin |
|
Give examples of extended spectrum penicillins
|
• Ampicillin OR Ampicillin + Sulfbactam (Unasyn)
• Amoxicillin OR Amoxicillin + Clavulanic Acid (Augementin) |
|
Give examples of anti-pseudomonal penicillins
|
• Carbecillin
• Piperacillin or Pipercillin/Tazobactam (Zosyn) • Ticarcillin OR Ticarcillin/Clavulanic (Timentin) |
|
Penicillin G is effective against what types of organisms?
|
• gram +/- cocci
• gram + bacilli • spirochetes |
|
What are the available formulations of Penicillin G?
|
PO, IM, or IV
|
|
Why is Penicillin G, when administered IM, given with procaine?
|
Penicillin G is very painful
|
|
A single shot Benazthine Penicillin G can be used to treat what?
|
gonorrhea
|
|
The anti-staphylococcal penicillins (CONDOM drugs) are used to treat what type of bacteria?
|
penicillinase producing bacteria
|
|
True/False: Nafcillin should not be used in patients with hepatic failure
|
• Nafcillin should not be used in patients with liver failure, becuase the drug is metabolized entirely by the liver.
• The correct answer is: True |
|
Which CONDOM drug is the best absorbed PO agent?
|
Dicloxacillin
|
|
Which CONDOM drugs DO NOT require renal dosage adjustment?
|
• Cloxacillin
• Oxacillin • Nafcillin • Dicloxacillin * Methicillin is excreted by the kidney and require dose adjustment w/ renal failure |
|
Name a side effect of Nafcillin
|
bone marrow suppresion
|
|
Name a side effect of all the penicillins
|
interstitial nephritis
|
|
What structurally distinguishes amoxicillin/ampicillin from Pencillin G?
|
an amino group added to the Penicillin G ring
|
|
What is the spectrum of activity of Ampicillin & Amoxicillin?
|
• extended spectrum of activity
• Gram +/- (looses some gram + coverage, used more for gram negative bacteria) |
|
What bacterias are treated with Ampicillin or Amoxicillin?
|
• E. Coli
• Neisseria • Proteus • Salmonella • Shigella Expanded to gram negative: Klebsiella & Hemophillus |
|
What are the available formulations of Ampicillin?
|
IV (preferred), but can be taken orally
|
|
Name a side effect of Ampicillin
|
diarrhea
|
|
Ampicillin PO is a good agent for the treatment of what?
|
Salmonella or shigella poisoning
|
|
What are available formulations of Amoxicillin?
|
only PO
|
|
What are the most common anti-pseudomonal penicillins used in a hospital?
|
Pipercillin & Ticarcillin
|
|
What organisms do the anti-pseudomonal pencillins cover?
|
• DOC for non-meningital pseudomonas
• covers gram-negative bacilli and pseudomonas • less effective aginst gram-positive organisms |
|
What drug should be used with Pipercillin or Ticarcillin for double coverage?
|
Tobramycin (aminoglycoside)
|
|
What are side effects of Carbecillin and Ticarcillin?
|
• hypokalemia
• hypernatremia (drugs have an increased sodium load) |
|
Carbecillin and Ticarcillin are not good agents for patients with what disease states?
|
HTN & CHF (because of the increased sodium load)
|
|
What are adverse effects of Pencillins?
|
• C. Dificile
• GI upset • Nausea/Vomiting • Rash • Steven Johnson Syndrome • Superinfection (overgrowth of fungi) * allergies are caused by haptens |
|
What is beta-lactamase?
|
• a common enzyme that hydrolyzes the beta-lactam ring, rendering the drug inactive
• causes resistance to pencillins |