Antifungal Drugs

Question 1

Griseofulvin produced by

Answer 1

Penicillium griseofulvum

Question 2

Griseofulvin sectrum of action

Answer 2

-dermatophtyosis (microsporum, epidermophyton, trichophyton)

Question 3

Griseofulvin mechanism of action

Answer 3

• primarily active on growing cells

- binds to intracellular microtubules inhibiting mitosis, synthesis of NA, chitin synthese

Question 4

Griseofulvin elimination

Answer 4

• excreted i sweat

- reaches the skin in 4-8 hours

Question 5

Griseofulvin absorption

Answer 5

• increased absorption with fatty meals

Question 6

Griseofulvin metabolism

Answer 6

• Oxidized by hepatic microsomes enzymes

- excreted in the urine

Question 7

Griseofulvin drug interactions

Answer 7

-phenobarbital decreases absorption

Question 8

Griseofulvin adverse effects

Answer 8

• tastes bad

- bone marrow suppression

Question 9

Griseofulvin teratogenicity

Answer 9

• malformations of the brain
• skeletal malformations
• cyclopia and anophthalmia

Question 10

Amphotericin B spectrum

Answer 10

Cryptococcosis, blastomycosis, histoplasmosis, coccidomycosis

Question 11

Amphotericin B binding, half life, metabolism

Answer 11

• high protein binding
• 24 hours
• 10% excreted in the urine

Question 12

Amphotericin B adverse effects

Answer 12

• Thrombophlebitis
• nephrotoxicity
• hypokalemia
• resistance develops over time

Question 13

Ketoconazole Solubility

Answer 13

• insoluble in water

- soluble in acidic environments

Question 14

Ketoconazole inhibits

Answer 14

Lanosterol 14-demethylase

Question 15

Ketoconazole spectrum

Answer 15

• stsyemic infections
• dermatophytosis
• malassezia

Question 16

Ketoconazole peaks, metabolism, half life

Answer 16

2 hours, liver, 2 hours

Question 17

Ketoconazole therapeutic effect and interactions

Answer 17

• 5-10 days

- Drugs with cytochrome P450

Question 18

Ketoconazole adverse effects

Answer 18

• not for cats
• GI upset
• hepatoxociity
• teratogenic

Question 19

Itraconazole affinity

Answer 19

-increased affinity for fungal enzyme, 5-100x more active than ketoconazole

Question 20

Itraconazole half life

Answer 20

Dogs: 8-12 hours
Cats: 40-120 hours

Question 21

Itraconazole adverse effects

Answer 21

• drug interactions
• GI upset
• liver toxicity
• vasculitis at high does

Question 22

Fluconazole excretion and perfusion

Answer 22

Reaches the brain
No liver metabolism
Urinary excretion

Question 23

Terbinafine mechanism

Answer 23

Inhibition of squareness epoxidase
Inhibition of ergosterol synthesis
No p450 interference

Question 24

Terbinafine spectrum

Answer 24

Dermatophytosis

Malassezia