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
