Cardiovascular Meds Flashcards
Cholinergic Drugs:
Atropine
-Atropine (prototype) is the only drug in this category used for cardiovascular purposes
Atropine
- Causes Tachycardia (WANT to speed HR back up!)
- Give for Bradycardia (<60) under standing orders as nurses (standing order = a list of medications that can be given in an emergency setting)
-Muscarinic antagonists selectively block the effects of acetylcholine at the muscarinic receptors.
-Indications:
Bradycardia (in ICU) since atropine increases heart rate, nursing gives per emergency protocols; surgical pretreatment to prevent bradycardia during surgery
-Adverse Effects:
dry mouth, blurred vision and photophobia, elevation of intraocular pressure (avoid in glaucoma), urinary retention; anhidrosis (avoid working in hot weather)
-Interactions:
with antihistamines, phenothiazine antipsychotics, tricyclic antidepressants
- Dosage:
0. 4 mg po; 0.5-1 mg IV infusion (diluted) or IM
Actions of Adrenergic Receptors
Alpha 1:
Arterioles and veins - constriction
Alpha 2:
Nerves only
Beta 1:
Heart and kidney
Heart - increase rate, force of contraction, AV conduction speed
Kidney - release of renin
Beta 2:
Bronchi - dilation, arterioles, heart, lung, skeletal muscle
Epinephrine stimulates alpha 1 and 2, beta 1 and 2, but not _______
dopamine
Norepinephrine stimulates
alpha 1 and 2
Beta 1
Dopamine stimulates
Alpha 1, Beta 1, and dopamine
Alpha Adrenergic Antagonists
(Sympatholytics - blocking the sympathetic system)
ends in -ZOSIN
Prazosin (Minipress)
Prazosin (Minipress)
-MOA:
Inhibits alpha 1 receptors arterioles and veins, causes vasodilation, resulting in decreased BP, decreased CO
-Indications:
Essential Hypertension, BPH, Raynaud’s
-Adverse Effects:
dizziness, Headaches, drowsiness, impotence (alpha 1 blockage inhibits ejaculation), reflex tachycardia, nasal congestion, edema, postural hypotension;
-diuretics and other hypotensive agents potentiate effects. WATCH for 1st dose effect. (GIVE AT BEDTIME)*
-Nursing implications:
IMPOTENCE is a major reason for nonadherence
Terazosin and doxasosin are other alpha adrenergic agonists (8 altogether)
Beta Blockade Therapeutic Effects:
Therapetuic Effects:
- Reduced heart rate
- Reduced peripheral vascular resistance with long term use
- Reduced force of contraction
- Reduced speed of AV conduction (risk for heart blocks)
Beta Blockade Indications:
- Angina
- Hypertension (not as effective as once thought)
- Cardiac dysrhythmias (SA node, sinus tachy and PAC’s)
- MI
- Heart Failure
Beta Blockade Adverse Effects
- Bradycardia
- reduced CO
- precipitation of heart failure
- AV heart block
- rapid withdrawal of drug will cause angina or ventricular dysrhythmias (need to taper withdrawal over several weeks).
Beta Adrenergic Antagonists (Beta Blockers)
ends in -olol
- Propanolol
- Metoprolol
- Atenolol
- Labetol (not on module)
Propanolol
- Take apical pulse and BP before giving
- May mask tachycardic symptoms of hypogylcemia
1st Generation Nonselective beta 1 and 2 adrenergic blocker
-MOA:
blocks adrenergic receptors in the cardiac (beta 1) and lungs (beta 2); renal (beta 1) suppresses renin secretion
-Therapeutic Action:
Antihypertensive, reduces HR, CO used in MI, CAD, HTN, cardiac dysrhythmias.
-Adverse Effects:
Hypotension, bradycardia, bronchoconstriction, may rarely cause depression
-CONTRAINDICATED in: BRONCHITIS & ASTHMA, COPD, DIABETES, & hx of DEPRESSION
-Drug Interactions:
Calcium channel blockers (may cause cardiac suppression, very low heart rate and B/P)).
Usually PO, sometimes IV
Metoprolol (Lopressor, Toprol XL)
Prototype 2nd generation SELECTIVE B1 blocker (cardiac)
-MOA:
Blocks B1 cardiac receptors
Reduces heart rate, force of contraction, AV duration through the node, reduces secretion of renin
-Indications:
1st choice Antihypertensive drug; also approved for angina, MI, heart failure
-Adverse Effects:
bradycardia, reduced cardiac output, AV HEART BLOCK (1ST OR 2ND DEGREE); Also can CAUSE heart failure
-Dosage: IR tablets (immediate released) and SR tablets (sustained release), dosage varies depending on why it is being given; also there is an IV formulation
Atenolol and Labetol
3rd generation beta-blockers
- can dilate blood vessels |
- dosing can be done once a day
- block vascular alpha 1 receptors | IV/PO
Central Acting Alpha 2 Agonists
Clonidine (Catapres)
Clonidine
-MOA:
activates the central alpha 2 receptors in the brainstem and thus reduces sympathetic outflow to blood vessels and the heart.
-Indications:
Treatment of hypertension and in some cases treatment of pain.
-Adverse Effects:
Drowsiness and sedation; xerostomia; constipation, impotence, rebound hypertension in response to abrupt withdrawal; can cause fetal harm; can cause euphoria, hallucinations and can be abused.
- Dosage: Oral, Transdermal (q 7 days)
- Others: Methyldopa and Reserpine (not on module)
ACE (Angiotensin Converting Enzyme) Inhibitor includes:
-pril
- Captopril
- Lisinopril
- Enalapril (Vasotec)
Captopril
-MOA:
Lowers BP by inhibition of ACE; this disrupts conversion of angiotensin I to II in the kidneys; since angiotensin II is a powerful vasoconstrictor, vasodilatation occurs and BP is lowered.
-Indications:
Hypertension, heart failure, MI, B/P med of choice for DM since it slows progression of ESRD
-A/E:
1st dose hypotension, arthralgia, DRY COUGH (increase in bradykinin), ANGIOEDEMA, bradycardia, neutropenia, agranulocytosis, fetal injury, hyperkalemia
-Interactions:
Other antihypertensives enhance hypotensive effect
-Nursing Implications:
Take BP and apical rate before giving; REPORT UNEXPLAINED FEVER; may cause hypoglycemia in DM, check BG
-Give Orally
Lisinopril
USES- hypertension, heart failure, and acute MI
ACTIVE FORM
Enalapril (Vasotec)
USES:
-hypertension, heart failure and asymptomatic LVD
-can reduce the risk of diabetic retinopathy
