Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

3028phm human pharm ii > Antimycobacterials > Flashcards

Antimycobacterials Flashcards

1
Q

List the relevant/important antimycobacterials

A

Rifamycins (antibacterials) = rifampicin, rifabutin

Other = ethambutol, isoniazid, pyrazinamide, streptomycin

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

What does isoniazid target?

A

Targets mycolic acid

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

What does ethambutol target?

A

Arabinogalactan

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

What does pyrazinamide target?

A

short chain fatty acid precursors

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

What does Rifampicin target?

A

RNA polymerase (beta subunit)

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

What is the MOA of Rifampicin?

A

Inhibits DNA-dependent RNA polymerase –> inhibiting transcription of single stranded RNA into DNA

Reserved for MRSA and mycobacterial infections (also meningitis and epiglottitis

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

What are some ADRs of Rifamycin?

A

Flushing, itching = self limiting
Orange/red discolouration of tears, urine, saliva, sweat, soft contact lenses

Wheeze, cholestatic jaundice, hepatotoxicity (common among TB drugs), blood dyscrasias

Neurological symptoms, pseudomembranous colitis

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

What are some allergic reactions to Rifampicin?

A

Rash, flu-like symptoms, haemolytic anaemia

Haemoglobulinaemia, acute renal failure

Risk = taking irregularly/intermittently, if restarted after interval w/out

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

What drugs interact w/ Rifampicin?

A

Induces CYP450

Reduces levels of = warfarin, theophylline, itraconazole, steroids, opioids, phenytoin, verapamil, contraception

Rifabutin has less interactions than rifampicin

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

What is the MOA of isoniazid?

A

Bacteriostatic against static bacteria
Bactericidal against actively dividing M/ tuberculosis

MOA: Reduces catalase-peroxidase –> inhibits synthesis of mycolic acid component of cell wall

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

What are the ADRs of isoniazid?

A

Hepatitis due to acetyl-hydrazine metabolite = fast or slow acetylation phenotypes

Peripheral neuropathy due to pyridoxine (B6) deficiency –> INH inactivates this vitamin

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

What drugs interact isoniazid?

A

Alcohol and rifampicin = inc risk of hepatotoxicity

Carbamazepine and phenytoin levels inc = INH is an enzyme inhibitor

Aluminium salts = INH is absorbed by them

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

What is the MOA/activity of pyrazinamide?

A

Targets short-chain fatty acid precursors

Active against bacteria within macrophages

Bactericidal against M. tuberculosis in acid pH

Activity declines with time = pH inc as inflammation dec

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

What are the ADRs of pyrazinamide?

A

Hyperuricaemia (competes w/ uric acid at PCT), polyarthralgia, nausea

Urticaria, itch, dysuria, hepatotoxicity, rash, allergic reactions

thrombocytopenia, acute porphyria crisis (can’t handle haem), acute gout

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

Name some C/I for pyrazinamide use

A

Significant liver disease

Porphyria

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

What are some precautions for pyrazinamide use?

A

Gout = pyrazinamide inhibits renal excretion of urate –> raises uric acid levels

Renal impairment = avoid in moderate/severe impairment –> accumulation of uric acid crystals

Diabetes = management becomes difficult

16
Q

What are some signs of asymptomatic pyrazinamide hepatotoxicity?

A

syndrome of fever

anorexia

malaise

liver tenderness

hepatomegaly

splenomegaly

17
Q

What are some signs of serious reaction associated with pyrazinamide?

A

Clinical jaundice

Massive hepatic necrosis

18
Q

When should someone on pyrazinamide see a doctor?

A

Continuous nausea

Vomiting

unusual tiredness

yellowing of skin or sclera

dark urine

pale faeces

19
Q

What class does ethambutol belong to and outline its indications?

A

Class = synthetic butanol derivative

Indication = mycobacterium tuberculosis, M. avium-intracellulare infections

20
Q

What is the MOA and target of ethambutol?

A

Bacteriostatic against mycobacteria

Inhibit RNA synthesis, targeting arabinogalactan

21
Q

Why is ethambutol not typically used in children?

A

Has a common side effect of optic neuritis

Children aren’t always able to voice changes in eye sight/vision

22
Q

List some ADRs for ethambutol

A

Optic neuritis

headache, confusion, disorientation, hallucination, malaise, N/V, anorexia, abdominal pain

Jaundice, peripheral neuritis, hyperuricaemia, acute gout, neutropenia, renal failure, other blood dyscrasias

23
Q

Describe the characteristics of ethambutol induced optic neuritis

A

Decreased visual acuity = usually reversible (if caught early)

Scotoma = blind spots in otherwise normal vision

Colour blindness

3028phm human pharm ii (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions