Pharmacology Chapter 33

Question 1

Antibacterial Drugs need what to work?

Answer 1

Selective toxicity

Question 2

Selective Toxicity

Answer 2

selective killing of the invading organism without damaging the host

Question 3

Why do bacteria invade human tissue?

Answer 3

To replicate they must have a supply of amino acids, sugars, and other substances

Question 4

Factors of bacterial infection that are harmful

Answer 4

The replicating bacteria compete with the host for essential nutrients
Release of toxins within the host
Signal immune response

Question 5

In what types of patients are bacterial most severe?

Answer 5

immunocompromised patient or those that are debilitated (ex. AIDS, cancer, transplant patients)

Question 6

Factors that affect the utilization of antibiotics

Answer 6

Spectrum
Patient Tolerance
Bacterial Resistance
Provider preference

Question 7

Cidal vs. Static

Answer 7

Cidal- kills or destroys bacteria

Static- halts the progression and allows the body to kill

Question 8

Mechanism of action: (all in this case have a greater affinity for bacterial components than mammalian or human cellular components)

Answer 8

1. Inhibition of cell was synthesis and function
2. Inhibition of bacterial protein synthesis
3. Inhibition of bacterial DNA/RNA

Question 9

Cell Wall Synthesis Inhibitors

Answer 9

peptidoglycans makes the bacterial cell wall rigid. Drugs can reduce production of this, thus weaken the cell wall, causing loss of hyperosmotic pressure
bacterial hydrolysis “beta lactam antibiotics”

Question 10

Most effective and important antibiotics currently available

Answer 10

Penicillins

Question 11

Penicillins

Answer 11

semisynthetic (broader spectrum); penicillinase resistant (amoxicillin/Clavulanate)

Question 12

Cephalosporins

Answer 12

1-4th generations- the > the # (generation) to more broad spectrum it becomes (can be used for those allergic to penicillins)

Question 13

Polymixin: MOA & AE

Answer 13

MOA: Punch holes in the bacteria cell walls via attraction to negatively charges phospholipids in the bacterial cell wall. Like a detergent. (Ex: polymixin B in topical Neosporin creams)

AE: Nephrotoxic (highly kidney damaging) - thus never administered orally

Question 14

Bacittracin

Answer 14

Activity: Mainly used for topical skin infections broad spectrum activity

Question 15

Aztreonam

Answer 15

Activity: narrow spectrum; only covers gram negative organisms (Ex. Enterobacter and pseudomonas)

Question 16

Carbapenems

Answer 16

broad spectrum antibiotics aka “big guns”; activity against gram positive, gram negative, and anaerobic bacteria; reserved for last line use; all administered IV

Three Kinds: Ertapenem, Imipenem, & Meropenem

Question 17

Ertapenem

Answer 17

broad spectrum; great for intra-abdominal infections; no pseudomonas coverage

Question 18

Imipenem is given with what? and for what reason?

Answer 18

Given with Cilastatin to prevent breakdown in the kidney

Question 19

Vancomycin

Answer 19

“Big Gun” antibiotic for severe gram positive infections or in cases of penicillin allergic patients.

Question 20

Adverse Effects of Cell Wall Synthesis Inhibitors

Answer 20

Hypersensitivity, rash, itching, anaphylaxis, gastrointestinal problems (diarrhea, nausea)

Question 21

Bacterial Protein Synthesis Inhibitors

Answer 21

Bacterial Protein Synthesis Inhibitors: block bacteria from making life sustaining proteins via binding to bacterial ribosomes.

Question 22

Aminoglycosides

Answer 22

Activity: mainly target gram negative organisms but have some activity for gram positive and anaerobic bacteria; narrow therapeutic index
AE: Use is limited due to adverse effects: kidney toxicity and ototoxicity (ringing or fullness in ears), and dizziness

Question 23

Tetracycline

Answer 23

Activity: activity against gram positive, gram negative, and atypical bacteria (rickettsia, spirochetes (lyme disease), chlamydia)
Anti-inflammatory and immunomodulatory effects for use in acne and rheumatoid arthritis
AE: GI distress, hypersensitivity, skin rashes, photosensitivity, teeth discoloration in children; not used in pregnancy

Question 24

Macrolides

Answer 24

Broad spectrum activity against gram positive and gram negative organisms
Drugs of choice in respiratory infections
“cidal” at high doses
AE: gastrointestinal disorders (azithromycin < clarithromycin < erythromycin) and hypersensitivity reactions (rash, itching)

Question 25

Chloramphenicol

Answer 25

broad activity against both gram positive and gram negative organisms Activity:Used last line for severe infections (haemophilus, osteomyelitis, rickettsial infections); only administered IV AE: blood dyscrasias, thrombocytopenia, and aplastic anemia

Question 26

Clindamycin

Answer 26

Activity: mainly gram positive and anaerobic activity AE: Diarrhea, nausea

Question 27

Linezolid

Answer 27

Activity: mainly works against serious gram positive cocci infections (skin and soft tissue and respiratory) AE: nausea, diarrhea, blood dyscrasias

Question 28

Bacterial DNA/RNA Synthesis Inhibitors

Answer 28

inhibit bacterial DNA and RNA and arrest growth and reproduction

Question 29

Fluoroquinolones

Answer 29

Activity:broad spectrum activity against gram positive and gram negative organisms. Ideal for UTI respiratory, STIs, GI infections, anthrax, & osteomyelitits AE: **causes tendon pain and inflammation; hold exercise until source of tendinopathy is determined (high risk in patients with kidney impairment, elderly patients, or concomitant steroid use)

Question 30

Sulfonamides

Answer 30

Activity: broad activity against gram positive and negative organisms MOA: disrupts folic acid production UTI, topical skin infections, burns (sulfadiazine, silver nitrate)

Question 31

Trimethoprim

Answer 31

MOA: Used with sulfonamide for UTI (can’t be used by itself) Activity: specifically block folate pathway in bacterial cells

Question 32

Dapsone

Answer 32

Activity: combined with rifampin for leprosy AE: causes hypersensitivity rxn

Question 33

Metronidazole

Answer 33

Activity: excellent for anaerobic infections; used for C. Diff AE: causes neuropathies, GI distress, reactions with alcohol

Question 34

Ethambutol

Answer 34

Activity: for tuberculosis AE: causes visual disturbances

Question 35

Rifampin

Answer 35

Activity: for tuberculosis and leprosy AE: causes red secretions (pee, cry red)

Question 36

Mupirocin

Answer 36

Activity: commonly used topical antibiotic for skin infections AE: may cause skin irritations

Question 37

Isoniazid

Answer 37

MOA: not fully understood; may possibly interfere with macronutrient metabolism in bacteria Activity: primary tuberculosis drug AE: peripheral neuropathy most common side effect

Question 38

Nitrofurantoin

Answer 38

MOA: produces toxic metabolite that destroys bacteria Activity: commonly used for UTI; safe to use for those with sulfa allergies AE: GI distress, headache numbness and fatigue

Question 39

Selection of an Antibiotic depends on

Answer 39

``` Organism Location and type of infection Patient factors (age, organ function, allergies) Prior drug exposure (resistance) Culture sensitivity Medication formulary ```

Question 40

What are the 4 Bacterial resistance mechanisms

Answer 40

Destruction of antibiotic by enzyme (ex. beta lactamases) Modification of target receptors (ex. Mutation of penicillin binding protein target site) Reduced cell penetration (aminoglycosides) Drug efflux pumps (macrolide antibiotics)