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)