Exam 4-1 Flashcards
1
Q
Antibiotics
A
Medications used to treat bacterial infections
*Ideally, before beginning antibiotic therapy, the suspected areas of infection should be cultured to identify the causative organism and potential antibiotic susceptibilities
2
Q
Bacterial Morphology Shapes
A
- Coccus
- Bacillus
- Coccobacillus
- Fusiform Bacillus
- Vibrio
- Spirillum
- Spirochete
3
Q
Gram Positive Bacteria
A
- Actinobacteria
* Firmicutes
4
Q
Firmicutes
A
- Bacilli, order Bacillales
- Bacilli, order Lactobacillales
- Clostridia
- Mollicutes
5
Q
Actinobacteria
A
- Actinomyces
- Arthrobacter
- Corynebacterium
- Frankia
- Micrococcus
- Micromonospora
- Mycobacterium
- Nocardia
- Propionibacterium
- Streptomyces
6
Q
Bacilli, order Bacillales
A
- Bacillus
- Listeria
- Staphylococcus
7
Q
Bacilli, order Lactobacillales
A
- Enterococcus
- Lactobacillus
- Lactococcus
- Leuconostoc
- Pediococcus
- Streptococcus
8
Q
Clostridia
A
- Acetobacterium
- Clostridium
- Eubacterium
- Heliobacterium
- Heliospirillum
- Megasphaera
- Pectinatus
- Selenomonas
- Zymophilus
- Sporomusa
9
Q
Mollicutes
A
- Mycoplasma
- Spiroplasma
- Ureaplasma
- Erysipelothrix
10
Q
Gram Negative Bacteria
A
- Acinetobacter- Acinobacillus
- Bordetella- Brucella
- Campylobacter- Cyanobacteria
- Enterobacter- Erwinia
- Escherichia coli- Franciscella
- Helicobacter- Hemophilus
- Klebsiella- Legionella
- Moraxella- Neisseria
- Pateurella- Proteus
- Pseudomonas- Samonella
- Serratia- Shigella
- Treponema- Vibrio
- Yesinia
11
Q
Empiric therapy
A
Treatment of an infection before specific culture information has been reported or obtained.
12
Q
Definitive Therapy
A
Antibiotic therapy tailored to treat organism identified with cultures
13
Q
Prophylactic Therapy
A
Treatment with antibiotics to prevent an infection, as in intraabdominal surgery or after trauma
14
Q
Therapeutic Response
A
Decrease in specific signs and symptoms of infection are noted (fever, elevated WBC, redness, inflammation, drainage, pain)
15
Q
Subtherapeutic Response
A
Signs and symptoms of infection do not improve
16
Q
Antibiotic Therapy Cont.
A
- Superinfection
- Pseudomembranous colitis
- Host factors
- Genetic host factors
- G6PD
- Slow acetylation
- Allergic reactions
17
Q
Antibiotic: Classes
A
- Sulfonamides
- penicillins
- cephalosporins
- macrolides
- quinolones
- aminoglycosides
- tetracyclines
- others
18
Q
Antibiotic Therapy: Mechanism of Action
A
- Interference with cell wall synthesis
- Interference with protein synthesis
- Interference with DNA replication
- Acting as a metabolite to disrupt critical metabolic reactions inside the bacterial cell
19
Q
Actions of Antibiotics
A
- Bacterial: Kill bacteria
- Bacteriostatic: inhibit growth of susceptible bacteria, rather than killing them immediately; will eventually lead to bacterial death
20
Q
Antibiotics: Sulfonamides
A
One of the first groups of antibiotics
- sulfadiazine
- sulfamethoxazole
- sulfisoxazole
21
Q
Sulfonamides are often-
A
combined with another antibiotic
-sulfamethoxazole combined with trimethoprim (a nonsulfonaminde antibiotic), known as Bactrim, Septra, or co-trimoxazole (SMX-TMP)
22
Q
Sulfonamides: Mechanism of Action
A
- Bacteriostatic Action
- Prevent synthesis of folic acid required for synthesis of puriness and nucleic acid
- Do not affect human cells or certain bacteria- they can use preformed folic acid
- Only affect organisms that synthesize their own folic acid
23
Q
Sulfonamides: Indications
A
- Effective against both gram-positive and gram-negative bacteria
- Treatment of UTIs caused by susceptible strains of:
- Enterobacter spp., Escherichia coli, Klebsiella spp., Proteus vulgaris, Staphylococucus aureus
- Pneumocystis jiroveci pneumonia (PJP)
- sulfamethoxazole/trimethoprim (co-trimoxazole)
- Upper respiratory tract infections
24
Q
Sulfonamides: Adverse Effects-Blood
A
Hemolytic and aplastic anemia, agranulocytosis, thrombocytopenia
25
Sulfonamides: Adverse Effects: Integumentary
Photosensitivity, exfoliative dermatitis, Stevens-Johnson syndrome, epidermal necrlysis
26
Sulfonamides: Adverse Effects: GI
*N/V/D, pancreatitis
27
Sulfonamides: Adverse Effects: Other
*Convulsions, crystalluria, toxic nephrosis, headache, peripheral neuritis, urticaria
28
B-Lactam Antibiotics
* Penicillins
* Cephalosporins
* Carbapenems
* Monobactams
29
Penicillins
* Natural penicillins
* Penicillinase-resistant penicillins
* Aminopenicillins
* Extended-spectrum penicillins
30
Natural penicillins
-penicllin G, penicillin V
31
Penicillinase-resistant drugs
*cloxacillin, dicloxacillin, nafcillin, oxacillin
32
Aminopenicillins
-amoxicillin, ampicillin
33
Extended-spectrum penicillins
piperacillin, ficarcillin, carbenicillin
34
Penicillins was first introduced in
1940's
35
Bactericidal inhibits
cell wall synthesis
36
Penicillins kill a-
wide variety of bacteria
37
Bacteria produce enzymes capable of-
destroying penicillins
- these enzymes are known as beta-lactamases
- As a result, the medication is not effective
38
Chemicals have been developed to-
inhibit these enzymes:
- clavulanic acid
- tazobactam
- sulbactam
39
These chemicals bind with-
B-lactamase and prevent the enzyme from breaking down the penicillin, thus making the penicillin more effective
40
Penicillin B-lactamase inhibitor combination products
* ampicillin+ sulbactam= Unasyn
* amoxicillin+clavulanic acid=Augmentin
* ticarcillin+ clavulanic acid= Timentin
* piperacillin+tazobactam=Zosyn
41
Penicillins: Mechanism of Action
* Penicillins enter the bacteria via the cell wall
* Inside the cell they bind to penicillin-binding protein
* Once bound, normal cell wall synthesis is disrupted
* Result: bacteria cells die from cell lysis
* Penicillins do not kill other cells in the body
42
Penicillins: Indications
* Prevention and treatment of infections caused by susceptible bacteria, such as:
- Gram-positive bacteria
- Streptococcus spp. Entercoccus spp. Staphylococcus spp.
43
Penicillins: Adverse Effecs
* Allergic reactions occur 0.7% to 4%
- Urticaria, pruitus, angioedema
* Those allergic to penicillins have a fourfold to sixfold increased risk of allergy to other B-lactam antibiotics
* Cross-reactivity between penicillins and cephalosporins is between 1% and 4%
44
Penicillin: Common adverse effects
Nausea, vomiting, diarrhea, abdominal pain
45
Penicillins: Interactions
Oral contraceptives
46
Cephalosporins
* First generation
* Second generation
* Third generation
* Fourth generation
* Fifth generation (not yet marketed)
* Semisynthetic derivatives from a fungus
* Structurally and pharmacologically related to penicillins
* Bactericidal action
* Broad spectrum
* Divided into groups according to their antimicrobial activity
47
Cephalosporins: First Generation
*Good gram-positive coverage
*Poor gram-negative coverage
*Parenteral and PO forms
*Examples:
-cefadroxil
-cephradine
-cefazolin
-cephalexin
Used for surgical prophylaxis, and for susceptible staphylococcal infections
**cefazolin (Ancef and Kefzol): IV or IM
**cephalexin (Kefzol): PO
48
Cephalosporins: Second Generation
```
Good Gram-positive coverage
Better gram-negative coverage than first generation
Examples:
-cefaclor
-cefprozil
-cefoxitin
-cefuroxime
-loracabef
-cefotetan
```
49
cefoxitin (Mefoxin): IV and IM
- used prophylactically for abdominal or colorectal surgeries
- Also kills anaerobes
50
cefuroxime
- surgical prophylaxis
| - does not kill anaerobes
51
Cephalosporins: Third Generation
*Most potent group against gram-negative bacteria
*Less active against gram-positive bacteria
Examples:
ceftibuten
cefotaxime
ceftazidime
cefdinir
ceftizoxime
ceftriaxone
ceftazidime
52
ceftriaxone (Rocephin)
* IV and IM, long half-life, once a day dosing
* Elimination is primarily hepatic
* Easily passes meniges and diffuse into CSF to treat CNS infections
53
ceftazidime (Ceptaz)
* IV and IM forms
* Excellent gram-negative coverage
* Used for difficult to treat organisms such as Pseudomonas spp.
* Eliminate renally instead of biliary route
54
Cephalosporins: Fourth Generations
* Broader spectrum of antibacterial activity than third generation, especially against gram-positive bacteria
* Uncomplicated and complicated UTI
- cefepime (Maxipime)
55
Cephalosporins: Fifth Generation
* Ceftobipriole (not available)
* Broader spectrum of antibacterial activity
* Effective against a wide variety of organisms
- MRSA
- Pseudomonas spp.
56
Cephalosporins: Adverse Effects
* Similiar to penicillins
- Mild diarrhea, abdominal cramps, rash, pruritis, redness, edema
* Potential cross-sensitivity with penicillins if allergies exist
57
Carbapenems
* Very broad-spectrum antibacterial action
* Reserved for complicated body cavity and connective tissue infections
* May cause drug-induced seizure activity
- this risk can be reduced with proper dosage
* All given parenterally
58
Carbapenems: imipenem/cilastatin (Primaxin)
- used for treatment of bone, joint, skin and soft-tissue infections
- Cilastatin inhibits an enzyme that breaks down imipenem
* meropenem (Merrem)
* ertapenem (Invanz)
* doripenem (Doribax)
59
Monobactams
* aztreonam (Azactam)
- Synthetic beta-lactam antibiotic
- Primarily active against aerobic gram-negative bacteria (E. Coli, Klebsiella spp., Pseudomonas spp.)
- Used for moderately severe systemic infections and UTI's
60
Macrolides
* erythromycin (E-mycin, E.E.S)
* azithromycin (Zithromax)
* clarithromycin (Biaxin)
* dirithromycin
61
Macrolides: Mechanism of Action
* Prevent protein sythesis within bacterial cells
* Consider bacteriostatic
* Bacteria will eventually die
* In high enough concentrations, may also be bactericidal
62
Macrolides: Indications
*Strep infections
-Streptococcus pyogenes
(group A B-hemolytic streptococci)
*Mild to moderate URI and LRI
-Haemophilus influenzae
*Spirochetal infections
-Syphilis and Lyme disease
*gonorrhea, Chlamydia, Mycoplasma
63
Macrolides: Indications cont'd
azithromycin and clarithromycin
- recently approved for mycobacterium avium-intracellular complex infection (opportunistic infection associated with HIV/AIDS)
* clarithromycin
- recently approved for use in combination with omeprazole for treatment of active ulcer disease associated with Helicobacter pylori infection
64
Macrolides: Adverse Effects
* GI effects, primarily with erythromycin
- nausea, vomiting, diarrhea, hepatotoxicity, flatulence, jaundice, anorexia
- Newer drugs, azithromycin and clarithromycin: fewer GI adverse effects, longer duration of action, better efficacy, better tissue penetration
65
Ketolide
* telithromycin (Ketek)
- Only drug in this class
- Better antibacterial coverage than mactolides
- Active against gram-positive bacteria, including multi-drug resistant strains of S. pneumoniae
- Associated with severe liver disease
- Use is limited
66
Tetracyclines
* demeclocycline (Declomycin)
* oxytetracycline
* tetracycline
* doxycycline (Doryx, Vibramycin)
* minocycline
* tigecycline (Tygacil)
67
Tetracycline: Characteristics
* Natural and semisynthetic
* Obtained from cultures of Streptomyces
* Bacteriostatic-inhibit bacterial growth
* Inhibit protein synthesis
68
Tetracyclines: Info
* Bind (chelate) Ca2+, Mg2+, and Al3+ ions to form insoluble complexes
* Dairy products, antacids and iron salts reduce oral absorption of tetracyclines
* Should not be used in children under age 8 or in pregnant/lactating women because tooth discoloration can occur if the drug binds to the calcium in the teeth
69
Tetracyclines: Indications
* Broad spectrum
| - Gram negative and gram positive organisms, protozoa, Mycoplasma, Rickettsia, Chlamydia, syphilis, Lyme disease, acne
70
Tetracyclines: Adverse Effects
* Strong affinity for calcium
- Discoloration of permanent teeth and tooth enamel in fetuses and children, or nursing infants if taken by the mother
* May retard fetal skeletal development if taken during pregnancy
71
Tetracycllines: Adverse Effects/Alteration in intestinal flora may result in:
* Superinfection (overgrowth of nonsusceptible organisms such as Candida)
* Diarrhea
* Pseudomembranous colitis
72
Tetracylines: Adverse Effects/May also cause:
* Vaginal candidiasis
* Gastric upset
* Enterocolitis
* Maculopapular rash
