Pharmacology Flashcards
What is the mechanism of action of furosemide and where does it work?
Impairs the activity of the NA+-K+-2Cl- cotransporter in the thick ascending loop of Henle
What is the mechanism of action of cisplatin?
Platinum drug - causes DNA cross linking
What is the mechanism of action of azathioprine?
Antagonizes purine metabolism by causing breaks in DNA and RNA secondary to incorporation into nucleic acids and termination of the replication process
What is the mechanism of action of methimazole?
Inhibits thyroid peroxidase and interferes with iodine incorporation into tyrosyl residues of thyroglobulin, thereby inhibiting thyroid hormone synthesis
What is the mechanism of action of leflunomide?
Pyrimidine synthesis inhibitor that inhibits autoimmune T-cell proliferation and autoantibody production by B cells
How much more potent is dexamethasone than prednisone?
7x
What is the mechanism of action of firocoxib?
COX-2 inhibitor
What is the mechanism of action of enrofloxacin?
DNA gyrase (topoisomerase II) inhibitor
Which chemotherapy drugs are substrates for glycoprotein ABCB1?
Doxorubicin
Vincristine
Mitoxantrone
What is the mechanism of action of digoxin?
Increases the availability of Ca++ to myocardial fibers and Inhibit Na3/K2/ATPase pump -> Increase NaCaX
What serum electrolyte abnormality would exacerbate digoxin toxicity?
Hypokalemia
Mechanism of action of phenylpropanolamine
Sympathomimetic- alpha agonist at urethral sphincter
It indirectly stimulates both α- and, to a lesser degree, β-adrenergic receptors of smooth muscle by causing the release of norepinephrine and inhibition of reuptake at the synaptic junction. Phenylpropanolamine’s α-adrenergic stimulation increases urethral sphincter tone and produces closure of the bladder neck.
Which drug creates clinically significant hypothyroidism?
TMS
Phenobarbital (can lower T4 but should not cause clinical hypothyroidism)
What is the mechanism of action of TMS?
Inhibits enzymes in the folic acid pathway, inhibiting bacterial thymidine synthesis
Which antibiotics penetrate the prostate?
TMS
Chloramphenicol
Enrofloxacin
What is the mechanism of action of doxycycline?
Reversibly binds to the 30S ribosomal subunits of susceptible organisms
What is the mechanism of action of cyclosporine?
It binds and forms a complex with cyclophilin, which inhibits calcineurin/NFAT (nuclear factor of activated T cells), which decreases T-cell inflammatory cytokine production (IL-2).
Which reaction is the main phase II reaction for drugs? (choices: glucuronidation, hydroxylation, oxidation, sulfonation)
Glucuronidation
Why is liposomal amphothericin B less nephrotoxic than deoxycholate amphothericin B?
The liposomal form exhibits less interaction with cholesterol in the kidney
Most common side effects of Imatinib?
GI
What is the mechanism behind the acute side effects of doxorubicin?
An immediate histamine-mediated hypersensitivity reaction characterized by urticaria, facial swelling, vomiting, arrhythmias, and/or hypotension (particularly in dogs)
Risk is lowered by administering as a slow infusion (over 15-30 minutes)
What is the mechanism of action of clopidogrel?
Platelet aggregation inhibitor
It binds selectively to the platelet surface adenosine diphosphate (ADP) receptor, P2Y12, and irreversibly alters the ADP receptor for the lifespan of the platelet. This receptor alteration reduces activation of the glycoprotein GPIIb/IIIa complex, which inhibits platelet activation and subsequent inhibition of primary and secondary platelet aggregation.
What is the mechanism of action of diazoxide?
Inhibits closure of ATP-dependent K+ channels in the beta cells of the pancreas (inhibiting depolarization and thus preventing release of insulin)
What is the mechanism of action of cisapride?
5HT4 agonist
What is the mechanism of action of ondansetron?
5HT3 antagonist
What is the mechanism of action of gabapentin?
Inhibition of voltage-gated Ca++ channels
What is the mechanism of slentrol (dirlotapide)?
Causes accumulation of lipids in enterocytes
What is the location of nephrotoxicity for gentamicin?
Proximal tubule
What is the mechanism of action of aspirin?
It inhibits cyclooxygenase (COX-1, prostaglandin synthetase), thereby reducing prostaglandin and thromboxane (TXA2) synthesis.
What drug decreases CSF production?
Omeprazole
What do you need to determine drug dose in an animal? (Choices: volume of distribution, Cmax, Tmax, plasma drug concentration)
Volume of distribution
Which drug can be used as a promotability agent and has anticholinesterase properties?
Neostigmine
What antibiotic acts on topoisomerases II (DNA gyrase)?
Enrofloxacin
What is the mechanism of action of Lidocaine?
Na channel blocker Class IB
How does heparin affect clotting cascade?
Increases potency of antithrombin III (AT)
What’s the mechanism of action of sildenafil?
PDE5 inhibitor
Which antibiotic concentrates in the urine/bladder?
Amoxicillin/Clavamox
Chloramphenicol
Fluoroquinolones
What is the mechanism of action of pimobendan?
PDE-III inhibitior, inodilator, Ca sensitizer
What chemo drug causes arrest during metaphase?
Vinblastine (VBL)
What chemo drug causes mast cell degranulation?
Doxorubicin
What is the mechanism of action of amoxicillin?
Inhibit cell wall synthesis; act by inhibiting mucopeptide synthesis in the cell wall
What makes glargine a long acting insulin?
Crystals in the SQ (micro precipitants in neutral pH of SC tissue)
Most common adverse effect with oclacitinib (aka Apoquel)?
Diarrhea (gastrointestinal upsets, such as decreased appetite, vomiting and diarrhea)
What is the mechanism of action of cobalamin?
Cobalt-containing water-soluble vitamin, serves as an important cofactor for many enzymatic reactions
Binds to intrinsic factor in the G.I. for absorption
Required for folate utilization
What is the mechanism of action of fludricortisone?
Potent corticosteroid that possesses both glucocorticoid and mineralocorticoid activity (only used for mineralcorticoid activity)
Acts on renal distal tubule where it increases the absorption of sodium and enhance potassium and hydrogen ion excretion.
Which of the following is most susceptible to first pass metabolism?
Rectal - almost identical to oral
What is the mechanism of action of Sulfonamide?
Prevent folic acid synthesis
What are the side effects of desmopressin?
Hypersensitivity reactions are possible
Hypernatremia with overdose
