NCLEX Cardiac Drugs Part 2

We continue our series on Cardiac Drugs – you can find part one of the series here – http://www.nclexreviewonline.com/cardiac-drugs-for-nclex-part-1/

Centrally Acting α₂ Agonists

Expected Action:

Decreased sympathetic outflow in CNS – > bradycardia, Decreased CO, vasodilation, Decreased BP

Example: clonidine (Catapres) –

Others: guanfacine (Tenex), methyldopa (Aldomet)

Therapeutic Uses:

Hypertension, Severe cancer pain (epidural), Investigational: Migraine, flushing from menopause, withdrawal management

Adverse Effects:

Dry mouth (usually resolves in 2-4 weeks)
Drowsiness & sedation
Rebound hypertension

Contraindications/Precautions:

Pregnancy (C)

Interactions:

Antihypertensives: Additive hypotensive effect
Prazosin, MAOIs, TCAs: Counteract effects of clonidine.
CNS Depressants: Additive CNS depressant effect

Education:

Apply patch to hairless skin on torso or upper arm

β-Adrenergic Blockers

Expected Action:

β₁-adrenergic blockade Decreased HR, Decreased contractility, Decreased AV conduction

Examples: Cardioselective: metoprolol (Lopressor), Nonselective: propanolol (Inderal) – Others: Cardioselective: atenolol, Nonselective: nadolol (Corgard)

Therapeutic Uses:

Hypertension, Dysrhythmias (block SA/AV cond.), Angina/MI (Decreased O₂ demand – increased diastole time \ increased perfusion – Decreased BP leads to Decreased O₂), Heart failure (mechanism unknown, probably related to above), Hyperthyroidism, migraines, stage fright, pheochromocytoma, glaucoma

Adverse Effects:

β_{1 –}Bradycardia, Decreased CO, AV block, Orthostatic hypotension, Rebound myocardium excitation (d/c over 1-2 weeks)

β_{2 –}Bronchoconstriction, Glycogenolysis inhibited

Contraindications/Precautions:

CI: AV block, sinus bradycardia

Nonselectives are CI ĉ asthma, bronchospasms, heart failure

Interactions:

β₁: calcium-channel blockers verapamil (Calan) and diltiazem (Cardizem) intensify effects of β-blockers.

β₂: Insulin – prevents glycogenolysis

Angiotensin-Converting Enzyme (ACE) Inhibitors

Expected Action:

Block production of angiotensin II leads to arteriole vasodilation, excretion of Na⁺ and H₂O, retention of K⁺, and possible pathological changes to vessels and heart

Proto: captopril (Capoten) — Others: enalapril (Vasotec), fosinopril (Monopril), lisinopril (Prinivil), ramipril (Altace

Therapeutic Uses:

Heart failure, Hypertension, MI (Decreased risk of HF and mortality), Peripheral neuropathy, Ramipril can prevent MI, stroke, or death in high-risk patients

Adverse Effects:

Hyperkalemia, Cough, Neutropenia, Angioedema (swelling in tongue/oropharynx) – treat with epinephrine, First-dose orthostatic hypotension, Rash & dysgeusia

Contraindications/Precautions:

Pregnancy (D)
CI: bilateral renal stenosis, history of angioedema

Interactions:

Diuretics leads to 1^st-dose hypotension

Lithium leads to increased [Lithium]

Antihypertensives leads to Additive effects

NSAIDs Decreased antihypertensive eff

K⁺ supplements/K⁺ sparing diuretics leads to hyperkalemia

Education:

Captopril 1 hr ac / others ĉ or ŝ food

Should see increased renal function evidenced by Decreased proteinuria

Angiotensin Receptor Blockers (ARBs)

Expected Action:

Blocks action of angiotensin leads to arteriole vasodilation, excretion of Na⁺ & H₂O, retention of K⁺

Δ ACE and ARB is that cough and hyperkalemia are not side effects of ARB.

Proto: Losartan (Cozaar) — Others: valsartan (Diovan), irbesartan (Avapro), candesartan (Atacand), olmesartan (Benicar)

Therapeutic Uses:

Decreased hypertension (all)
Stroke prevention (losartan)
Mgt of heart failure / mortality prevention after MI (valsartan)
Delay progression of diabetic neuropathy (irbesartan, losartan)

Adverse Effects:

Angioedema
Fetal injury

Contraindications/Precautions:

Pregnancy (D)
CI: Renal stenosis
Caution ĉ Hx of angioedema

Education:

ARBs can be taken with or without food
Should see increased renal function evidenced by Decreased proteinuria

Calcium Channel Blockers

Expected Action:

Nifedipine: V vascular Ca²⁺channels leads to vasodilation peripheral & heart arterioles

Verapamil, Diltiazem: Above + Decreased contractility, Decreased HR, Decreased AV conduction

Examples: nifedipine (Adalat) — Others: amlodipine (Norvasc), felodipine (Plendil), nicardipine (Cardene), verapamil (Calan), diltiazem (Cardizem)

Therapeutic Uses:

All: Hypertension, All but Felodipine: Angina, Verapamil, Diltiazem: Hypertension, Angina, Dysrhythmias

Adverse Effects:

Nifedipine: Tachycardia, peripheral edema, acute toxicity

Verapamil, Diltiazem: Orthostatic hypotension, peripheral edema, constipation, cardiac suppression, dysrhythmias, acute toxicity

Contraindications/Precautions:

CI: heart block, hypotension, bradycardia, aortic stenosis, severe heart failure

Interactions:

Verapamil, Diltiazem

Grapefruit leads to toxicity, Digoxin leads to increased [digoxin], β-blockers: leads to HF, AV block, bradycardia

Nifedipine:

Grapefruit leads to toxicity, β-blockers: Used to Decreased reflex tachycardia

Education:

Administer IV over 2-3 minutes

Meds for Hypertensive Crisis

Expected Action:

Direct vasodilation of veins and arteries causing rapid Decreased BP (preload/afterload)

Proto: nitroprusside — Others: labetalol (Trandate), diazoxide (Hyperstat), fenoldopam (Corlopam), trimethaphan (Arfonad)

Therapeutic Uses:

Hypertensive emergencies, Decreased bleeding during surgery by producing controlled hypotension

Adverse Effects:

Excessive hypotension

Cyanide poisoning: increased risk ĉ liver dysfunction; Give slowly (5 mcg/kg/min) along with thiosulfate to deactivate cyanide.

Thiocyanate poisoning: Can manifest as altered mental state/psychosis. Avoid prolonged use (>3 d). Plasma thiocyanate should be <0.1 mg/mL

Contraindications/Precautions:

Pregnancy (C)

Education:

Discard solutions that are blue, red, or green

Protect solutions from light

Do not mix other meds ĉ nitroprusside.

Organic Nitrates

Expected Action:

ò cardiac O₂ demand by dilating veins and decreasing venous return (preload)

Relaxes or prevents spasms in coronary arteries thus increased O₂ supply

Proto: nitroglycerine — Others: isosorbide dinitrate (Imdur)

Therapeutic Uses:

Treatment of angina (acute, variant, and prophylaxis)

IV perioperative BP control, HF d/t acute MI

Adverse Effects:

Headache, Tolerance, Orthostatic hypotension, Reflex tachycardia – give metoprolol (Lopressor)

Contraindications/Precautions:

CI: traumatic head injury leads to increased ICP

Interactions:

Sildenafil (Viagra) leads to Acute or fatal hypotension

EtOH, β-blockers, Ca-blockers, diuretics – additive hypotensive effects

Education:

Sublingual tab/translingual spray: R onset, S duration

Transmucosal: R onset, L duration

SR caps: S onset, L duration

Transdermal: S onset, L duration (hairless area, min 8 hr/day without med to lower risk of developing tolerance.

Topical: S onset, L duration

IV: Use glass bottle & mfr’s tubing; Start at slow rate (5 mcg/min)

Cardiac Glycosides

Expected Action:

(+) inotropic leads to increased SV, CO
(-) chronotropic leads to > fill time leads to increased SV, CO

Proto: digoxin

Adverse Effects:

GI effects, CNS effects (fatigue, vision changes), Dysrhythmias, cardiotoxicity: increased risk from leads to decreased K⁺, Decreased [digoxin], heart disease

Contraindications/Precautions:

CI: v-fib, v-tach, 2/3º blocks

Interactions:

Quinidine leads to increased dig toxicity

Verapamil leads to increased [digoxin]

Sympathomimetics add to inotropic effect

Loop & thiazide diuretics leads to Decreased K⁺ leads to increased risk of digoxin dysrhythmia

ACE inhibitors / ARBs leads to increased risk increased K⁺ leads to ò therapeutic digoxin effects

Education:

Check apical pulse: hold < 60 (adults), < 70 (kids), < 90 (infants)

Therapeutic levels = 0.5-2 ng/mL

Treat bradycardia ĉ atropine