Antimycobacterial Drugs - (TB and Leprosy) Flashcards

1
Q

AE of Isoniazid

A

Lupus-like syndrome and Peripheral neuritis

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2
Q

MOA of Isoniazid

A

Prodrug is activated by KatG (mycobacterial catalase peroxidase) –> targets InhA and KasA –> decreased mycolic acid synthesis –> decreased cell wall synthesis

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3
Q

Isoniazid is a synthetic analog of ?

A

Pyridoxine; must supplement patient with Vitamin B6

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4
Q

True or False: Isoniazid is safe in pregnancy.

A

True

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5
Q

Name the Rifamycins

A

Rifampin, Rifabutin

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6
Q

MOA of Rifamycins

A

Bind to beta subunit of bacterial RNA polymerase –> block transcription and therefore RNA synthesis

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7
Q

AE of Rifamycins

A

Orange body fluids, proteinuria

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8
Q

PK/PD of Rifamycins

A

CYP450 inducers

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9
Q

PK/PD of Isoniazid

A

CYP450 inhibitor

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10
Q

True or False: Rifampin is safe in pregnancy.

A

True

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11
Q

Which forms of Mycobacteria are Rifamycins used against?

A

M. kansasaii, M. tuberculosis

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12
Q

DOC for Tuberculosis in HIV patients because of reduced CYP450 effects

A

Rifabutin

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13
Q

Resistance mechanisms against Rifamycins

A

rpoB gene mutations, decreased permeability

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14
Q

Indications of Rifamycins

A

Meningitis prophylaxis, latent TB in patients who cannot tolerate Isoniazid, combined with Vancomycin for MRSA

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15
Q

MOA of Ethambutol

A

Inhibits arabinosyl transferase

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16
Q

AE of Ethambutol

A

Reversible red-green colorblindness, hyperuricemia, neuritis

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17
Q

Resistance mechanisms against Ethambutol

A

emb gene mutations

18
Q

Indictations of Ethambutol

A

combination therapy with Pyrazinamide, Isoniazid, Rifampin

19
Q

Which forms of Mycobacteria is Ethambutol used against?

A

M. tuberculosis and M. kansasaii

20
Q

AE of Pyrazinamide

A

Non-gouty polyarthralgia, hyperuricemia

21
Q

Resistance mechanisms against Pyrazinamide

A

Resistant strains lack Pyrazinamidase, increased efflux

22
Q

MOA of Pyrazinamide

A

Enzymatically hydrolyzed to Pyrazinoic acid

23
Q

Is Pyrazinamide safe for use during pregnancy?

A

Yes, if benefits outweigh risk

24
Q

What are the first line drugs for TB?

A

Isoniazid, Rifamycins (Rifampin and Rifabutin), Pyrazinamide, Ethambutol

25
Q

What are the second line drugs for TB?

A

Amikacin (Aminoglycoside), Streptomycin (Aminoglycoside), Levofloxacin (3rd gen. Fluoroquinolone), Ethionamide

26
Q

True or False: 2nd line drugs for TB are safe for use in pregnancy.

A

False; all 2nd line Antimycobacterial drugs are teratogenic!

27
Q

MOA of Dapsone

A

Inhibits Dihydropteroate synthase –> decreases folic acid synthesis (like Sulfonamides)

28
Q

Besides Leprosy, which other disease can Dapsone be used to treat?

A

PCP

29
Q

Repository form of Dapsone

A

Acedapsone

30
Q

AE of Dapsone

A

Hemolytic Anemia (b/c it is sulfa-related), Erythema nodosum (treat with Steroids or Thalidomide)

31
Q

PK/PD of Dapsone

A

CYP450 Inhibition

32
Q

Phenazine dye that is bactericidal against M.leprae

A

Clofazimine

33
Q

MOA of Clofazimine

A

Binds DNA –> inhibits replication; may generate ROS

34
Q

AE of Clofazimine

A

Red-brown skin discoloration, Eosinophilic enteritis

35
Q

Treatment for pauci-bacillary skin lesions

A

Rifampin + Dapsone for 6 months

36
Q

Treatment for multi-bacillary skin lesions

A

Rifampin + Dapsone + Clofazimine for 12 months

37
Q

Treatment for latent TB

A

Isoniazid (6-9 months) + Rifampin (4 months)

38
Q

Treatment against M.kansasaii

A

Isoniazid + Rifampin + Ethambutol

39
Q

Treatment against M.marinum

A

2 drug combo: Rifampin, Ethambutol, Clarithromycin, Minocycline, Doxycycline, Sulfonamides

40
Q

Treatment against M.chelonae

A

Clarithromycin monotherapy

41
Q

M.avium complex

A

Clarithromycin + Ethambutol +/- Rifampin

42
Q

M. fortuitum

A

Amikacin, Cefoxitin, Levofloxacin, Sulfonamides, Imipenem