Antibiotics

Question 1

Should PO PCNs be taken with or without food? What’s the exception?

Answer 1

Without food. Especially Natural PCN VK.

Exception - Augmentin

Question 2

What percentage of systemic antimicrobial agents teach the anterior segment of the eye?

Answer 2

1-2%

Question 3

Which drugs are inhibitors of cell wall synthesis?

Answer 3

Beta-Lactams (PCN, Cephalosporins), Vancomycin and Bacitracin

Question 4

What is the mechanism of resistance for PCN?

Answer 4

Penicillinase - enzymes produced by bacteria that destroy PCN by cleaving the beta-lactase ring of the drug

Question 5

What is the chemical/drug used to overcome penicillin resistance?

Answer 5

Clavulanic Acid - decoy drug that binds to penicillinase and allows PCN to kill the bacteria

Question 6

PCN only distributes into the brain during ________.

Answer 6

inflammation. PCN will only penetrate the CNS if the pt has meningitis

Question 7

Which PCNs were formulated to delay absorption of the drug?

Answer 7

Benzathine and Procaine

Question 8

By what injection and how long will Benzathine stay in the body?

Answer 8

By IM injection in gluteus Maximus, for 10 days

Question 9

By what injection and how long will Procaine stay in the body?

Answer 9

By IM injection in gluteus Maximus, for 1-2 days

Question 10

What is the use for Benzathine and Procaine

Answer 10

STDs… non-compliant pts

Question 11

Natural PCN VK is administered how?

Answer 11

PO

Question 12

Natural PCN G is administered how?

Answer 12

IV

Question 13

Nafcillin and Dicloxacillin are what type of PCN medication?

Answer 13

Antistaphylococcal

Question 14

______ dose amoxicillin covers Strep Pneumonia

Answer 14

High

Question 15

Ampicillin/Sulbactam are used in what type of infections?

Answer 15

Mixed Nosocomial (hospital) infections

Question 16

Amoxicillin/Clavulanate (Augmentin) is used in patients that have ________ organisms

Answer 16

Beta-Lactamase producing organisms. (I.e. H. Influenzae)

Question 17

Antistaphylococcal PCNs are the drug for choice for _______

Answer 17

MSSA

Question 18

What are the uses for anti-staphylococcal PCNs?

Answer 18

Skin and soft tissue infections - usually community required

Question 19

Name the anti-pseudomonas PCNs… which of the 4 diseases do they cover… what are they used for?

Answer 19

Ticarcillin (Ticar) and Piperacillin (Pipracil)… pseudomonas aeruginosa … nasty gram neg bugs or with diabetes patients with nasty infections.

Question 20

What are the beta-lactamase inhibitors of anti-pseudomonal PCNs….

Answer 20

Ticarcillin + Clavulanate = Timentin

Piperacillin + Tazobactam = Zosyn

Question 21

What is Timentin and Zosyn used for?

Answer 21

Used in nosocomial infections with mixed etiology (i.e. diabetic foot infection, neutropenic fever

Question 22

What are the ADR of PCNs?

Answer 22

Hypersensitivity w/ cross reaction to cephalosporins

Diarrhea - especially augmentin

Question 23

What is the percentage of the pt being hypersensitive to cephalosporins if they’re hypersensitive to PCNs?

Answer 23

3-10% chance

Question 24

What generation of cephalosporins can penetrate the CNS through the BBB?

Answer 24

3rd Generation

Question 25

Cephazolin (Ancef) is most commonly used as a _______.

Answer 25

Surgical prophylaxis drug.. it's used to stop skin grafts

Question 26

What is the most common 1st gen. cephalosporin prescribed?

Answer 26

Cephalexin (Keflex).. use it pt has a PCN allergy

Question 27

Cefaclor (Ceclor) is what generation cephalosporin and treats gram negative or positive bacteria?

Answer 27

2nd generation, gram positive

Question 28

Cefoxitin (Mefoxin) treats gram neg. or positive bacteria? Is the enteral or parental?

Answer 28

gram negative, only parental 2nd generation cephalosporin

Question 29

Cefuroxime Axetil (Ceftin) provides what type of coverage?

Answer 29

Anaerobic Coverage

Question 30

3rd generation Ceftriaxone (rocephin) and cefotaxime (flaforan) cover which of the 4 diseases?

Answer 30

Streptococcus Pneumoniae, some STD

Question 31

3rd generation Ceftazidime (fortaz, tazicef) cover which of the 4 diseases?

Answer 31

Psuedomonas Aeruginosa

Question 32

What are the adverse drug rxns of cephalosporins

Answer 32

Hypersensitivity, Diarrhea, Cross reaction with PCN allergic pts

Question 33

What is oral vancomycin used for?

Answer 33

Gut infection

Question 34

Administering vancomycin by IV can help with which of the 4 diseases?

Answer 34

MRSA- both CA and HA.. but would rather use it for HA

Question 35

What are the adverse drug reactions to Vancomycin?

Answer 35

Hypersensitivity, Red Man Syndrome, Ototoxicity and Nephrotoxicity

Question 36

Is Bacitracin used systemically or ophthalmically?

Answer 36

Ophthalmic, comes in ointment and suspension

Question 37

How many times should a pt apply Bacitracin daily?

Answer 37

1-3 times a day

Question 38

What is the ocular use for Bacitracin?

Answer 38

Conjunctivitis

Question 39

Fluroquinoles are known for what type of ocular issue?

Answer 39

Retinal Detachments

Question 40

Name the 3 Systemic Respiratory FQs. Which of the 4 diseases do they treat?

Answer 40

Levofloxacin (Levaquin), Moxifloxacin (Avelox) and Gemifloxacin (Factive). They treat streptococcus pneumoniae.

Question 41

Name the 2 systemic FQs. Which of the 4 diseases do they treat?

Answer 41

Ofloxacin (Floxin) and Ciprofloxacin (Cipro) Psuedomonas Aeruginosa

Question 42

Which ophthalmic FQ has the best ophthalmic penetration? why?

Answer 42

Besifloxacin 0.6% susp. (Besivance)... more fat soluble

Question 43

What are the risk factors associated with the development of FQ resistance?

Answer 43

Pt is over 65 years of age, history of COPD, previous treatment with FQ

Question 44

In what type of pts should we avoid use of FQs? Why?

Answer 44

Pregnant and breastfeeding women, kids less than 18 years. FQs can cause cartilage damage and arthopathy

Question 45

Which group of agents can cause tendonitis, tendon rupture and retinal detachment?

Answer 45

FQs!

Question 46

What are the drug/food interactions of FQs?

Answer 46

Ciprofloxacin and levofloxacin have food/milk chelation interactions.. absorption will be decreased if taken with cationic food/beverages

Question 47

Tetracyclines are (better or worse) than FQs

Answer 47

Worse

Question 48

All tetracyclines are ______ absorbed after PO ingestin. Why?

Answer 48

incompletely. Tetracyclines are destroyed by acid in the stomach.. has chelation drug interactions

Question 49

T or F: Doxycycline has an anti-inflammatory mechanism?

Answer 49

True. Must take with food

Question 50

List the ADRs of Tetracyclines.

Answer 50

Gastric Discomfort (esp. doxycycline).. Binds to calcium in the teeth and bone (do not use in pregnant/breastfeeding women or children under 8)...Phototoxicity

Question 51

Name the 3 Systemic Macrolides

Answer 51

Azithromycin (Zithromax/Z-Pak), Clarithromycin (Biaxin) and Erythromycin

Question 52

Ophthalmic Azithromycin is good for what ocular disease?

Answer 52

Bacterial conjunctivitis - instill 1 drop 2x a day

Question 53

Which systemic macrolide is applied to every baby when they're born?

Answer 53

Erythromycin

Question 54

Which macrolide is the worst on the stomach?

Answer 54

Erythromycine (worst) >> clrithro > azithromycin

Question 55

What 2 macrolides are CYP450 3A4 inhibors

Answer 55

Clarithromycin and Erythromycin... problem occurs when taking 2 drugs in the same route

Question 56

High concentrations of Aminoglycosides are known to cause what type of toxicity?

Answer 56

Nephrotoxicity (kidney) and Ototoxicity (inner ear)

Question 57

Tobramycin and Gentamycin cover which of the 4 diseases?

Answer 57

Psuedomonas Aeruginosa

Question 58

Sulfa agent, Co-trimoxazole, covers which of the 4 diseases?

Answer 58

CA MRSA

Question 59

What are the ADRs of Sulfa-Agents?

Answer 59

Steven's Johnson Syndrome, Toxic epidermal necrolysis, phototoxicity, aplastic anemia, thrombocytopenia

Question 60

Metronidazole (Flagyl) covers which of the 4 diseases?

Answer 60

Anaerobes

Question 61

Which of the following drugs should be avoided while consuming alcohol which can cause a disulfiram rxn?

Answer 61

Metronidazole

Question 62

Clindamycin (Cleocin) covers which of the 4 diseases

Answer 62

CA MRSA, and its a great choice for cellulitis

Question 63

Vigamox 2.5mL/bottle = _____ drops?

Answer 63

~20 drops/mL = 50 drops

Question 64

When should a doctor use fortified antibiotics?

Answer 64

For sight-threatening infections (i.e. keratitis and corneal ulcers)