Pharm Renal 2

britt611's version from 2017-01-20 04:12

Section 1

Question Answer
What are 3 categories of vasodilators?1. venous 2. Mixed 3. Arterial
what are 2 venous dilators (venodilator)1. nitroglycerine (transcutaneous), 2. Isosorbide (oral)
What are 2 mixed vasodilators1. Nitroprussiates 2. ACE inhibitors
What are 3 arterial vasodilators?1. Hydralazine 2. Calcium-Channel blockers 3. Alpha1- adrenoceptor blockers
Pressure = ?Flow (CO) x Resistance (degree of vasodilation
In Pressure = F x R, what does vasodilators alter?Resistance
Over all, what do venous, arterial and mixed vasodilators doVenous = decreased venous pressure, Arterial = decreases arterial pressure, Mixed = a little of both
How do venodilators decrease venous pressure?by increases the lumen of BV
What are 3 types of Calcium Channel blockers?1. Dihydropyridines (amiodipine), 2. Diltiazem, 3. Verapamil

Section 2

Question Answer
How do Nitrates work?Nitrates form NO in smooth muscle cells causes relaxation
when do tolerance for nitrates develop and how is it avoided? Developed in 24 hours, Avoided by: intermittent use or ACE inhibitors and hydralazine
What is the main use of Arterial dilators?decrease blood pressure (systemic hypertension), Increase CO (heart failure)
What is the Mechanism of action of AmlodipineBlock primarily Ca channels in systemic arteriolar smooth muscle. Leading to arteriolar vasodilation. Almost no effect in the heart
What is the clinical use of amiodipine?mainly to treat hypertension (CATS, dogs), decrease mitral regurgitation in dogs with mitral valve disease (rare)
What is the drug of choice for cats with hypertension?amiodipine
What are the PK in dogs given amlodipine (bioavailability, peak plasma concentration, half life, protein bound?)Oral bioavaliavility = 90%, 6h till peak plasma concentration, 30 half life, 95% protein bound
What are the adverse effects of amlodipinehypotension
what is the mechansim of action of hydralazine?Very potent direct arterial vasodilator via increasing prostacyclin concentrations
What are the clinical uses of hydralazine?primarily used to treat hypertensive crisis (IV) or refractory hypertension, Also decreases mitral regurgitation in dogs with mitral valve disease (refractory failure)
Which drug is used for hypertensive crisis (IV)?hydralazine
Describe the PK in dogs given hydralazine (absorption, metabolsim, plasma concentration)good oral absorption but undergoes first pass hepatic metabolism, 3h till peak plasma concentrations
How quickly does hydralazine effect dogs? (PK) (begins, stable, last)begines 30-60 min, stable for 8-10 hours, last 21 hr. Dose must be TITRATED
What are the adverse effects of hydralazine?hypotension, anorexia/vomiting, reflex tachycardia
Which drug is NOT used in cats with heart disease?prazosin
What type of dilator is prazosin?Arteriolar and venodilator- rarely used in dogs- DO NOT use in cats
What are the adverse effects of prazosinreflex tachycardia
What are the clinical uses of prazosinArterial hypertension (refractory), Urethral relaxation (not #1 drug to use)
What type of dilators are ACE inhibitorsarteriolar and venodilators (Mixed vasodilators)
What are ACE inhibitors commonly used for?Prolongs survival in heart failure and renal failure - has a neuroendocrine and local effects
What drug is know to prolong survival time in heart/renal failure?ACE inhibitors
Describe the progression of renal failureincrease angiotensin II lead to: increased NF-kb, TGF-b, mesangial hypertrophy, glomerular pressure, this leads to: glomerular sclerosis, fibrosis and/or inflammation
Why are ACE inhibitors called special vasodilatorsthey are not very potent and have a weak hemodynamic effect
What is the Mechanism of Action of ACE inhibitorsACE inhibition systemic and local- stops Angiotensin 1 converting to angiotensin 2
What are the 2 main examples of ACE inhibitors?Enalapril and Benazepril (other: ramipril, lisinopril and captopril)
What are the clinical uses of ACE inhibitors?1. systemic hypertension ( first drug - nephroprotection from proteinuria and renal failure) 2. heart failure (vasodilator of choice, neuroendocrine modulation) 3. renal failure (increase survival time and proteinuria)
What is the vasodilator of choice for heart failure?ACE inhibitors
What are the adverse effects of ACE inhibitorshypotension (rare), anorexia/vomiting, renal failure (patients that are volume depleted)

Section 3

Question Answer
What is hypotonic urethra?sphicter incompetence leading to urinary incompitance
What patients do we see sphincter incompetence?adult spayed female dogs
What are 2 drugs that are used to treat sphincter incompetence?a-adrenergic agonists and reproductive hormones
What are 2 examples of a-adrenergic agonists that increase urethral tone?1. phenylopropanolamine (PPA) 2. phenylephrine
What are the effects of PPAincreasing urethral tone via direct stimulation of receptors (can be used in males and females
what are the effects of phenylephrine?increasing urethral tone- less predictable effect
What are the adverse effects of a-adrenergic agonists?anorexia, weight loss, hyperexcitability, tachycardia, hypertension
What are 2 reproductive hormones that increase urethral tone?1. diethylstillbestrol 2. testosterone
What is the function of diethylstilbestrol?increasing urethral tone via sensitization and up regulation of a-receptors - can be used in females
What are the side effects of diethylstilbestrol?alopecia, signs of estrus, bone marrow suppression
What is the function of testosterone?increasing urethral tone in males- IM only - rarely used due to side effects
What is the main side effects of testosterone?increase aggression
define hypertonic urethra?excessive muscle tone
how do you treat hypertonic urethra?A-adrenergic antagonist (phenoxybenzamine) and diazepam
What drugs do you use to treat hypertonic urethra by decreasing smooth muscle tonea-adenergic antagonist
what drugs do you use to treat hypertonic urethra by decreasing striated muscle tone?diazepam
How does phenoxybenzamine work?decreases smooth muscle tone by irreversibly inactivating a-receptors - less predictable in cats
why is phenoxybenzamine less predictable in cats?striated muscles are less predominante in the feline urethra
What are the side effects of phenoxybenxzamine?hypotension, reflex tachycardia, GI upset
How does diazepam work?treatment for hypertonic urethra by decreases striated muscle tone- short acting so should be given 15-30 minutes before micturition
what doe higher doses of diazepam lead to?sedation
What are the side effects of diazepam?sedation, weakness, paradoxical excitement, hepatoxicity (cats)
What are causes of hypotonic bladder?neurologic disease, overdistension of the bladder
What drug is used to treat hypotonic bladdercholinergic agents- bethanechol
What is bethanechol used for?treatment of hypotonic bladder- unreliable, full effect in 1-2 days, may increase urethral tone (start a-blocker first)
What should you start first to prevent increase in urethral tone by giving bethanechol?start a-blocker first
Define hypotonic bladdercant contract bladder
what are the side effects of bethanechol?salivation, defication, abdominal cramps, vomiting, diarrhea