Pharm - Autonomic Drugs (Sympathomimetic Specifics) Flashcards
Pg. 249-251 in First Aid 2014 Sections include: -Norepinephrine vs. isoproterenol -Sympatholytics (alpha2-agonists) -Alpha-blockers -Beta-blockers
Compare/Contrast the use and effects of Norepinephrine and Isoproterenol.
NOREPINEPHRINE causes an increase in systolic and diastolic pressures as a result of alpha 1 -mediated vasoconstriction => increased mean arterial pressure => bradycardia. However, ISOPROTERENOL (no longer commonly used) has little alpha effect but causes Beta2-mediated vasodilation, resulting in decreased mean arterial pressure and increased heart rate through Beta 1 and reflex activity
Draw graphs showing diastolic, mean, and systolic blood pressures for Norepinephrine versus Isoproterenol.
See p. 249 in First Aid 2014 for visuals
Draw graphs showing heart rate for Norepinephrine versus Isoproterenol.
See p. 249 in First Aid 2014 for visuals
What is another name for Sympatholytics? Give 2 examples of such drugs.
Sympatholytics (Alpha2-agonists); (1) Clonidine (2) Alpha-Methyldopa
What are 4 clinical applications for Clonidine? What is an important consideration for one of these applications?
(1) Hypertensive urgency (limited situations); does not decrease renal blood flow, (2) ADHD, (3) severe pain, and a (4) variety of off-label indications (e.g., ethanol and opioid withdrawal)
What are 5 toxicities associated with the use of Clonidine?
(1) CNS depression, (2) Bradycardia, (3) Hypotension, (4) Respiratory depression, and (5) Small pupil size
What is a major clinical application of alpha-methyldopa? What is an important consideration for this application?
Hypertension in pregnancy; Safe in pregnancy
What are 2 toxicities associated with the use of alpha-methyldopa?
(1) Direct Coombs positive hemolytic anemia (2) SLE-like syndrome
What are 2 examples of nonselective alpha-blockers? Which is reversible versus irreversible?
(1) Phenoxybenzamine (irreversible) (2) Phentolamine (reversible)
What is the clinical application for Phenoxybenzamine?
Pheochromocytoma (used preoperatively) to prevent catecholamine (hypertensive) crisis
What are 2 toxicities associated with Phenoxybenzamine?
(1) Orthostatic hypertension (2) Reflex tachycardia
What is the clinical application for Phentolamine?
Give to patients on MAO inhibitors who eat tyramine-containing foods
What are 4 examples of alpha 1 selective alpha blockers? What do their names all have in common?
(1) Prazosin (2) Terazosin (3) Doxazosin (4) Tamsulosin; (-osin ending)
What are 3 clinical applications for Prazosin, terazosin, doxazosin, and tamsulosin (i.e., alpha 1 selective alpha blockers)? Where applicable, specify which drugs are used in each context.
(1) Urinary symptoms of BPH; (2) PTSD (Prazosin); (3) Hypertension (except Tamsulosin)
What are 3 toxicities associated with Prazosin, terazosin, doxazosin, and tamsulosin (i.e., alpha 1 selective alpha blockers)?
(1) 1st dose orthostatic hypotension (2) Dizziness (3) Headache
What is an example of an alpha 2 selective alpha-blocker?
Mirtazapine
What is the clinical application for Mirtazapine?
Depression
What are 3 toxicities associated with Mirtazapine?
(1) Sedation (2) Increased serum cholesterol (3) Increased appetite
Explain the effects of an alpha-blocker (e.g., phentolamine) on blood pressure responses to epinephrine versus phenlephrine.
The epinephrine response exhibits reversal of the mean blood pressure change, from a net increase (the alpha response) to a net decrease (the Beta 2 response). The response to phenylephrine is suppressed but not reversed because phenylephrine is “pure” alpha-agonist without beta action.
Draw the effects of epinephrine versus phenlephrine before and after alpha blockade.
See p. 250 in First Aid 2014 for visual
Name 10 beta-blockers.
(1) Metoprolol (2) Acebutolol (3) Betaxolol (4) Carvedilol (5) Esmolol (6) Atenolol (7) Nadolol (8) Timolol (9) Pindolol (10) Labetalol.
What are 5 clinical applications for beta-blockers? Where applicable, give the specific beta-blocker(s) used for a given application.
(1) Angina pectoris (2) MI (3) SVT (metoprolol, esmolol) (3) Hypertension (4) CHF (5) Glaucoma (timolol)
What effects do beta blockers have in the context of angina pectoris?
Decrease heart rate and contractility, resulting in decreased O2 consumption
What effects do beta blockers have in the context of MI? List 3 specific beta blockers for this application.
Beta-blockers (metoprolol, carvedilol, and bisoprolol) decrease mortality
Again, what 2 beta blockers are used in the context of SVT? What effects do they have? To what drug class do they belong on the basis of such effects?
SVT (metoprolol, esmolol); Decrease AV conduction velocity (class II antiarrhythmic)
What effects do beta blockers have in the context of hypertension, and why?
Decrease cardiac output, Decrease renin secretion (due to Beta 1-receptor blockade on JGA cells)
What effect do beta blockers have in the context of CHF?
Slows progression of chronic failure
Again, what beta blocker is used in the context of Glaucoma? What effect does it have?
Glaucoma (timolol); Decrease secretion of aqueous humor
What are 5 major toxicities associated with beta-blockers? Where applicable, give the specific beta-blocker to which a toxicity pertains.
(1) Impotence (2) Cardiovascular adverse effects (bradycardia, AV blocks, CHF) (3) CNS adverse effects (seizures, sedation, sleep alterations), (4) Dyslipidemia (metoprolol), and (5) Asthmatics/COPDers (may cause exacerbation)
In what patient population are beta-blockers avoided, and why?
Avoid in cocaine users due to risk of unopposed alpha-adrenergic receptor agonist activity
What is a consideration of beta-blocker use in diabetics? Are beta-blockers contraindicated in diabetics?
Despite theoretical concern of masking hypoglycemia in diabetics, benefits likely outweigh risks; not contraindicated
Name 5 Beta 1 -selective antagonists.
Beta 1-selective antagonists (Beta 1 > Beta 2) - (1) Acebutolol (partial agonist) (2) Atenolol (3) Betaxolol (4) Esmolol (5) Metoprolol; Think: “Selective antagonists mostly go from A to M (Beta 1 with 1st half of alphabet)
Name 4 nonselective Beta antagonists.
Nonselective antagonists (Beta 1 = Beta) - (1) Nadolol (2) Pindolol (partial agonist) (3) Propanolol (4) Timolol; Think: “Nonselective antagonists mostly go from N to Z (Beta 2 with 2nd half of alphabet)”
Name 2 nonselective alpha and beta antagonists.
Nonselective alpha and beta antagonists - (1) Carvedilol (2) Labetalol; Think: “Nonselectives alpha and beta antagonists have modified suffixes (instead of ‘-olol’)”
On what receptors does Nebivolol, and how? What effect does this have?
Nebivolol combines cardiac-selective beta1-adrenergic blockage with stimulation of beta3-receptors, which activate nitric oxide synthase in the vasculature
