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14 Cards in this Set
- Front
- Back
How do venodilators decrease pressure?
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By increasing the lumen size
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What are 2 nitrates used for venodilation?
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1) Nitroglyceride (transcutaneous)
2) Isosorbide (oral) |
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What is the mechanism of action of nitrates?
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Nitrates form NO (nitric oxide) in smooth muscle cells--> relaxation
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What nitrate is a mixed dilator?
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Nitroprusside (IV)
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Why aren't nitrates used commonly in veterinary medicine?
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Tolerance develops quickly-within 24 hours
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What are 2 ways to avoid tolerance to nitrates?
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1) Intermittent use
2) ACE inhibitors (mixed dilator) and hydralazine (arterial dilator) |
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What is the therapeutic use of venodilators (nitrates)?
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Systemic venodilation in heart failure (pulmonary edema)
-Never as the sole drug |
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When is nitroglycerine used and how is it administered?
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Transdermal use on emergency
-Can put on ear or abdomen, ear has less chance of affecting staff |
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When is isosorbide used?
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Chronic use in refractory heart failure
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True or false. Tolerance is an issue with nitroprusside.
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False, not an issue with nitroprusside
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What are 2 uses use of nitroprusside?
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1) Short-term management of fulminant (sudden & severe) heart failure
2) Hypertensive crisis *potent veno and arterial dilator |
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How long do nitroprussides remain in the system after IV injection?
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Effect disappear 5 minutes after stopping drug
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What are 2 side effects of nitroprusside?
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1) *Hypotension
2) Cyanogen toxicity |
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Why do nitrates have to be administered in an IV drip with a special line or a foil cover?
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Sensitive to light, heat and moisture
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