Pharmacology Flashcards
What is the spectrum of activity and mechanism of action of Griseofulvin?
Spectrum: microsporum, trichophyton -> RINGWORM
Mech: inhibits mitosis of fungal cells
What can help increase the oral absorption of Griseofulvin?
give with a meal (griseofulvin with a GREASY meal)
micronized preps, ultramicronized
what are adverse effects associated with griseofulvin?
bone marrow suppression in cats
teratogenic in pregnant animals (cats and horses)
What is the mechanism of action of Amphotericin B?
binds to sterols in fungal cell membranes, fungicidal
may bind to cholesterol in mammals tho
What is the most common adverse effect of amphotericin B? (not if, but when)
Renal injury -> acute azotemia, chronic injury
how can the toxicity of amphotericin B be reduced?
pretreat w fluids and give IV slowly, can do liposomal formulations to help prevent damage to mammalian cells
what drug is amphotericin B synergistic with?
flucytosine -> CNS cryptococcus infection, potential decrease of dose and reduction of toxic effects
which drug should never be given prior to amphotericin B?
any -Azole antifungals -> Amph B cannot bind
What is the mechanism of action of Azole antifungal drugs?
inhibit 14-alpha-demethylase - can’t synthesize ergosterol -> fungistatic
What drugs compose the imidazole group?
Ketoconazole
What drugs compose the Triazole group?
itraconazole
fluconazole
voriconazole
What animal does not absorb ketoconazole?
Horses!!!
what are adverse effects of ketoconazole?
nausea, v/d, hepatotoxicosis, cataracts, fetal death
Steroid synthesis cushings management
How does ketoconazole interact with other drugs?
inhibits CYP450 enzymes ->prevents metabolism of other drugs
inhibit p-glycoprotein efflux pumps -> inc concentration of drugs in CNS, eye, and plasma
Do triazoles affect endocrine function?
NO
What adverse effects are associated with itraconazole?
hepatic: inc. liver enzymes, hepatotoxicosis
GI: anorexia, V+
congestive heart failure
What are the pharmacokinetics of Itraconazole?
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
Where does fluconazole tend to concentrate?
the urine, CSF, aqueous humors
most aspergillus strains are resistant
what are adverse effects associated with fluconazole?
minimal, but may increase hepatic enzymes and prolong recovery from drugs such as ketamine and midazolam
How is voriconazole best absorped?
It has great oral absorption (>100%) and penetrates into CNS and eyes well
DON’T GIVE TO CATS
What toxicity can result from voriconazole administration to cats?
ataxia, paraplegia, mydriasis, hypokalemia, arrhythmias, azotemia, etc…
What is the mechanism of action of Terbinafine (lamisil)
allylamine antifungal that inhibits ergosterol synthesis -> fungicidal
what is the spectrum of activity of terbinafine?
dermatophytes, yeast, dimorphic and filamentous fungi
Are antiviral drugs commonly used in vet med?
NO
What type of drugs are antiherpetic drugs?
nucleoside analogs -> prodrugs
Is clinical use of anti-influenza drugs recommended?
nope
What is the most common adverse effect of cytotoxic drugs?
MYELOSUPPRESSION -> this leads to neutropenia, and sometimes thrombocytopenia
Anemia is unlikely
What are common toxicities produced by specific agents of antineoplastic drugs?
Nausea, phlebitis, cellulitis and necrosis, nephrotoxicity, peripheral neuritis, acute tumor lysis syndrome
What are typical “protocols” of anti-neoplastic drug administration?
Treated with drug combination to attack multiple targets or alternate week therapy to reduce adverse effects
What is the mechanism of action of Cyclophosphamide?
An akylating agent forms a covalent bond with DNA and DNA becomes uncopiable
What are potential adverse effects of Cyclophosphamide?
high doses can cause reversible neurotoxicity in cats
sterile necrotizing hemorrhagic cystitis -> dose in AM and encourage water consumption to help prevent
what is the mechanism of action of Vincristine?
agents bind microtubules and arrest mitosis, cell-cycle, and apoptosis
what are adverse effects associated with Vincristine?
dose dependent leukopenia
peripheral neuropathy
how must vincristine always be administered?
IV ONLY -> vesicant
What is the mechanism of action of Doxorubicin?
topoisomerase inhibitor -> nicks DNA strands
what are adverse effects associated with Doxorubricin?
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
what is the mechanism of action of L-asparaginase
Malignant lymphocytes have a reduced ability to synthesize l-asparagine -> enzyme destroys exogenous supplies
what are adverse effects associated with L-asparaginase?
anaphylaxis (less likely w/ 1st dose)
pancreatitis, dec clotting factors, NO MYELOSUPPRESSION
