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Week-5 ------ MR160 Week-5 ------ MR160
the Circulatory the Circulatory SystemSystemChapter 20
CIRCULATORY overviewCIRCULATORY overviewHEART innervated muscle tissue
BLOOD VESSELS - Pulmonary - Systemic - Coronary*************************** see Fig.
20-1
Drug affects on the Drug affects on the HEARTHEARTRATERHYTHM (heartbeat)OUTPUT (volume of blood pumped)STRENGTH of contraction ENERGY production of the heart
muscle----‘Cardiac’ drugs mainly used to
treat----Heart-failure(CHF), Myocardial-infarction(MI),& Arrythmias
Heart failure (CHF)Heart failure (CHF)Congestive heart failure (CHF)Blood not being circulated at
sufficient rate to meet body’s demands –pooling-
Suspected when patient must elevate upper-body to breathe while lying down
----- the REMEDY?* increase ‘strength-of-contraction’ and* reduce excess water, blood-volume • Why would these things help?
DRUGS DRUGS for heart failure for heart failure ……INOTROPIC’s (digoxin, digitalis) strengthen ‘squeezing’, contractionDIURETIC’s (hctz, furosemide) reduce blood-volume, heart’s ‘load’ … imagine pushing a boulder uphill!
ACE’s (enalapril, lisinopril, quinapril) increases energy in cardiac-muscle
ARRHYTHMIASARRHYTHMIAS SA(sino-atrial)node - natural
pacemaker, controls heart’s RATE and RHYTHM
Generates tiny ELECTRICAL impulses that cause contraction
Arrhythmia is any disturbance of ‘normal’
Fast, slow, or erratic (unpredictable!)------ the REMEDY?** stabilize these electrical-impulses !
DRUGS DRUGS for arrhythmiafor arrhythmiaCalled anti-arrhythmics (of
course!)Pacerone, Cardarone
(amiodarone)Betapace (sotalol)Quinidine sulfateNorpace (disopyramide)Tikosyn (dofelitide)Lidocaine Hcl --- IV, injectable
VASOCONSTRICTORSVASOCONSTRICTORSConstrict (tighten) blood vessel walls----- used primarily to ---------------------• Stop SUPERFICIAL BLEEDING• Relieve NASAL CONGESTION• Raise BLOOD PRESSURE• Increase FORCE of the heart’s action
* epinephrine – powerful constrictor!* Afrin – constricts nasal vessels
VASOVASODILATORSDILATORSRELAX blood vessels, increasing
diameter------- used to treat ------------------• Hypertension (reduces BP)• Heart conditions (**NTG for angina &
chest-pain)• Peripheral VASCULAR disease** nitrates & nitrites – nitroglycerin
(NTG) sublingual, transdermal patch, cream/oint.
BETA blockers * atenolol(Tenormin, Toprol-XL)ALPHA blockers * doxazosin(Cardura),
terazosin(Hytrin)CALCIUM CHANNEL blockers * amlodipine(Norvasc),
nifedipine(Procardia)central ALPHA agonists * clonidine(Catapres tablets & patches)
COAGULANTS * vitamin-K (Mephyton)- fat soluble
vitamin * calcium salts (gluconate, chloride,
lactate)AntiCOAGULANTS ---many DDI’s------ (see Box 20-1 on page 102)
Heparin – injectable Lovenox – self-administered
injectable Coumadin(warfarin) – oral tablets
Cholesterol Lowering Cholesterol Lowering agentsagentsknown as the antiLIPIDEMIC’s because
they reduce overall lipid (cholesterol) levels in the blood (goal = <160mg/dL)
HDL = ‘good cholesterol’ (> 30) *carries cholesterol to the liver for
storageLDL = ‘bad cholesterol’ (< 70) *carries cholesterol from liver to the
blood--- Dietary changes should be tried first
--- ----- NOT USED IN PREGNANCY! -----
ANTILIPIDEMICS – ANTILIPIDEMICS – Drug Drug ClassesClassesSTATINS (HMG CoA reductase
inhibitors) * atorvastatin (Lipitor) * lovastatin (Mevacor) * simvastatin (Zocor) * pravastatin (Pravachol)fibric acid derivatives
(triglycerides/HDL) * gemfibrozil (Lopid)misc agents – ezetimibe (Zetia)
Autonomic Nervous Autonomic Nervous SystemSystemAutonomic Nervous Autonomic Nervous SystemSystemLet’s begin chapter-25 …the ANS made up of 2-parts:SympatheticParasympathetic * If one system stimulates a
function, the other tends to inhibit it … they oppose each other
----------- see Table 25-1 for examples ------------
These agents ‘mimic’ the stimulation of the SNS (why ‘mimetic’ is in name)
epinephrine (Adrenalin, Epi-Pen) * naturally produced by adrenal-glands * … “fight or flight” response
(adrenergic)phenylephrine (Neo-Synephrine) * commonly found in NASAL SPRAYS
for relief of nasal-congestion
sympathoLYTICs agents …sympathoLYTICs agents …sympathoLYTICs agents …sympathoLYTICs agents …… adrenergic BLOCKING agents are
classified by the receptor which they’re most specific
--- these drugs nullify stimulation of the SNS, so their effect is like stimulation of the PSNS!
Alpha-blockers * methyldopa (Aldomet)Beta-blockers * propranolol (Inderal)
These “mimic” the effect of PSNS stimulation
acetylcholine-like effects (ie, cholinergic)
* bethanechol (Urecholine) * pilocarpine * neostigmine (Prostigmin) * edrophonium
Drugs that oppose or nullify the stimulation of the PSNS … so they have the same ‘net’ effect as stimulation of the SNS
Also known as the ‘Cholinergic Blockers’
* atropine sulfate * clidinium bromide (Librax) * dicyclomine (Bentyl)