HTN/CHF Flashcards
Lisinopril (Prinivil, Zestril)
Drug class: ACE inhibitor
Indications: CHF, antihypertensive preserving kidney function, preserving LV function after MI, acute management of MI
Dynamics: inhibits conversation of AT1 to AT2, diminishes both vasoconstriction and stimulation of aldosterone secretion by AT2.
Kinetics: well-absorbed, onset 1h, peak 6h, duration 24h, qd is fine, excreted renally unchanged.
Toxicity: orthostatic hypotension, use with caution in pts with impaired renal function, or renal artery stenosis, be careful with pts on diuretics, or those with aortic stenosis, angiodema, cough, acute renal failure
Interactions: additive with other antihypertensives, NSAIDs may reduce ability to lower BP, hyperkalemia with KCl
Special considerations: often discontinue diuretics prior to beginning use to reduce hypotension, category C/D in pregnancy, abnormal cartilage development
Monitor: BP, edema, weight, K, creatinine!
Hydrochlorothiazide (Hydrodiuril, Chlothalidone)
Drug class: thiazide diuretic
Dynamics: block reuptake of Cl and Na from tubular fluid after filtration, also appears to decrease SVR, will lower BP 10-15mm in many pts, useful as monotherapy or in combinations
Kinetics: F 70%, excreted unchanged in urine, short half-life, HCTZ not available in IV, onset 2hr, peak 5hr, duration 10hr
Toxicity: allergy to sulfa antibiotics, cause K and Mg depletion, cause Na and Cl depletion, worsen hyperuricemia
Interactions: additive effects with most other antihypertensives
Special considerations: more side effects in geriatric pts, pregnancy class D, much less effective with pts with reduced GFR
Monitor: BP, weight, edema, K, Mg, BUN, creatinine
Losartan (CoZaar)
Drug class: angiotensin 1 receptor blockers (ARB)
Indication: antihypertensive, preserves renal function, treatment of CHF
Kinetics: F ~30%, onset 6h, active metabolite is 40x more potent, much longer half-life
Toxicity: dizziness, orthostatic hypotension, worsening of renal failure
Interactions: additive with antihypertensives
Special consideration: pregnancy class C/D, use care in pts on diuretics, with renal artery stenosis, with mitral or aortic stenosis
Monitor: BP, weight, edema, lytes, BUN, creatinine
Nitroprusside (Nipride, Nitropress)
Drug class: vasodilator
Indication: HTN crisis, severe CHF, pulmonary hypertension, produce controlled hypotension to reduce bleeding in surgery
Dynamics: acts directly on vascular smooth muscle to cause dilation of both veins (major relief of ischemia in pts with typical angina) and arteries, metabolized to release CN- and NO, which activates guanylate cyclase, leads to cGMP, leads to vasodilation, cGMP hydrolyzed by PDE
Kinetics: only route is IV, rapid onset and cessation (minutes), CN- metabolite is converted to SCN in liver, then excreted in urine, must be given by continuous infusion
Toxicity: xs. Hypotension, accumulation of CN and SCN, headache, decreased blood flow to brain
Interaction: additive with most other antihypertensives
Special consideration: monitor pt VERY closely, must be in ICU with arterial line, avoid high infusion rates or prolonged infusions to prevent accumulation of CN-, use with caution for pts with increased cranial pressure.
Monitor: BP, HR, metabolic acidosis, most often requires arterial line.
Hydralazine (Apresoline)
Drug class: peripheral vasodilator
Indication: HTN, CHF, vasodilation
Dynamics: direct acting vasodilator, induce endothelium to produce NO, minimal venodilating effect
Kinetics: given po, im, iv, metabolized extensively in GI mucosa and liver, eventually excreted in urine. F 40%, onset 30min po, 10min iv, persist 2-6h
Toxicity: more dangerous in pts with renal disease, prior stroke, angina, watch for hypotension, edema, occasionally drug-induced LUPUS
Interaction: additive with antihypertensives
Special consideration: never use as chronic monotherapy for treatment of HTN, since edema and reflex tachycardia can result, concern giving to pts with CAD
Monitor: BP, Weight, BUN, Creatinine, symptoms of lupus or angina
Verapamil (Isoptin, Calan)
Drug class: calcium entry blocker
Indications: HTN, angina, arrhythmia
Dynamics: reduces BP by inhibiting calcium influx through slow channels, thereby dilating arterioles, produces negative inotropic effect as well, for angina, reduces afterload, thus decreasing oxygen demand, also inhibits spasm of coronary arteries in vasospastic angina , blocks reentry paths through AV nodes in paroxysmal SVT.
Kinetics: absorbed rapidly, F 30%, also available in SR tablets, cleared by kidney and liver (produces active metabolites), onset 2h po, 1-5min iv, half-life 6-12h
Toxicity: hypotension, AV block, worsening of CHF, bradycardia
Interaction: additive with antihypertensives, additive toxic effects on heart when given with beta blockers
definitely contraindicated in CHF
Special consideration: use reduced doses in pts with both renal and hepatic diseases, short-acting nifedipine can increase risk of MI (unclear why), pregnancy C
Monitor: BP, edema, weight
Clonidine (Catapres)
Drug class: central a2 agonist, adjunct to rx of opioid withdrawal, prophylaxis of migraine
Dynamics: stimulates a2 adenoreceptors in brainstem, leading to downregulation of sympathetic output
Kinetics: onset 1h, duration 8h, F -85%, also available as cutaneous patch
Toxicity: withdraw gradually bc risk of rebound HTN, risk of bradycardia in sinus node disease, fatigue, depression
Interactions: additive effects with most other antihypertensives, additive sedation with other CNS drugs
Special consideration: pregnancy class C, avoid pts with renal insufficiency
Monitor: follow BP, HR, fatigue
Trimethaphan (Arfonad)
Drug class: ganglionic transmission blocker
Dynamic: blocks nicotinic transmission with both sympathetic and parasympathetic ganglia (Nn receptors), produces veno and vasodilation
Kinetics: useful only when given iv, produces fall in BP within minutes, partly metabolized, and partly excreted by kidneys
Toxicity: watch out for sudden drop in BP, also fall in HR, reduced sympathetic and parasympathetic responses
Interactions: with most other antihypertensives
Special consideration: pts are quite miserable, hence ONLY used during general anesthesia, helps to tilt a pt to control BP
Indications: HTN crisis, controlled hypotension during cardiovascular surgery
Monitor: minute to minute monitoring of BP/HR
Reserpine
Drug class: Rauwolfia alkaloid
Dynamics: binds to vesicles that contain NE or serotonin, preventing their uptake, ultimately depleting the neuron of NE,
Kinetics: good oral bioavailability, depletion takes 2-3 wks to develop.
Toxicity: dizziness, orthostatic hypotension, depression
Special consideration: first antihypertensive drug approved by FDA
Atenolol (Tenormin, Propranolol, Metopropol)
Drug class: b1 specific blocker
Indications: HTN, arrhythmia, primary and secondary prevention of MI, angina
Dynamics: bind directly to b adrenergic receptors (1 over 2), leading to lower BP via less CO, less activation of RAA, recent evidence suggests less effective in preventing strokes than other drugs, hence less often used as initial monotherapy in many pts
Kinetics: available po, iv, variable oral F, onset 1-2h, duration 12-24h, renally excreted (longer half life)
Toxicity: xs hypotension, bradycardia, heart block can worsen in severe CHF, worsen bronchospasm in severe asthmatics
Interaction: additive with most other antihypertensives, additive AV block with CEBs
Special consideration: esp useful for HTN pts with exertional angina, MI, afib, watch out for abrupt withdrawal, may no longer be first line drug unless other indications exist
Monitor: BP, HR, exercise tolerance
Prazosin (Minipress, Tamsulosin)
Drug class: a1 blocker
Indications: Hypertension, BPH, Raynaud’s Syndrome, Kidney stones
Dynamics: blocks a1 adrenoreceptors in veins and arterioles, inhibiting NE-mediated vaso and venoconstriction
Kinetics: available po or transdermal, variable oral F (~60%), onset 2h, duration 12-24h, extensively metabolized in liver
Toxicity: xs hypotension with passing out, esp pts with diuretics
Special consideration: start gradually, and at bedtime, to avoid first-time passing out, male pts with BPH
Monitor: BP, weight, edema
Labetalol (Trandate, Carvedilol, Coreg)
Drug class: alpha and beta blocker
Indications: HTN, CHF
Dynamics: reduces BP by blocking access of NE to adrenoreceptors
Kinetics: excellent absorption, but high first-pass effect, leading to F ~25%, onset 1-2h after po, 2-5min after iv, extensively metabolized by IID6 in liver
Toxicity: avoid pts with bradycardia, heartblock, CHF, asthma, shock; use with caution in pts with cardiomyopathy, pheochromocytoma; pregnancy class D
Special consideration: use reduced doses in pts with impaired liver function, dizziness is most troubling first side effect, most often used for hypertensive crisis (as with nitroprusside)
Route: most commonly given iv, with initial small boluses, followed by continuous infusion at 2mg/min, not usually given po for chronic use
Monitor: BP, HR
Digoxin (Digitalis, Lanoxin)
Drug class: glycoside, positive inotropic and anti-arrhythmic
PD: therapeutic levels cause a vagotonic effect that is useful in slowing AV conduction in pts with atrial fibrillation, toxic levels increase automaticity of all areas of the heart except the SA node, increase Ca2+ influx from sarcoplasmic reticulum
PK: bioavailability 60-95% (best with capsule), can be given slowly IV, redistribution over 8hr, clearance 80% renal, t1/2 30-40hrs in normal GFR, markedly high Vd (approx 6-7L/kg)
Toxicity: contraindicated in pts with VTach, VF, hypertrophic cardiomyopathy (IHSS), AV block, WPW syndrome, sinus node disease, hypoxia; common ADRs include nausea, vomiting, visual changes, agitation or nightmares, increased automaticity, AV block
Interactions: antacids (decreased absorption), quinidine (decreased renal clearance), other drugs with additive effects on AV nodal conduction
Special consideration: pts with renal failure, starting quinidine, hold prior to cardioversion
Indications/Dose/Route: for treatment of CHF, and atrial fibrillation or flutter, maybe given po or iv, loading dose sometimes used, maintenance dose usually daily.
