CD 14 Flashcards

1
Q

Fungal infections Associated with

A

Skin
Mucous membranes
but Minor in healthy people

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2
Q

Fungal infections serious when

A
Systemic infections
Tinea pedis (Athlete’s foot)
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3
Q

Does Fungi are complex?

A

complex and evolved than bacteria

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4
Q

Do fungi is Clinically important?

A

Yes and Opportunistic pathogens

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5
Q

What is Amphotericin B?

A
  • Polyene antibiotic
  • Binds to ergosterol in fungal membrane
  • Helps to penetrate the wall
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6
Q

What is the Pharmacokinetics of Amphotericin (B)?

A

Used topically, systemic i.v. infusion

Excreted via by kidneys

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7
Q

What are the Unwanted effect of Amphotericin (B)?

A

Renal toxicity (80% of patients)
Hypokalemia (20%)
thrombophlebitis (Blood clots)

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8
Q

What are the clinical Usages of Amphotericin (B)?

A

Candida oesophagitis (HIV/AIDS)
Mucormycosis (weakened immune system e.g. organ transplant)
Meningitis

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9
Q

What is the mechanism of Nystatin?

Pharmacokinetics of Nystatin

A

Nystatin binds to ergosterol, a major component of the fungal cell membrane.It forms pores in the membrane that lead to K+ leakage, acidification, and death of the fungus.

Pharmacokinetics: Not absorbed from the GI tract, skin, or vagina good for ‘topical’ use

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10
Q

What are the Unwanted effects of Nystatin?

A

None to note however, Allergic reactions very uncommon

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11
Q

What is the Therapeutic Use of Nystatin?

A

Only for candidiasis (thrush)

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12
Q

What are the Griseofulvin?

A

FungiSTATIC and Narrow spectrum

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13
Q

What is the Pharmacokinetics of Griseofulvin?

A
  • Given orally
  • Taken up selectively by newly formed skin, concentrated in keratin
  • t1/2=24h (retained much longer)
  • CYP1A2 inducer Clinically significant drug interactions with warfarin
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14
Q

What are the Unwanted effects of Griseofulvin?

A
  • GI upset
  • Photosensitivity

Caution: Not for use in pregnant women (teratogenic)

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15
Q

What are the unwanted effect of amphotericin B

A

Infusion-related toxicity and nephrotoxicity

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16
Q

What Echinocandins inhibit? e.g. Caspofungin, micafungin, anidulafungin

A

Inhibit synthesis of 1,3-β-D-glucans↓structural integrity=>death
• FungiCIDAL

17
Q

Pharmacokinetics of Echinocandins

A

given i.v.
Don’t penetrate into CSF (cerebrospinal fluid)
No renal clearance
(little effect on [drug] plasma in renal impairment

18
Q

Unwanted effects of Echinocandins

A

Remarkably well tolerated
Phlebitis at injection site (caspofungin)
Histamine-like effects (rapid infusion)

19
Q

Therapeutic Use of Echinocandins

A

Deeply invasive candidiasis

Salvage therapy* for invasive aspergillosis

20
Q

Caspofungin and micofungin are mild inhibitors of CYP3A4

A

↑[drug]plasma tacrolimus

21
Q

rifampicin is inducers of CYP3A4?

A

↓[drug]plasma of caspofungin

22
Q

Azoles (e.g fluconazole, itroconazole, miconazole, voriconazole, posaconazole)

A
  • Inhibit 14-α-sterol demethylase

* FungiSTATIC (broad spectrum)

23
Q

Pharmacokinetics of Azoles

A

Can be given orally or i.v.
Short t1/2 ~6-8h (miconazole., voriconazole)
• Long t1/2 ~30-40h (fluconazole., itroconazole, posaconazole)

24
Q

Unwanted effects of Azoles

A

• Nausea
• Headache
Teratogenic: avoid during pregnancy
Need effective contraception during treatment

25
Q

Therapeutic Use of Azoles

A
  • Candidiasis
  • Seborrheic dermatitis
  • Cryptococcal meningitis (AIDS)
26
Q

Fluconazole, Voriconazole is

A

CYP3A4
CYP2C9
CYP2C19 inhibitor

27
Q

itraconazole, Posaconazole is

A

CYP3A4 inhibitor

28
Q

clotriamzole

A

OTC topical treatment
Superficial fungal infections
Thrush (candidiasis), tinea, fungal keratitis, nappy rash

29
Q

Flucytosine

A

Converted to 5-fluorouracil in fungi
• 5-FU inhibits thymidylate synthetase and DNA synthesis
• Limited spectrum, combined with amphotericin and/or azoles
• Resistance common

30
Q

Pharmacokinetics of Flucytosine

A

Given by i.v. infusion, can also be given orally
• t1/2 ~3-5h
• 90% excreted unchanged by kidney
• Dosage should be reduced in renal impairment

31
Q

Unwanted effects of Flucytosine

A
  • Anaemia,
  • Neutropenia
  • GI disturbances
32
Q

Terbinafine (Lamisil)

A

ergosterol (fungir cell membrane e thaky) synthesis inhibitor

• FungiCIDAL

33
Q

Pharmacokinetics of Terbinafine (Lamisil)

A

Topical or oral
• Well absorbed (↓ bioavailability due to first pass metabolism) • Accumulates in skin, hair and nails
• Metabolised in liver, excreted in urine

34
Q

Unwanted effects of Terbinafine (Lamisil)

A

Low incidence of GI distress, headache or rash
Not recommended in hepatic failure
Systemic therapy avoided during pregnancy

35
Q

Therapeutic Use of Terbinafine (Lamisil)

A

Nail onychomycosis (oral) Tinea (cream or spray)

36
Q

Terbinafine (Lamisil) increase blood plasma of which drugs?

A

Rifampin ↓

Cimetidine ↑