Pharmacotherapy for HTN, DVT Drugs that decrease blood pressure Drugs that decrease fluid volume Drugs that affect coagulation Drug that decreases blood viscosity Herbals

Drugs that Decrease Blood Pressure Alpha-adrenergic blockers—doxasozin (Cardura)* Beta-adrenergic blockers—atenolol (Tenormin) Angiotensin Converting Enzyme Inhibitors (ACEIs)—enalapril (Vasotec) Angiotension Receptor Blockers (ARBs)—losartan (Cozaar)

Drugs to Decrease BP cont’d Calcium-channel blockers—diltiazem (Cardizem) Centrally-acting sympatholytics—clonidine (Catapres)* Vasodilators—minoxidil (Loniten)*

Alpha-Blockers Prototype: doxasozin Note: all generics end in –sozin Action: blocks alpha receptors in vascular smooth muscle, causing vasodilation. Side effects: “first dose syncope”, orthostatic hypotension, tachycardia, palpitations, nasal congestion, impotence. Nursing considerations: Give at hs to minimize risk of fainting. If 1st dose is given in daytime or if dose is increased, instruct pt to remain in bed for 3-4h. Pt is not to drive for 12-24h. Tell pt to change positions slowly.

Beta-Blockers Protoype: atenolol Note: all generics end in –lol Action: blocks beta receptors, slows heart rate, decreases oxygen demand Side effects: fatigue, dizziness, hypotension, bradycardia, bronchospasm (do not use in obstructive or restrictive respiratory diseases), agranulocytosis, thrombocytopenia, ED, depression Nursing considerations: apical/radial pulse before adm. Notify prescriber for P<50, I&O, daily wts. Monitor BP.

ACEIs Prototype: enalapril Note: all generics end in -pril Action: Suppresses renin-angiotensin-aldosterone system; prevents conversion of angiotensin I to angiotension II. Dilates arterial and venous vessels. Side effects: Insomnia, dizziness, hypotension, dysrhythmias, proteinuria, renal failure, agranulocytosis, neutropenia, cough, hyperkalemia Nursing Considerations: Monitor CBC, BP, P. If pt is on diuretic tx, monitor for syncope

ARBs Prototype: losartan Note: all generics end in -sartan Action: Blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II Side effects: Dizziness, insomnia, CVA, MI, dysrhythmias, cough, diarrhea, indigestion, renal failure, angioedema Nursing Considerations: BP, P. Monitor for edema, lytes, hepatic and renal function before tx begins

CCBs Prototype: diltiazem Action: inhibits calcium; dilates coronary and peripheral arteries Side effects: HA, fatigue, drowsiness, dysrhythmias, CHF, heart block, ARF Nursing considerations: Monitor VS, hold for SBP<90, Heart rate<60; monitor ECG

Centrally Acting Sympatholytic Prototype: clonidine Action: stimulate alpha-receptors in the DNS to suppress sympathetic flow to heart and vessels. Suppresses cardiac output and causes vasodilation. Side effects: dry mouth, sedation Nursing considerations: Monitor BP and P. Tell pt not to stop suddenly—may cause severe rebound HTN. Administer at hs to minimize effects of sedation. Contraindicated in pregnancy.

Vasodilators Prototype: minoxidil Action: relaxes vascular smooth muscle, especially arterioles and decreases systemic vascular resistance (SVR). Usually given with BB or diuretic. Side effects: fluid retention, reflex tachycardia, orthostatic hypotension Nursing considerations: Assess BP, P before and during tx. Monitor for edema and hear failure. Tell pt to change positions slowly. And to report muscle or joint aches or fever. May cause excessive hair growth

Drugs that Decrease Fluid Volume Thiazide diuretics—hydrochlorothiazide (HCTZ, HydroDIURIL)

Thiazide Diuretics Prototype: hydrochlorothiazide Action: Increases excretion of water, sodium, chloride, and potassium in the distal tubule and ascending limb of loop of Henle. Indications: Edema, HTN, diuresis, CHF Side effects: Dizziness, weakness, fatigue, hypokalemia, NV, anorexia, hepatitis, aplastic anemia, pancytopenia, glucosuria, allergic reaction (sulfa) Nursing Considerations: Assess daily wts, I&O, postural BPs, lytes, blood sugar

Drugs that Affect Coagulation Drugs interfering with the clotting cascade—heparin sodium (no trade name), low-molecular weight heparin (Lovenox) Drugs that interfere with synthesis of Vitamin K-dependent clotting factors—warfarin (Coumadin)

Anticoagulant #1 Prototype: heparin sodium Action: prevents conversion of fibrinogen to fibrin and prothrombin to thrombin Indications: Tx of pulmonary embolism, DVT Side effects: fever, hemorrhage, rash, thrombocytopenia, anemia, anaphylaxis Nursing considerations: Monitor PTT, CBC, signs of hemorrhage and allergy. If given SQ, give in abdomen. Do not aspirate or massage. Check labels closely so as not to confuse concentrations.

Anticoagulant #2 Prototype: LMWH Action: prevents conversion of prothrombin to thrombin. More precise and predictable than heparin Side effects: hemorrhage, bruising, thrombocytopenia Nursing considerations: abdomen is best site for SQ administration. Do not remove air bubble from syringe before administration. Do not aspirate or massage.

Anticoagulant #3 Prototype: warfarin Action: interferes with blood clotting by depressing hepatic synthesis of Vitamin K-dependent coagulation factors Indications: prevention and tx of pulmonary emboli, DVT Side effects: hepatitis, hemorrhage, WBC effects, rash Nursing considerations: Monitor PT, CBC, and for hemorrhage and occult blood in stools.

Trental (pentoxifylline) Action: Decreases blood viscosity, increases blood flow by increasing flexibility of RBCs Indication: Intermittent claudication Forms: po, po XR Side effects: HA, tremors, dizziness, indigestion, NV, leukopenia Nursing Considerations: Watch BP if pt is on antihypertensives. Assess for improvement in activity with continued use.

Herbals Ingestion of Fish Oil/Omega-3 Fatty Acids has been associated with lower BP readings in people with hypertension Hawthorne may be most commonly used herb for treating HTN, but should not be used with other antihypertensives and with cardiac glycosides