Term
| What are the 5 types of pathogens? |
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Definition
1. Bacteria
2. Atypicals (prions, mycoplasmas)
3. Virus
4. Fungi
5. Parasites |
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Term
| What factors influence the severity of a disease? |
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Definition
| Host response, portal of entry, pathogen "load", organism virulence, organism characteristics |
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Term
| What are some bacterial pathogenic characteristics? |
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Definition
| Rigid cell wall, reproduce by direct cell division, aerobic or anaerobic, some form spores, classified by shape & staining |
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Term
| Why are mycoplasmas difficult to treat with antibiotics? |
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Definition
| No rigid cell wall (where many abx's act) |
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Term
| Characteristics of Rickettsiae & Chlamydiae |
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Definition
| Rigid cell wall, intracellular obligate, may be transmitted by arthropod |
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Term
| What are viral pathogenic characteristics? |
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Definition
| Intracellular obligates (need host for reproduction), no cell structure, some have lipoprotein coat |
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Term
| What are fungi pathogenic characteristics? |
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Definition
| Ubiquitous in the environment, cause problems in immunocompromised ppl, common cause of tinea |
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Term
| What are the three types of parasites? |
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Definition
1. Protozoa - unicellular; malaria, dysentery, giardia
2. Helminths - worm like
3. parasitic arthropod - can be vectors of cause own problems; ticks, lice |
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Term
| Which type of microorganism is responsible for the majority of infectious human illnesses? |
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Definition
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Term
| How do antimicrobials destroy infections organisms w/o damaging host cells? |
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Definition
| By capitalizing on unique characteristics of the infection organisms' structure, requirements, or reproduction. |
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Term
| What factors might make it difficult for a drug to effectively work again a microorganism? |
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Definition
| Blood brain barrier, sequestration of organism (abscess or sinusitis, "clump"), colonization of foreign material in body ("distraction") |
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Term
| What factors affect drug treatment? |
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Definition
*Age - very young = immature system (no sulfa /tetracycline)
*Pregnancy/lactation = cross into placenta/breast milk
*Allergic rx
*Genetic Factors |
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Term
| What are the 3 possible antibiotic mechanisms of action? |
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Definition
1. Disrupt cell wall membrane = allow fluid in and cause cell lysis (pcn/cephalosporin)
2. Inhibit folic acid synthesis (sulfonamides)
3. Disrupt bacterial protein synthesis = act on ribosomes of bacteria |
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Term
| How does acquired resistance in organisms occur? |
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Definition
* Microbes create or improve drug-metabolizing enzyme
* Microbes stop taking up the drug
* Microbe receptors stop binding w/ drug
* Microbes may synthesize compounds to counter drug action
* spontaneous mutation
* bacterial conjugation = sharing DNA to broaden resistance |
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Term
| What are the three major consequences of drug resistance? |
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Definition
1. Suprainfections = secondary to primary infection
2. Nosocomial infecitons
3. Community resistance |
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Term
| What are the CDC guidelines for minimizing drug resistance? (11 things!) |
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Definition
1. Prevent infections = vaccines, remove caths
2. Target pathogens
3. Access the experts
4. Practice antimicrobial control
5. Use local data
6. Treat infection, not contamination
7. Treat infection, not colonization
8. Know when to say no to Vanco
9. Stop tx when infection is cured
10. Isolate the pathogen
11. Break the chain of contagion |
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Term
| What 3 factors are considered in antibiotic selection? |
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Definition
1. Identity of organism (microscopy, stains)
2. Susceptibility of organism (C&S)
3. Host (allergies, tx preparation, ADR, cost, compliance, ocp) |
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Term
| Why do many abxs reduce contraceptive efficacy? |
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Definition
| Estrogens & many abx are metabolized by CYP450 = compete for metabolic enzymes = less estrogen metabolized & available. |
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Term
What characterizes beta lactam abx?
What is their mechanism of action?
Examples? |
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Definition
presence of beta lactam ring in abx chemical structure
weakens becterial cell wall = increase osmotic pressure = pull water in = lyse cell
pcns, cephalosporins, related drugs |
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Term
| How do bacteria become resistant to beta lactam abx? |
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Definition
* bacteria produce enzyme beta lactamase
* cleaves beta lactam ring & inactivates drug |
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Term
| When are abx used prophylactically? |
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Definition
* Prior to surgery (cardio, orthopedic, GI)
* Prevention of bacterial endocarditis & cardiac valve disease
* Neutropenia & immune compromise
* chronic UTI |
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Term
What is the beta lactam prototype?
Uses?
Drug Facts? |
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Definition
| Penicillin, Gram+ cocci (esp. strep), neisseria meningitis, syphilis, prophylaxis bacterial endocarditis, many orgs. resistant (staph) |
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Term
| How is Pen G administered, absorbed, excreted? |
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Definition
| IM (very unpleasant) or IV, absorbed based on preparation, renal excretion |
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Term
| What other varieties of pcns are there? |
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Definition
Oral - Pn V, Pen VK
Penicillinase resistant pcns - narrow specturm against staph - Dicloxicillin, methiillin
Broad spectrum pcs - inactivated by beta lactamases - ampicillin, amoxicillin
Extended spectrum pcn - hospital use - tecracillin
Pcn mixed w beta lactamase inhib |
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Term
| What's the deal with Cephalosporins? |
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Definition
Similar to pcns
Disrupt cell wall synthesis
Often resistant to bacterial beta lactamase
Most widely used abx b/c broud specturm
Each "generation" more effective |
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Term
| Cephalosporin route? excretion? considerations? |
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Definition
Route based on individual drug
Renal excretion
Not given to pcn allergic cts
Can cause disulfiram rx c ETOH & bleeding
IV irritant |
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Term
| What are the two "big gun" beta lactam abx? administration? excretion? |
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Definition
IV Only
Renal excretion
Imipenem (Primaxin)
Vancomycin - drug of choice MRSA c.diff
Ototoxic side effects, thrombophlembitis, peak & trough levels |
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Term
| What is Clostridium difficele (C. difficele)? |
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Definition
Gram+ spore-forming bacteria in normal gut flora in 3% of ppl
Abx disrupt normal flora = C.diff overgrow
Toxins bind to interstinal mucosa = hemorrhage, inflamm, diarrhea
Usually stops c abx tx end
Most cases Nosocomial
Tx c Vancomycin = PO b/c gut flora |
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Term
What is Tetracyclines mechanism of action?
Broad or narrow spectrum? |
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Definition
Inhibit bacterial protein synthesis & suppress bacterial reproduction = bacteriostatic
Broud spectrum |
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Term
| What is the tetracycline minocycline commonly used for? |
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Definition
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Term
What is tetracycline a first line drug for?
What is Doxycycline commonly used for? |
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Definition
Mycoplasma pneumonia, Rocky Mountain spotted fever, Typhus, Periodontal disease
Doxycycline = Chlymydia |
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Term
| What are some adverse effects of tetracyclines? |
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Definition
GI Irritation = gastritis, N/V/D
Cannot be give c/in 2 hrs of milk, CA+, Iron, Mg or Alum.
Stains teeth = brown
Suprainfection = candida, C.diff
Photosensitivity
Hepatotoxicity |
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Term
What are macrolides mechanism of action?
Broad or narrow spectrum?
Three examples? |
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Definition
Inhibit bacterial protein synthesis
Broad spectrum
1. Erythromycin
2. Clarithromycin
3. Azithromycin (Z-pac) |
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Term
| When are macrolides commonly used? |
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Definition
Cts allergic to pcn
Legionnaires disease
Pertussis
Diptheria
Chlamydia
Mycoplasma
Strep peumonia |
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Term
| Benefits/Adverse effects of Erythromycin? |
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Definition
Cheap
N/V/D
Give c meals
CYP 450 interactions - NO c antihist, theophylline, carbamazepine, WARFARIN = Inc. risk c antiarrhythic rx, Ca channel blackers, antifungals, protease inhib |
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Term
| Benefit/Adverse effects of Azithromycin |
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Definition
Cheap-er
No GI effects
NOT administered c food
Slow elimination (bile) = loading dose ok
Short course of tx |
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Term
What is the risk of using Clindamycin?
What is it still the drug of choice for? |
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Definition
Pseudomembranous colitis
Gas Gangrene |
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Term
What are aminoglycocides mechanism of action?
Broad or narrow spectrum?
Major ADRs?
Administration?
Examples? |
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Definition
Disrupt bacterial protein synth = directly kill cells = bacteriocidal
Narrow spectrum (gram- aerobic)
Ototoxic & Renal toxic = peak & trough levels
IV administration unless in lumen of gut
Gentamycin, streptomycin, Amikacin |
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Term
Aminoglycoside prototype?
What is is used against?
ADRs? |
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Definition
Gentamycin
E.Coli, Klebsiella pneumoniae, Serratia, Proteus, Pseudomonas
Potent Oto & nephro toxicity = irreversible hearing damage = monitor for high trough levels
Increases neuromuscular blockade |
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Term
| Gentamycin drug-drug interactions? |
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Definition
Other ototoxic or nephrotoxic drugs (Furosimide)
Often given c pcns, but cannot be mixed in same solution
Peak & trough levels Q30min c IV admin. |
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Term
| Why are sulfonamides so special? |
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Definition
First abx ever
Cured preciously fatal diseases
Led to understanding of internal drug metabolism and bioavailability
Widespread resistance today |
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Term
What are sulfonamides mechanism of action?
Common uses? |
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Definition
Disrupt folic acid synthesis by bacterial cell
UTI
Sinusitis
MRSA
Off-label = headlice |
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Term
| What are the adverse effects of sulfonamides? |
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Definition
Hypersensitivity = rash, fever = STOP tx
Cross sensitivities = thiazide & loop diuretics, diamox
Blood dyscrasias = anemias
Kernicterus = bilirubin collects in brain = NEVER given to infants <2mo.
Renal damage = increase fluid intake
Photosensitivity |
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Term
| What drug works synergistically with sulfa? |
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Definition
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Term
| What drug is used as a urinary tract antiseptic? |
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Definition
Nitrofurantoin (Macrodantin) - works c mild cases
Broad spectrum bacteriostatic
Collects in urine |
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Term
What are fluoroquinolones used for?
Prototype?
What is it a DOC for? |
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Definition
Broad spectrum bacteriocidal
Infections in resp. tract, urinary tract, bone, joint, soft tissue
Ciprofloxin
DOC for anthrax |
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Term
What are the adverse effects of Ciprofloxin?
Drug interactions? |
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Definition
GI distress
Suprainfection
Tendon Rupture
Interacts c Cationic compounts = antacids, iron, dairy
Theophylline
Coumadin |
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Term
What is metronidazole (Flagyl) used against?
What is is the DOC for?
Prophylactic use?
Other uses? |
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Definition
Protozoal species
Only against obligate anaerobes
DOC for giardia, trickomonas, gardnerella, amebiasis, C.diff colitis
Prophylactic before GI or vaginal surgery
Multi drug combo for H. pylori |
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Term
What are the ADRs of Metronidazole (Flagyl)?
Drug interactions? |
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Definition
Metallic taste
GI distress (N/V)
Dark color to urine
Rare CNS paresthesias
Disulfiram reaction c ETOH |
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Term
| Fugal infections - systemic vs. topical? |
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Definition
Systemic rare = most common c AIDS/transplants = very dangerous
Topical common = tinea, onchomycosis, candida |
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Term
What is the anti-fungal prototype?
Mechanism of action?
Administration route? |
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Definition
Amphotericin B
Binds to sterol compounds in cell membrane (sometimes c human cholesterol too)
IV only |
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Term
| What are the adverse effects of Amphotericin B? |
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Definition
Infusion reaction = fever, chills, headache = prtreat c diphenhydramine
Thrombophlebitis
Nephrotoxicity
Hypokalemia
Bone marrow suppression |
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Term
What are the 'safer' antifunals?
Administration?
Broad or narrow spectrum? |
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Definition
Itraconozole (Sporanox)
Fluconazole (Diflucan)
IV or PO
Broad spectrum |
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Term
| What are the ADRs of Sporanox or Diflucan? |
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Definition
Cardiac suppression
Hepatic damage
CYP450 metabolism interactions c other drugs = antihistamines |
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Term
What interesting ADR occurs with antifungal ketoconazole (Nizoral)?
Drug interactions? |
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Definition
Sex hormone effects = ED, decreased libido irreg menses
Aminoglycosides
Flucytosine |
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Term
What drug is used to treat Hansens Disease (leprosy)?
ADR?
Drug interactions? |
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Definition
Dapsone
Discoloration of saliva, urine
Hepatotoxicity
GI distress
Warfarin, oc's protease inhibitors, rifampin |
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Term
| What drugs are commonly used for TB? |
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Definition
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