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9 Cards in this Set
- Front
- Back
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Nitrates: MOA
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-release of NO and/or nitrothiols
-activation of cytosolic guanylate cyclase to form cGMP -cGMP activation of protein kinase phosphorylates proteins -decrease in myosin light chain kinase causes dephosphorylation of myosin, relaxes vessels |
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Nitrates: Physiological Responses
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-venodilation, reduced preload
-dilation of coronary vessels -decreased TPR, caridac output -reduced O2 demand -decreased platelet adhesion -reflex tachycardia -balance 02 supply w/demand |
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Nitrates: Tolerance
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-undergo bio-activation w/sulfhydryl groups:
-no cross tolerance w/NO -sulfhydryl-reducing agents reverse -N-Acetylcysteine reverses -activation of counter-reg mechanisms (Ang II, etc) -free radical hypothesis: -interferes w/endothelium |
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Nitrates: Side Effects
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-Headache
-Postural hypotension -Reflex tachycardia -Overdose: elevated methemoglobin -Oral agents: nausea -Patches: skin reactions |
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BiDil
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Isosorbide Dinitrate + Hydralazine:
-fixed combo: 20 mg Iso, 37.5 mg Hydralazine |
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Sildenafil: MOA
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-inhibits cGMP - PDE5 (PDE1-PDE11)
-NO released into corpus cavernosum to allow blood inflow and erection -NO activates guanylate cyclase to make cGMP |
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Sildenafil: Side Effects
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-Headache
-Flushing -Dyspepsia -Priaprism -Visual disturbances (PDE6) -Potentiates actions of nitrates and NO donors; may induce severe ischemia |
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Tadalafil
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Cialis
-FDA 2002 -24 to 36 hr duration -PDE5 selective |
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Vardenafil
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Levitra
-Aug 2003 -Faster onset -PDE5, some PDE6 |
