Pharmacology

Question 1

What is the spectrum of activity and mechanism of action of Griseofulvin?

Answer 1

Spectrum: microsporum, trichophyton -> RINGWORM
Mech: inhibits mitosis of fungal cells

Question 2

What can help increase the oral absorption of Griseofulvin?

Answer 2

give with a meal (griseofulvin with a GREASY meal)
micronized preps, ultramicronized

Question 3

what are adverse effects associated with griseofulvin?

Answer 3

bone marrow suppression in cats
teratogenic in pregnant animals (cats and horses)

Question 4

What is the mechanism of action of Amphotericin B?

Answer 4

binds to sterols in fungal cell membranes, fungicidal
may bind to cholesterol in mammals tho

Question 5

What is the most common adverse effect of amphotericin B? (not if, but when)

Answer 5

Renal injury -> acute azotemia, chronic injury

Question 6

how can the toxicity of amphotericin B be reduced?

Answer 6

pretreat w fluids and give IV slowly, can do liposomal formulations to help prevent damage to mammalian cells

Question 7

what drug is amphotericin B synergistic with?

Answer 7

flucytosine -> CNS cryptococcus infection, potential decrease of dose and reduction of toxic effects

Question 8

which drug should never be given prior to amphotericin B?

Answer 8

any -Azole antifungals -> Amph B cannot bind

Question 9

What is the mechanism of action of Azole antifungal drugs?

Answer 9

inhibit 14-alpha-demethylase - can’t synthesize ergosterol -> fungistatic

Question 10

What drugs compose the imidazole group?

Answer 10

Ketoconazole

Question 11

What drugs compose the Triazole group?

Answer 11

itraconazole
fluconazole
voriconazole

Question 12

What animal does not absorb ketoconazole?

Answer 12

Horses!!!

Question 13

what are adverse effects of ketoconazole?

Answer 13

nausea, v/d, hepatotoxicosis, cataracts, fetal death
Steroid synthesis cushings management

Question 14

How does ketoconazole interact with other drugs?

Answer 14

inhibits CYP450 enzymes ->prevents metabolism of other drugs
inhibit p-glycoprotein efflux pumps -> inc concentration of drugs in CNS, eye, and plasma

Question 15

Do triazoles affect endocrine function?

Answer 15

NO

Question 16

What adverse effects are associated with itraconazole?

Answer 16

hepatic: inc. liver enzymes, hepatotoxicosis
GI: anorexia, V+
congestive heart failure

Question 17

What are the pharmacokinetics of Itraconazole?

Answer 17

HIGHLY lipophilic -> concentrates in tissues for a very long time, likes to bind proteins
Absorption can be increased by food in cats and dogs, but decreases in horses

Question 18

Where does fluconazole tend to concentrate?

Answer 18

the urine, CSF, aqueous humors

most aspergillus strains are resistant

Question 19

what are adverse effects associated with fluconazole?

Answer 19

minimal, but may increase hepatic enzymes and prolong recovery from drugs such as ketamine and midazolam

Question 20

How is voriconazole best absorped?

Answer 20

It has great oral absorption (>100%) and penetrates into CNS and eyes well

DON’T GIVE TO CATS

Question 21

What toxicity can result from voriconazole administration to cats?

Answer 21

ataxia, paraplegia, mydriasis, hypokalemia, arrhythmias, azotemia, etc…

Question 22

What is the mechanism of action of Terbinafine (lamisil)

Answer 22

allylamine antifungal that inhibits ergosterol synthesis -> fungicidal

Question 23

what is the spectrum of activity of terbinafine?

Answer 23

dermatophytes, yeast, dimorphic and filamentous fungi

Question 24

Are antiviral drugs commonly used in vet med?

Answer 24

NO

Question 25

What type of drugs are antiherpetic drugs?

Answer 25

nucleoside analogs -> prodrugs

Question 26

Is clinical use of anti-influenza drugs recommended?

Answer 26

nope

Question 27

What is the most common adverse effect of cytotoxic drugs?

Answer 27

MYELOSUPPRESSION -> this leads to neutropenia, and sometimes thrombocytopenia

Anemia is unlikely

Question 28

What are common toxicities produced by specific agents of antineoplastic drugs?

Answer 28

Nausea, phlebitis, cellulitis and necrosis, nephrotoxicity, peripheral neuritis, acute tumor lysis syndrome

Question 29

What are typical “protocols” of anti-neoplastic drug administration?

Answer 29

Treated with drug combination to attack multiple targets or alternate week therapy to reduce adverse effects

Question 30

What is the mechanism of action of Cyclophosphamide?

Answer 30

An akylating agent forms a covalent bond with DNA and DNA becomes uncopiable

Question 31

What are potential adverse effects of Cyclophosphamide?

Answer 31

high doses can cause reversible neurotoxicity in cats

sterile necrotizing hemorrhagic cystitis -> dose in AM and encourage water consumption to help prevent

Question 32

what is the mechanism of action of Vincristine?

Answer 32

agents bind microtubules and arrest mitosis, cell-cycle, and apoptosis

Question 33

what are adverse effects associated with Vincristine?

Answer 33

dose dependent leukopenia
peripheral neuropathy

Question 34

how must vincristine always be administered?

Answer 34

IV ONLY -> vesicant

Question 35

What is the mechanism of action of Doxorubicin?

Answer 35

topoisomerase inhibitor -> nicks DNA strands

Question 36

what are adverse effects associated with Doxorubricin?

Answer 36

acute -> ekg changes, brief cardiac arrest

short term -> weight lostt, anorexia, v/d, neutropenia, bone marrow hypoplasia, poikilocytosis in cats, lymphoid atrophy

DOSE DEPENDENT CARDIAC TOXICITY

Question 37

what is the mechanism of action of L-asparaginase

Answer 37

Malignant lymphocytes have a reduced ability to synthesize l-asparagine -> enzyme destroys exogenous supplies

Question 38

what are adverse effects associated with L-asparaginase?

Answer 38

anaphylaxis (less likely w/ 1st dose)
pancreatitis, dec clotting factors, NO MYELOSUPPRESSION