Antibiotics

Question 1

what is Antibiotics

Answer 1

any compound (natural or synthetic) that inhibits the growth of, or actively kills micro-organisms

Question 2

what are the principles of Antimicrobial Therapy

Answer 2

Identification of pathogen
–>acid fast stain
Susceptibility testing and resistance
–>put antibodies in bacteria cultures and see which one is the best at eliminating the bacteria

Question 3

what are the types of antibiotics

Answer 3

1. beta-lactasms
2. Macrolides
3. Quinolones
4. Aminoglycosides
5. Tetracyclines
6. Sulfonamides
7. Glycopeptides

Question 4

What are 2 types of antibiotics action

Answer 4

bacteriocidal: kill bacteria

Bacteriostatic:
inhibit growth of susceptible bacteria, lead to bacteria death

Question 5

What are the Four common mechanisms of action of antibiotics

Answer 5

1. Interference with cell wall synthesis
2. Interference with protein synthesis
3. Interference with DNA replication
4. Acting as a metabolite to disrupt critical metabolic reactions inside the bacterial cell

Question 6

characteristic of Beta-Lactam Antibiotics

Answer 6

• Broad & most commonly used class of antibiotics
• has a B-lactam ring as the primary structure
• bactericidal
• Chemical manipulation of the side chain led to new agents with advanced spectrum of antimicrobial activity

Question 7

what are some beta-Lactam Antibiotics

Answer 7

• Penicillins
• Cephalosporins
• macrolides
• tetracyclines
• Carbapenems
• ->merepenem
• ->doripenem
• Monobactams
• ->Aztreonam

Question 8

What is the Mechanism of Action of penicillins

Answer 8

1. Penicillins enter the bacteria via the cell wall
2. Inside the cell they bind to penicillin-binding protein
3. Once bound, normal cell wall synthesis is disrupted
4. Result: bacteria cells die from cell lysis

*Penicillins do not kill other cells in the body

Question 9

What is the indication of Penicillins:?

Answer 9

*narrow spectrum

Prevention and treatment of infections caused by Gram-positive bacteria

Question 10

What is narrow-spectrum antibiotic

Answer 10

effective against only a specific group of bacteria.

Question 11

What is narrow-spectrum antibiotic

Answer 11

effective against only a specific group of bacteria.

Question 12

Examples of pencillins

Answer 12

amoxicillin
ampicillin
cloxicillin
methicillin

Question 13

how does Antibiotic Resistance work in bacteria

Answer 13

• bacteria secrete beta lactamase

- which therefore breaks down the B-lactam ring inactivating the antibiotic

Question 14

What is Staphylococcus aureus

Answer 14

a MRSA because it has beta lactmase

Question 15

features of Cephalosporins

Answer 15

• Structurally related to penicillin

- bactericidal via inhibiting cell wall synthesis

Question 16

What is the relationship between generation of Cephalosporins and its effectiveness?

Answer 16

increase in generation , less effectie against gram +ve

Question 17

what are the side effects Cephalosporins

Answer 17

• hypersensitivity( undesirable reactions produced by the normal immune system, including allergies and autoimmunity.)
• headaches, dizziness
• Nausea & Vomiting

Question 18

What are the 4 generation of Cephalosporins

Answer 18

1. First-generation cephalosporins
   - ->Wide variety of gram-positive organisms
2. Second-generation cephalosporins
   - ->Gram-positive and some gram-negative organisms
3. Third-generation cephalosporins
   - ->Active against most gram-negative organisms
4. Fourth-generation cephalosporins
   - ->Extended gram-positive and gram-negative coverage
   - ->for the sickest patients
5. fifth generation
   - ->effective against MRSA
   - ->gram +ve and -ve
   - ->not effective against ESBL

Question 19

What is ESBL

Answer 19

• EXTENDED-SPECTRUM BETA-LACTAMASE are Gram-negative bacteria that produce an enzyme beta-lactamase that has
• the ability to break down commonly used antibiotics, such as penicillins and
  cephalosporins and render them ineffective for treatment

Question 20

what is the Newest cephalosporin agents

Answer 20

cefepime, 4th generation

Broader spectrum of antibacterial activity than third generation, especially against gram-positive bacteria

Question 21

features of macrolides

Answer 21

• broad spectrum
• -> cover gram +ve, -ve , atypical

*bacteriostatic

Question 22

What are the side effect of macrolides

Answer 22

Upset GI

• need to take with food
• ->otherwise nausea, vomiting, dizziness and cramps

Question 23

what are some macrolides drugs?

Answer 23

• erythromycin
• azithromycin
• clarithromycin

Question 24

What is the MOA of macrolides

Answer 24

Prevent protein synthesis within bacterial cells

–>cell dies eventually

Question 25

What is the indication of macrolides

Answer 25

``` Strep infections (gram +ve) --> Streptococcus pyogenes ``` Mild to moderate URI (gram -ve) --> Haemophilus influenzae

Question 26

what is the characteristics of tetracycline

Answer 26

Bacteriostatic -->inhibit protein synthesis and cell growth broad spectrum drug Natural, semisynthetic

Question 27

indication of tetracycline

Answer 27

``` Gram-negative, gram-positive protozoa Mycoplasma Rickettsia Chlamydia syphilis Lyme disease ```

Question 28

What is the side effect of tetracycline

Answer 28

N, V & D binds to ca2 and mg2 - ->don’t use with milk, - ->kids (yellow stained teeth), -->pregnancy ( stops fetal bone growth)

Question 29

what are some tetracyclines drugs

Answer 29

oxytetracycline | minocycline

Question 30

features of Aminoglycosides

Answer 30

Bactericidal -->prevents protein synthesis Broad spectrum -->mostly gram-negative; some gram-positive * deal with Systemic infections(sepsis) Potent antibiotics with serious toxicities

Question 31

What are the toxcities comes with Aminoglycosides

Answer 31

nephrotoxicity, ototoxicity

Question 32

What is the indication of Aminoglycosides

Answer 32

- kill gram-negative bacteria | - used in combination with other antibiotics (beta lactams) for synergistic effect

Question 33

What are some example of Aminoglycosides drug

Answer 33

neomycin gentamicin streptomycin (TB) tobramycin (CF)

Question 34

features of Quinolones

Answer 34

bactericidial broad spectrum - gram-negative organisms and some gram-positive organisms

Question 35

what is the MOA of quinolones

Answer 35

-->alters DNA of bacteria

Question 36

what is the side effect of Quinolones

Answer 36

n, v & d prolongation of q-t interval liver & kidney toxicity arthropathy

Question 37

What is some drugs of Quinolones

Answer 37

``` ciprofloxacin norfloxacin ofloxacin levofloxacin gatifloxacin ```

Question 38

features of Sulfonamides:

Answer 38

Bacteriostatic action | -->Prevent synthesis of folic acid

Question 39

indication of Sulfonamides

Answer 39

Treatment of Urinary Tract infections --> caused by Enterobacter spp., Escherichia coli, Klebsiella spp (gram-ve) Staphylococcus aureus(gram -ve) -->Treatment of prophylaxis of Pneumocystis carinii pneumonia --> Upper respiratory tract infections

Question 40

features of vancoymic

Answer 40

Natural, bactericidal antibiotic **treat MRSA and gram +ve infection

Question 41

what is 1 down side of vancoymic

Answer 41

may cause ototoxicity and nephrotoxicity monitor blood levels to ensure therapeutic levels and prevent toxicity