Bactericidal inhibitors of bacterial protein synthesis

Question 1

Aminoglycosides types

Answer 1

• gentamicin
• tobramicin
• bactericidal inhibitors of protein synthesis–> concentration dependent agents (require a certain concentration to be reached in order to have full effect)

Question 2

aminoglycosides uses

Answer 2

1) GRAM - (CRE)
2) severe gram - infections (multi drug resistant organisms)
3) some pre op

• Gram + and Gram -

Question 3

aminoglycosides US boxed warnings

Answer 3

1) nephrotoxicity- irreversible
2) ototoxicity - typically irreversible (ppl with renal dysfunction are more susceptible to this)
3) pregnancy- fetal harm
- these kind of limit use

Question 4

MOA of aminoglycosides

Answer 4

inhibits bacterial protein synthesis

bactericidal

Question 5

Routes of aminoglycosides

Answer 5

IV (can use IV formulation for inhalation for tobramycin- cystic fibrosis patients)

Question 6

Metabolism/ excretion of aminoglycosides

Answer 6

pharmacy to dose- peaks for concentration dependent killing, troughs to minimize toxicity

Question 7

Rare affect of aminoglycosides

Answer 7

aminoglycoside induced neuromuscular blockade –> paralyzes patients

Question 8

Antimetabolites (2)

Answer 8

1) sulfonamides

2) trimethoprim

Question 9

Sulfonamides (1)

Answer 9

sulfamethoxazole / trimethoprim (bactrim)
- inhibit folic acid synthesis

-antimetabolites

Question 10

sulfonamide uses

Answer 10

cellulitis, uti, Gram +, good MRSA coverage

MRSA, MSSA, Gram +

Question 11

sulfonamide MOA

Answer 11

inhibit folic acid synthesis

- trimethoprim combined with this inihibits folic acid synthesis via a different pathway

Question 12

sulfonamide Contradindications

Answer 12

history of drug induced immune thrombocytopenia

Question 13

ADR of sulfonamide

Answer 13

1) hyperkalemia (blocks Na channels in the distal nephron, inhibits potassium secretion, potentially fatal)
2) hypersensitivity reaction - delayed and immediate
- immediate- typical rash, angioedema, anaphylaxis
- delayed - stevens johnson syndrome , toxic epidermal necrolysis (severe forms of rashes)

Question 14

metabolism/excretion sulfonamide

Answer 14

Renal adjusment needed

Question 15

Sulfacetamide

Answer 15

topical for acne, bacterial infections, scaling dermatoses, ophthalmic infections

Question 16

Silvadene

Answer 16

silver sulfadiazine - topical for burn treatment- prevention and treatment of wound sepsis

Question 17

sulfadizine

Answer 17

toxoplasmosis treatment - first line

Question 18

Fluoroquinolones indications

Answer 18

• broad spectrum –> cover GRAM + and atypical organisms
• MOXIFLOXACIN (BROADEST) –> ANAEROBES
• do not cover MRSA
• Levofloxacin (levaquin)/ moxifloxican –> respiratory Fluoroquinolones
• Ciprofloxacin (CIPRO) –> non-respiratory Fluoroquinolones (belly button down)

-gram +, gram -, pseudomonas, atypicals and moxifloxacin does anaerobes, some MSSA

Question 19

US box warnings Fluoroquinolones

Answer 19

1) serious adverse reactions –> tendinitis and tendon rupture, peripheral neuropathy, CNS effects
2) Exacerbation of myasthenia gravis –> avoid in patients with MG

Question 20

MOA Fluoroquinolones

Answer 20

Promotes DNA strand breakage via inhibition of topoisomerase

Question 21

Routes of Fluoroquinolones

Answer 21

Oral (xr tablets/ solution)
IV
ophthalmic/otic

Question 22

Metabolism/excretion Fluoroquinolones

Answer 22

• require renal adjustment

- absorption decreased by POSITIVE CATIONS (2 hours before or 6 hours after)

Question 23

Fluoroquinolones ADRs (severe)

Answer 23

1) CNS effect/neuroexcitation
2) QT interval prolongation
3) tendon rupture/ tendinopathy
4) phototoxicity

Question 24

Metroidazole (flagyl) Indications

Answer 24

Anaerobic bacterial infections (bacterial vaginosis), trichomoniasis, surgical prophylaxis
- THE BEST ANAEROBIC AGENT

Question 25

US boxed warnings Metroidazole (flagyl)

Answer 25

carcinogenic in mice and rats

Question 26

Contraindications of Metronidazole (flagyl)

Answer 26

• first trimester pregnancy
• ***alcohol-disulfiram reaction **: bad to have alcohol with this drug. If you consume alcohol with this it will form a chemical bond that induces vomiting

Question 27

Routes of Metroidazole (flagyl)

Answer 27

• oral tab
• iv solution
• vaginal cream

Question 28

ADR Metronidazole (flagyl)

Answer 28

• nausea and headache

- metallic taste!!!! –> can linger for a long period of time

Question 29

metabolism/secretion of Metroidazole (flagyl)

Answer 29

hepatic adjustment –> reduce dose by 50% in severe liver impairment

Question 30

Rifampin Indications

Answer 30

TB, meningiococci elimination from nasopharynx
- alot of off label uses

• Gram +, Gram -, MSSA
• usually develops resistance if used alone

Question 31

MOA Rifampin

Answer 31

inhibits RNA synthesis (blocks transcription via DNA dependent RNA polymerase

Question 32

Contraindications Rifampin

Answer 32

• concurrent use of HIV and Hep C drugs

- MANY DRUG INTERACTIONS (strong inducer of CYP3a4 and other CYPS

Question 33

ADR Rifampin

Answer 33

discolors body fluids- red/ orange color

Question 34

Metabolism/ excretion Rifampin

Answer 34

no dosage adjustments

Question 35

Nitrofurantoin (MACROBID AND MACRODANTIN) Indications

Answer 35

UTIs and prophylaxis for recurrent UTIs

• Gram +, Gram -, MSSA

Question 36

Nitrofurantoin (MACROBID AND MACRODANTIN) MOA

Answer 36

inhibits protein, DNA, RNA and cell wall synthesis

Question 37

Nitrofurantoin (MACROBID AND MACRODANTIN) Contraindications

Answer 37

anuria, oliguria, or significant impairment of renal function, previous history of cholestatic jaundice or hepatic dysfunction with prior use

Question 38

Nitrofurantoin (MACROBID AND MACRODANTIN) ADR

Answer 38

well tolerated