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Flashcards in Antibiotics Deck (50):
1

Cell Wall Antibiotics

Beta Lactams
Glycopeptics

2

Protein Synthesis Inhibitors

30S
Tetracycline, Doxocyclin
Aminoglycosides (Tobramycin, Amikacin, Gentamycin)
50S
Clindamycin
Macrolides (Azithromycin, Clarithromycin, Erythromycin)
Linezolid

3

Nucleic Acid Inhibitors

Flouroquinolones
Metronidazole (DNA Damage)

4

Anti-Metabolites

Sulfonamides

5

Anti Tuberculosis

Isoniazid
Rifampin
Pyrazinamide

6

Beta Lactam Category

penicillins
cephalosporins
carbapenems
monobactams

7

Beta Lactam Mechanism

Inhibition of bacterial cell wall synthesis by acylating transpeptidases

Mechanism of Resistance: B-lactamase inhibitors

8

Side Effects of Beta Lactams

Generally well tolerated unless patient is hypersensitive/allergic and then can lead to rashes, fever and other bad things

9

Glycopeptics

VANCOMYCIN
MOA:
- Only effects gram + bacteria
- Inhibits cell wall synthesis (binds D-Ala-D-Ala terminus of pentapeptide

10

Resistance to Glycopeptics

Substrate modification (D-ala-D-ala to D-ala-D-lactate) through VanA transposon

11

Side Effects of Glycopeptics

10% of all cases
MINOR:
- Tissue irritation, chills, fever
MAJOR:
- Ototoxicity and Nephrotoxicity

12

Tetracyclines include ...

Includes:
- Tetracycline
- Doxocyclin
- Tigecycline

13

Tetracyclines work by ...

inhibiting protein synthesis. Bind irreversibly to the 30S subunit of the bacterial ribosome. Blocks the aminoacyl-tRNA to acceptor site on mRNA-ribosome complex

14

Tetracyclines resistance

Impaired influx or increased efflux by active transport protein
Ribosome protection via interfering proteins

15

Tetracyclines side effects

GI - nausea, vomiting, diarrhea
Bony structures - can be deposited in bones of growing fetus
Renal Tubular Acidosis
Hepatic function impairment in patients with hepatic issues

16

Aminoglycosides include ...

Tobramycin
Amikacin
Gentamycin

17

Aminoglycosides work by ...

Irreversibly inhibiting protein synthesis by binding the 30S. Interfers with the initiation complex, misreading of mRNA, breaks up polysome into nonfunctional monosomes

18

Aminoglycosides resistance

- production of transferase enzyme (inactivates Aminoglycosides)
- Impaired entry (porin protein mutation)
- Receptor protein on 30S is deleted or altered

19

Aminoglycosides side effects

Increase when drug is taken for more than 5 days!
OTOTOXICITY
NEPHROTOXICITY
RESPIRATORY PARALYSIS

20

Macrolides include ...

Erthromycin
Clarithromycin
Azithromycin

21

Macrolides works by ...

Inihibtion of protein synthesis by binding the 50S subunit (blocks exit channel)

Most effective against gram positive bacteria

22

Macrolides resistance

- Reduced permeability
- Production of Esterases that hydrolyze macrolides
- Ribosomal protection via inhibitory proteins

23

Macrolides Side Effects

Anorexia, nausea, vomiting, diarrhea

Erythromycin --> Acute cholestatic hepatitis and inhibits cytochrome p450

24

Linezolid works by ...

preventing bacterial protein synthesis by binding to 23S ribosomal RNA of the 50S subunit. Bacteriostatic

25

Linezolid resistance

primarily due to efflux pumps

26

Linezolid side effects

Hematogenic - duration-dependent bone marrow suppression, neuropathy, and optic neuritis
Serotonin Syndrome

27

Flouroquinolones include ...

Ciprofaxin, levofloaxin, moxifloaxin

28

Flouroquinolones works on ..

both gram positive and negative

29

Flouroquinolones works by ...

Inhibiting topoisomerase II (DNA gyrase) and topoisomerase IV
Interferes with transcription (II), translation (II), and chromosome segregation during mitosis (IV)

30

Flouroquinolone resistance

Target Modification
Target production
Drug Modification

31

Flouroquinolone side effects

Generally well tolerated
Contraindicated for patients with QTc interval prolongation
May damage cartilage (not usually recommended <18)
Tendonitis

32

Metronidazole used for ...

ANAEROBIC bacteria!!! C. Diff colitis

33

Metronidazole works by ...

Disturbing ETC, reduced by ferredoxin, results in products that are toxic to anaerobic cells

34

Sulfonamides

usually combined with inhibitor of dihydrofolate reductase (trimethoprim) for UTI

35

Metronidazole side effects

Nausea, diarrhea, stomatitis, peripheral neuropathy

AVOID ALCOHOL ... ADH inhibitor

36

Sulfonamides work on ..

Gram positive and negative

37

Sulfonamides work by ..

antifolate, many bacteria cannot use exogenous folate, must synthesize it from PABA and Sulfonamidesare PABA analogs

38

Sulfonamide Resistance

- Overproduction of PABA
- Production of different enzymes w/ low Sulfonamide affinity
- Impair permeability

39

Sulfonamide Side Effects

Megablastic Anemia, Leukopenia, Granulocytopenia
Nausea, Vomiting , Fever
Vasculitis, renal damage, CNS disturbance

40

Isoniazid

Most active drug for TB treatment

41

Isoniazid works by ...

- Inhibits my colic acid synthesis, an essential component of the cell wall
- Forms covalent bond with acyl carrier protein

42

Isoniazid resistance

Caused by over expression of inna gene, which encodes an NADH-dependent acyl carrier protein reductase
*Occurs often so a combination therapy is required

43

Isoniazid side effects

Hepatotoxic - may cause hepatitis.
Peripheral Neuropathy (give pyridoxine to prevent)

44

Rifampin

Used in conjunction with isoniazid

45

Rifampin works on ....

Both gram + and -

46

Rifampin works by ...

Binding beta subunit of bacterial RNA polymerase. Bactericidal for mycobacteria

47

Rifampin resistance

Point mutations in rpoB, the gene for B subunit of the RNA polymerase

48

Rifampin side effects

- Rashes, thrombocytopenia, nephritis
Strong induction of cyto p450 and thus increases rate of elimination of drugs

49

Pyrazinamide

Used in conjunction to isoniazid and rifampin

50

Aztreonam

Monobactam
Gram negative rod aerobes only