Drug Quiz #3: Mechanism of Action Flashcards
Indigotindisulfonate Sodium (Indigo Carmine)
A biologically inert blue dye. After intravenous injection, iT is excreted by the kidney through tubular secretion and, with its deep blue color, it enhances visualization of the ureteral orifices. Because of this, it’s is used to identify ureteral patency in urologic and gynecologic procedures
Milrinone (Primacor)
A selective phosphodiesterase inhibitor in cardiac and vascular tissue, resulting in vasodilation and inotropic effects with little chronotropic activity.
Methylene Blue (ProvayBlue)
In the treatment of vasoplegia syndrome, methylene blue may be able to restore vascular tone by a direct inhibitory effect on endothelial nitric oxide synthase (eNOS), and probably inducible NOS (iNOS), by oxidation of enzyme-bound ferrous iron. In cyanide toxicity, methemoglobin combines with cyanide to form cyanomethemoglobin preventing the interference of cyanide with the cytochrome system.
Misoprostol (Cytotec)
A synthetic prostaglandin E1 analog that replaces the protective prostaglandins consumed with prostaglandin-inhibiting therapies (eg, NSAIDs); has been shown to induce uterine contractions
Isosulfan Blue (Lymphazurin)
Isosulfan blue binds to serum proteins and is then drained by the regional lymphatic system; blue coloration imparted by the dye permits delineation of the vessels against the surrounding tissue.
Rocuronium (Zemuron, Esmeron)
Blocks acetylcholine from binding to receptors on motor endplate inhibiting depolarization
Nitroglycerin (Nitrostat, Nitro-Bid, Nitro-Dur, Nitro-Time, Nitrolingual, Nitromist, Gonitro, Minitran)
Forms the free radical nitric oxide. In smooth muscle, nitric oxide activates guanylate cyclase which increases guanosine 3’5’ monophosphate (cGMP) leading to dephosphorylation of myosin light chains and smooth muscle relaxation. Produces a vasodilator effect on the peripheral veins and arteries with more prominent effects on the veins.`
Vasopressin (Vasostrict)
Stimulates a family of arginine vasopressin (AVP) receptors, oxytocin receptors, and purinergic receptors (Russell 2011). Vasopressin, at therapeutic doses used for vasodilatory shock, stimulates the AVPR1a (or V1) receptor and increases systemic vascular resistance and mean arterial blood pressure; in response to these effects, a decrease in heart rate and cardiac output may be seen. When the AVPR2 (or V2) receptor is stimulated, cyclic adenosine monophosphate (cAMP) increases which in turn increases water permeability at the renal tubule resulting in decreased urine volume and increased osmolality. Vasopressin, at pressor doses, also causes smooth muscle contraction in the GI tract by stimulating muscular V1 receptors and release of prolactin and ACTH via AVPR1b (or V3) receptors
Eptifibatide (Integrillin)
A cyclic heptapeptide which blocks the platelet glycoprotein IIb/IIIa receptor, the binding site for fibrinogen, von Willebrand factor, and other ligands. Inhibition of binding at this final common receptor reversibly blocks platelet aggregation and prevents thrombosis
Bivalirudin (Angiomax)
A specific and reversible direct thrombin inhibitor; it binds to the catalytic and anionic exosite of both circulating and clot-bound thrombin. Catalytic binding site occupation functionally inhibits coagulant effects by preventing thrombin-mediated cleavage of fibrinogen to fibrin monomers, and activation of factors V, VIII, and XIII. Shows linear dose- and concentration-dependent prolongation of ACT, aPTT, PT, and TT.
Factor VIIa (Recombinant) (Novoseven RT, Sevenfact)
Recombinant factor VIIa, a vitamin K-dependent glycoprotein, promotes hemostasis by activating the extrinsic pathway of the coagulation cascade. It replaces deficient activated coagulation factor VII, which complexes with tissue factor and may activate coagulation factor X to Xa and factor IX to IXa. When complexed with other factors, coagulation factor Xa converts prothrombin to thrombin, a key step in the formation of a fibrin-platelet hemostatic plug.
