Cardiovascular pharmacology

Koss Allied Health Pharmacology 2010

CARDIOVASCULAR PHARMACOLOGY

HYPERTENSION (Diuretics) ANTI-LIPID DRUGS


ANTIHYPERTENSIVE DRUGS Introduction Worldwide, hypertensive disease is one of the most common and most serious concerns in medicine. It is estimated that between 25 and 45 million individuals suffer from hypertension in the United States alone. Although high blood pressure itself is relatively asymptomatic, hypertensive disease is the main contributor to other life threatening conditions such as stroke, heart failure, coronary artery disease and renal failure. Hypertensive patients are generally treated by pharmacological means. There is little doubt that effective treatment will greatly reduce the incidence of progressive cardiovascular and renal complications. In general terms hypertension is divided into arbitrary ranks of severity: being mild if diastolic pressure is 90-105 mm Hg, moderate at 105-120 mm Hg, and severe above 120 mm Hg. Blood pressure gradually increases as a normal consequence of the aging process. A sustained blood pressure in excess of 130 mm Hg requires immediate medical attention. In some patients, blood pressure can be lowered by decreasing sodium intake, by weight control and by exercise. About 10% of hypertensive patients have high blood pressure secondary to some known, underlying organic problem such as pheochromocytoma or renal disease. In these cases the underlying defect should be addressed. Patients with hypertension of unknown etiology are generally referred to as having "essential" hypertension (early investigators felt that the elevated blood pressure was "essential" to perfusion of the vital organs). The ultimate aim of anti-hypertensive therapy is to produce a sustained lowering of blood pressure by reducing total peripheral resistance or TPR (almost all hypertensive patients have normal cardiac output and elevated TPR). Although we are fortunate to have a wide variety of drugs available for therapy, the patient must continually take the medication for it to be effective. To achieve an effective response and patient compliance, the choice of agents must be individualized for each patient. Compliance by the patient to take drugs which have untoward side effects is one of the greatest problems you will encounter. Consequently, emphasis in this section will also concern common side effects of the anti-hypertensive agents. Polytherapy is the rule in anti-hypertensive therapy. One can often obtain the same degree of pressure reduction by using lower doses of several different classes of anti-hypertensive agents and thus minimize untoward effects seen with higher doses of a single drug. With the above factors in mind, we will focus on the mechanism of action and potential side effects of many of the most commonly used anti-hypertensive drugs.


DIURETICS Renal Anatomy & Physiology


Sites of action of Diuretic Drugs

Diuretic Drugs: Chlorothiazide [DIURIL] Furosemide [LASIX] Spironolactone [ALDACTANE]


Angiotensin Antagonists: Angiotensin Converting Enzyme (ACE) inhibitors: Lisinopril [PRINIVIL; ZESTRIL] Angiotensin Receptor Antagonists: Losartan [COZAAR]


ANTIHYPERTENSIVE DRUGS

MECHANISM OF

ACTION

DRUG CATEGORY

DRUGS

DIURETICS

Thiazides and related agents

Chlorothiazide (Diuril)

Loop Diuretics Furosemide (Lasix)

Potassium-sparing diuretics

Spironolactone (Aldactone)

SYMPATHOLYTIC DRUGS

Centrally acting agents

Clonidine (Catapres)

Beta-adrenoceptor antagonists

Propranolol (Inderal) Metoprolol (Lopressor) Atenolol (Tenormin)

Alpha-adrenoceptor antagonists

Prazosin (Minipress) Terazosin (Hytrin) Doxazosin (Cardura)

Mixed antagonist (Alpha & Beta)

Labetalol (Normodyne, Trandate, Vescal)

DIRECT VASODILATORS

Arterial vasodilators

Minoxidil (Loniten)

Calcium antagonists

Amlodipine (Norvasc) Verapamil (Isoptin, Calan) Nifedipine (Procardia, Adalat) Diltiazem (Cardizem, Dilacor)

Arterial and venous vasodilators

Sodium nitroprusside (Nipride, Nitropress)

ANGIOTENSIN ANTAGONISTS

Converting enzyme inhibitors

Lisinopril (Prinivil, Zestril)

Angiotensin receptor antagonist

Losartan (Cozaar) Valsartin (Diovan)


ANTI-LIPID DRUGS Pathophysiology

Site of Action of Anti-Lipid Drugs

Inhibitor of VLDL secretion: Niacin (vitamin B3) Bile Acid-Binding Resins: Cholestyramine [QUESTRAN] Inhibitors of Cholesterol Synthesis (“statins”): Atorvastatin [LIPITOR] Simvastatin [ZOCOR} Inhibitor of Cholesterol Absorption: Ezetimibe [ZETIA] (plus simvastatin = vytorin)

Cardiovascular pharmacology

Health & Medicine

Transcript of Cardiovascular pharmacology