McKenna's Pharmacology for Nursing, 2e

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P A R T 8  Drugs acting on the cardiovascular system

■■ BOX 43.2  Fixed-combination drugs for the treatment of hypertension

■■ BOX 43.3  Treatment of pulmonary arterial hypertension

Many people require more than one type of antihypertensive to achieve good control of their blood pressure. There are now many fixed-combination drugs available for treating hypertension. This allows for fewer tablets or capsules each day, making it easier for the person to comply with drug therapy. The person should be stabilised on each drug first, and then an appropriate combination product can be used. amlodipine with valsartan ( Exforge ) amlodipine with valsartan and hydrochlorothiazide ( Exforge HCT ) candesartan with hydrochlorothiazide ( Adesan HCT , Atacand Plus ) eprosartan with hydrochlorothiazide ( Teveten Plus ) fosinopril with hydrochlorthiazide ( Fosetic , Hyforil Monoplus ) irbesartan with hydrochlorothiazide ( Avapro HCT , Karvezide , KSART HCT ) olmesartan with hydrochlorothiazide ( Olmetec Plus ) perindopril with amlodipine ( Coveram , Reaptan ) perindopril with indapamide ( Coversyl Plus , Perindo Combo , Indosyl Combi ) quinapril with hydrochlorothiazide ( Accuretic ) telmisartan with amlodipine ( Twynsta ) telmisartan with hydrochlorothiazide ( Micardis Plus ) trandolapril with verapamil ( Tarka ) valsartan with hydrochlorothiazide ( Co-Diovan ) lercanidipine with enalapril ( Zan-Extra ) olmesartan with amlodipine ( Sevikar )

In late 2001, bosentan ( Tracleer ) became the first endothelin receptor antagonist to be approved for use in the treatment of pulmonary arterial hypertension. This drug specifically blocks receptor sites for endothelin (ET a and ET b ) in the endothelium and vascular smooth muscles; these endothelins are chemicals that are elevated in the plasma and lung tissues of people with pulmonary arterial hypertension. Blockade of these receptor sites allows the vessels to relax and dilate, relieving the pressure in the arteries. Tracleer is an oral drug that is given to adults, initially as 62.5 mg PO b.d. for 4 weeks, and then increased to 125 mg PO b.d. if the person’s exercise tolerance improves on the drug. People need to be monitored closely for any change in their respiratory function, signs of liver toxicity, or signs of peripheral vasodilation, including flushing, headache, hypotension and palpitations. The drug is pregnancy category X and is known to interact with other drugs, including ketoconazole, the statins, glyburide and oral contraceptives. In 2005, sildenafil, a drug known for the treatment of erectile dysfunction, was approved for the treatment of pulmonary arterial hypertension. Revatio is an oral drug, with 20 mg given three times a day. The doses should be at least 4–6 hours apart. Revatio inhibits cGMP; this allows nitrous oxide in the blood vessel to cause smooth muscle relaxation and decreases vessel pressure (see Chapter 41).

TABLE 43.2

DRUGS IN FOCUS Antihypertensive agents

Drug name

Dosage/route

Usual indications

Angiotensin-converting-enzyme (ACE) inhibitors captopril (Capoten, Zedace)

50–100 mg PO t.d.s. for heart failure (HF); 50 mg PO t.d.s. for ventricular dysfunction; 25 mg PO t.d.s. for diabetic nephropathy; reduce dose in people with renal impairment and in geriatric people 10–40 mg/day PO; reduce dose in geriatric people and people with renal impairment; 2.5 mg PO b.d. for HF or left ventricular dysfunction 20–40 mg/day PO for hypertension; 5–20 mg/day PO for HF; 5–10 mg/day PO after MI; decrease dose in geriatric people and people with renal impairment 4 mg/day PO; reduce dose in geriatric people and people with renal impairment 10–40 mg/day PO

Treatment of left ventricular dysfunction after myocardial infarction (MI), diabetic nephropathy; for use in adults

enalapril (Acetec, Amprace, Renitec)

Treatment of hypertension, HF, left ventricular dysfunction in adults

fosinopril (Monace, Monopril)

Treatment of hypertension; adjunct therapy for HF; for use in adults Treatment of hypertension, HF; treatment of stable people within 24 hours after acute MI to increase survival; for use in adults Treatment of hypertension; may be used alone or as combination drug to control blood pressure; for use in adults

lisinopril (Fibsol, Prinivil, Zestril)

perindopril (Coversyl, Indopril, Perindo)