Hipertensión Arterial

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The DASH (Dietary Approaches to Stop Hypertension) trial convincingly demonstrated that over an 8-week period a diet high in fruits, vegetables, and low-fat dairy products lowers blood pressure in individuals with high-normal blood pressures or mild hypertension. Reduction of daily NaCl intake to <6 g (100 meq) augmented the effect of this diet on blood pressure.Fruits and vegetables are enriched sources of potassium, magnesium, and fiber, and dairy products are an important source of calcium.Pharmacologic TherapyDrug therapy is recommended for individuals with blood pressures 140/90 mmHg. The degree of benefit derived from antihypertensive agents is related to the magnitude of the blood pressure reduction. Lowering systolic blood pressure by 10–12 mmHg anddiastolic blood pressure by 5–6 mmHg confers relative risk reductions of 35–40% for stroke and 12–16% for CHD within 5 years of the initiation of treatment. Risk of heart failure is reduced by >50%. Hypertension control is the single most effective intervention for slowing the rate of progression of hypertension-related chronic kidney disease.There is considerable variation in individualresponses to different classes of antihypertensive agents, and the magnitude of response to any single agent may be limited by activation of counterregulatory mechanisms that oppose the hypotensive effect of the agent. Most available agents reduce systolic blood pressure by 7–13 mmHg and diastolic blood pressure by 4–8 mmHg when corrected for placebo effect. More often than not, combinations of agents,with complementary antihypertensive mechanisms, are required to achieve goal blood pressure reductions. Selection of antihypertensive agents and combinations of agents should be individualized, taking into account age, severity of hypertension, other cardiovascular disease risk factors, comorbid conditions, and practical considerations related to cost, side effects, and frequency of dosing (Table247-8). Table 247–8. Examples of Oral Drugs Used in Treatment of Hypertension |
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Drug Class | Examples | Usual Total Daily Dose* (Dosing Frequency/Day)
  | Other Indications | Contraindications/Cautions |
Diuretics |
  Thiazides | Hydrochlorothiazide | 6.25–50 mg (1–2) |   | Diabetes, dyslipidemia, hyperuricemia, gout, hypokalemia |
| Chlorthalidone | 25–50 mg (1) |   | |
  Loopdiuretics | Furosemide | 40–80 mg (2–3) | CHF due to systolic dys-function, renal failure | Diabetes, dyslipidemia, hyperuricemia, gout, hypokalemia |
| Ethacrynic acid | 50–100 mg (2–3) | | |
  Aldosterone antagonists | Spironolactone | 25–100 mg (1–2) | CHF due to systolic dysfunction, primary aldosteronism | Renal failure, hyperkalemia |
| Eplerenone | 50–100 mg (1–2) | | |
  K+retaining
  | Amiloride | 5–10 mg (1–2) |   | Renal failure, hyperkalemia |
| Triamterene | 50–100 mg (1–2) |   | |
Beta blockers |
  Cardioselective | Atenolol | 25–100 mg (1) | Angina, CHF due to systolic dysfunction, post-MI, sinus tachycardia, ventricular tachyarrhythmias | Asthma, COPD, 2nd- or 3rd-degree heart block, sick-sinus syndrome |
| Metoprolol | 25–100 mg (1–2) | | |  Nonselective | Propranolol | 40–160 mg (2) | | |
| Propranolol LA | 60–180 (1) | | |
  Combined alpha/beta | Labetalol | 200–800 mg (2) | ?Post-MI, CHF |   |
| Carvedilol | 12.5–50 mg (2) |   |   |
Alpha antagonists |
  Selective | Prazosin | 2–20 mg (2–3) | Prostatism |   |
| Doxazosin | 1–16 mg (1) |   |   |
| Terazosin | 1–10 mg (1–2) |   |   |
  Nonselective |Phenoxybenzamine | 20–120 mg (2–3) | Pheochromocytoma |   |
Sympatholytics |
  Central | Clonidine | 0.1–0.6 mg (2) |   |   |
| Clonidine patch | 0.1–0.3 mg (1/week) |   |   |
| Methyldopa | 250–1000 mg (2) |   |   |
| Reserpine | 0.05–0.25 mg (1) |   |   |
| Guanfacine | 0.5–2 mg (1) |   |   |
ACE inhibitors | Captopril | 25–200 mg (2) | Post-MI, coronary syndromes, CHF with low...