Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Anti-Infectives Exam 2 > Lecture 8 - Antitubercular agents > Flashcards

Lecture 8 - Antitubercular agents Flashcards

(57 cards)

Start Studying
1
Q

1st line Antitubular Agents

A

RIPE

Rifamycins
Isoniazid
Pyrazinamide
Ethambutol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Rifamycins

A

Rifampin
Rifabutin
Rifapentine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Rifamycins MOA

A

Inhibit DNA dependent RNA polymerase

Bind to b-subunit of enzyme complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Rifampin ADME properties

A

Widely distributed, highly lipophilic

Hepatic metabolism, 3-4hrs 1/2 life

mostly feces excreted some in urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Rifabutin ADME properties

A

Widely distributed

Hepatic metabolism, 45hrs 1/2life

5 metabolites its metabolized to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Rifapentime ADME properties

A

High fat meals inc AUC & Max

Widely distributed

Hepatic metabolism, 17hr 1/2 life

Excreted mostly in feces 70/30

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Big reason for choosing one Rifamycin over another?

A

DI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Rifampin DI

A

has a bunch

Warfarin = inc clot risk
Cyclosporine, Tacrolimus
HIV protease inhibitors + NNRT inhib

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Rifabutin DI

A

way less DI, 50% of induction seen w/ rifampin

still has CYP3A4 tho

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Rifapentine DI

A

more potent inducer than rifabutin but less than rifampin

rarely used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Rifampin Adverse Reactions

A

Hepatitis main issue

GI, rash, Genitourinary = change colors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Rifabutin Adverse Reactions

A

Rash, Urine discoloration, GI, some Hematologic

higher incidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Rifapentine Adverse Reactions

A

Hepatic, Hematologic, Genitourinary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Rifampin role in therapy

A

1st line in pulmonary + extra pulmonary TB

resistance rapidly evolves if used alone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Rifabutin role in therapy

A

Rifampin alternative, as effective in drug susceptible TB

** used in pts w/ HIV if using protease inhibitors **

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Rifapentine role in therapy

A

approved for once weekly use in INH in continuation phase of therapy w/ HIV neg patients

** Avoid in HIV + patients on antiretroviral therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Isoniazid (INH) MOA

A
  1. inhibit synthetic pathways of mycelia acid
  2. inhibit catalase-peroxidase enzyme
  3. Bactericidal ( against activity growing) and bacteriostatic (against non-replicating organisms0
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Isoniazid (INH) ADME

A

well distributed, rapid absorption

excreted mostly in urine

Fast acetylators = lower 1/2 life
Slow acetylators = higher 1/2 life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Isoniazid (INH) Adverse effects

A

Hepatitis

Neurotoxic - peripheral neuropathy ~ 17% ( give Vit B to prevent)

Hypersensitivity reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Isoniazid Hepatitis risk factors

A 
Alcoholics
Preexisting liver damage
Reg women + women 3 months postpartum
Concomitant hepatotoxic agents
Active Hep B
HIV-seropositve pts on HAART
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Isoniazid DI

A

Phenytoin
Theophylline
Clopidogrel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Isoniazid Role in therapy

A

1st line, indicated for all clinical forms of TB, used in combo

Used alone for latent TB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Pyrazinamide (PZA) MOA

Study These Flashcards
A

Converted to pyrazinoic acid, lowering pH of environment

Inhibits fatty acid synthetase, involved in mycelia acid which are important for cell well

24
Q

Pyrazinamide (PZA) ADME

Study These Flashcards
A

well absorbed, widely distributed

crosses inflamed meninges

Hepatic metabolism, 9-10hr 1/2 life

25
Pyrazinamide (PZA) Adverse Reactions
Hepatotoxicity ~ 15% in trials in early trials at higher doses GI - N/V Urine retention ~ 50% Gout
26
Pyrazinamide (PZA) DI
Doesn't have any really BUT enhances hepatitis effects of Rifampin
27
Pyrazinamide (PZA) Role in therapy
1st line, essential component of multi drug 6month therapy ** Pts have to be on PZA for 1st 2 months ** Primary resistance is low, but if resistant to INH/Rifampin will probs be resistant to PZA
28
Ethambutol MOA
Interferes with cell wall biosynthesis Inhibits arabinosyl transferase (EmbB)
29
Ethambutol ADME
Well absorbed Widely distributed Hepatic metabolsim excreted urine and feces
30
Ethambutol Adverse Reactions
``` Neuropathy ** Retrobulbar optic neuritis** GI Hyperuricemia Hypersensitivity ```
31
Retrobulbar optic neuritis
Bilateral blurry vision and red/green color vision Slowly reversible TIW admin reduces the risk
32
Ethambutol DI
None
33
Ethambutol Role in therapy
1st line, 4th drug of combo protects against rifampin resistance, dropped once susceptibilities results are back
34
TB Treatment Algo
If think they have TB, start on RIPE Once susceptibilities back, E can be d/x if no drug resistance P has to be on of 1st 2 months, can take off after for rest **If dont get P in 1st 2 months, have to stay on therapy for 9 **
35
Bedaquiline ( Diarylquinoline) MOA
Inhibits ATP synthase through inhibition of proton transfer chain required for energy generation
36
Bedaquiline ( Diarylquinoline) ADME
Absorption inc w/ food Large Vd Hepatic metabolism
37
Bedaquiline ( Diarylquinoline) Adverse effects
** Nausea ~ 38% QTc prolongation Black box for Cardiac toxicity/sudden death
38
Bedaquiline ( Diarylquinoline) Black Box
"Only use when an effective treatment regime cannot otherwise be provided"
39
Clofazimine MOA
Prodrug, originally anti-leporsy exactly mechanism not well understood causes accumulation of ROS radicals and cause cell death basically
40
Clofazimine ADME
Absorption variable, inc w/ food Highly Lipophilic No hepatic metabolism
41
Clofazimine Adverse effects
** Pigmentation changes = pink/brown/black color GI = abdominal pain
42
Clofazimine DI
QTc prolonging effects
43
Cycloserine MOA
Inhibit bacterial cell wall synthesis by competing w/ amino acid (D-alanine) for incorporation into bacterial cell wall
44
Cycloserine ADME
Mostly GI absorption Widely distributed most body fluids Hepatic metabolism Highly urine excretion
45
Cycloserine Adverse effects
Cardiac effects CNS Skin Hepatic
46
Cycloserine DI
Minimal
47
Ethinamide MOA
Inhibits Peptide synthesis results in impairment of cell wall synthesis
48
Ethionamide ADME
essentially complete absorption Widely distributed, Vd 93.5L Prodrug, extensive hepatic metabolism
49
Ethionamide Adverse effects
``` Cardiovascular- ortho hypotension CNs SKin Hepatic GI ```
50
Ethionamide DI
minimal
51
Streptomycin MOA
Interferes w/ translation of mRNA transcripts Bind to S12 protein, part of 30S complex inhibits synthesis of mycobacterial proteins
52
Streptomycin ADME
Usually given IM, PO poorly absorbed Distributes into tissues/fluids except CNS No hepatic metabolism Urine excretion
53
Streptomycin Adverse effects
Nephrotoxicity Auditory + Vestibular toxicity Hypersensitivity reactions
54
Pretomanid MOA
Cell-wall lipid biosynthesis inhibitor inhibition of mycelia acid synthesis Formation of nitrogen reactive species
55
Pretomanid ADME
Well absorbed Distributes throughout body + CSF Urine excretion
56
Pretomanid Adverse effects
``` Pretty high change of Peripheral neuropathy Headache GI Musculoskeletal increased LFTs ```
57
Therapy for MDR-TB
1. pick 1 later-get Fluoroqinolone (Levo-/Moxifloxacin) 2. Both Bedaquiline + Linezolid 3. Both Clofazimine + Cycloserine/terizidone 4. If cant get those 5 + susceptible, do Amikacin + Streptomycin 5. If cant do injectable, do Delamanid, Pyrazinamide, Ethambutol

Anti-Infectives Exam 2 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions