Hydralazine Hydrochloride and Coronary artery disease

• Generic Name: hydralazine
• Dosage Forms: n.a.
• Other Brand Names: Apresoline

Management of hypertension (alone or in combination with other classes of antihypertensive agents).

Not considered a preferred agent for initial management of hypertension according to current guidelines for the management of hypertension in adults, but may be used as add-on therapy if BP not adequately controlled with the recommended antihypertensive drug classes (i.e., ACE inhibitors, angiotensin II receptor antagonists, calcium-channel blockers, thiazide diuretics).

Individualize choice of therapy; consider patient characteristics (e.g., age, ethnicity/race, comorbidities, cardiovascular risk) as well as drug-related factors (e.g., ease of administration, availability, adverse effects, cost).

A 2017 ACC/AHA multidisciplinary hypertension guideline classifies BP in adults into 4 categories: normal, elevated, stage 1 hypertension, and stage 2 hypertension.

Source: Whelton PK, Carey RM, Aronow WS et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018;71:e13-115.

Individuals with SBP and DBP in 2 different categories (e.g., elevated SBP and normal DBP) should be designated as being in the higher BP category (i.e., elevated BP).

The goal of hypertension management and prevention is to achieve and maintain optimal control of BP. However, the BP thresholds used to define hypertension, the optimum BP threshold at which to initiate antihypertensive drug therapy, and the ideal target BP values remain controversial.

The 2017 ACC/AHA hypertension guideline generally recommends a target BP goal (i.e., BP to achieve with drug therapy and/or nonpharmacologic intervention) of <130/80 mm Hg in all adults regardless of comorbidities or level of atherosclerotic cardiovascular disease (ASCVD) risk. In addition, an SBP goal of <130 mm Hg generally is recommended for noninstitutionalized ambulatory patients ≥65 years of age with an average SBP of ≥130 mm Hg. These BP goals are based upon clinical studies demonstrating continuing reduction of cardiovascular risk at progressively lower levels of SBP.

Other hypertension guidelines generally have based target BP goals on age and comorbidities. Guidelines such as those issued by the JNC 8 expert panel generally have targeted a BP goal of <140/90 mm Hg regardless of cardiovascular risk, and have used higher BP thresholds and target BPs in elderly patients compared with those recommended by the 2017 ACC/AHA hypertension guideline.

Some clinicians continue to support previous target BPs recommended by JNC 8 due to concerns about the lack of generalizability of data from some clinical trials (e.g., SPRINT study) used to support the 2017 ACC/AHA hypertension guideline and potential harms (e.g., adverse drug effects, costs of therapy) versus benefits of BP lowering in patients at lower risk of cardiovascular disease.

Consider potential benefits of hypertension management and drug cost, adverse effects, and risks associated with the use of multiple antihypertensive drugs when deciding a patient's BP treatment goal.

For decisions regarding when to initiate drug therapy (BP threshold), the 2017 ACC/AHA hypertension guideline incorporates underlying cardiovascular risk factors. ASCVD risk assessment is recommended by ACC/AHA for all adults with hypertension.

ACC/AHA currently recommend initiation of antihypertensive drug therapy in addition to lifestyle/behavioral modifications at an SBP ≥140 mm Hg or DBP ≥90 mm Hg in adults who have no history of cardiovascular disease (i.e., primary prevention) and a low ASCVD risk (10-year risk <10%).

For secondary prevention in adults with known cardiovascular disease or for primary prevention in those at higher risk for ASCVD (10-year risk ≥10%), ACC/AHA recommend initiation of antihypertensive drug therapy at an average SBP ≥130 mm Hg or an average DBP ≥80 mm Hg.

Adults with hypertension and diabetes mellitus, chronic kidney disease (CKD), or age ≥65 years are assumed to be at high risk for cardiovascular disease; ACC/AHA state that such patients should have antihypertensive drug therapy initiated at a BP ≥130/80 mm Hg. Individualize drug therapy in patients with hypertension and underlying cardiovascular or other risk factors.

In stage 1 hypertension, experts state that it is reasonable to initiate drug therapy using the stepped-care approach in which one drug is initiated and titrated and other drugs are added sequentially to achieve the target BP. Consider initiation of antihypertensive therapy with 2 first-line agents from different pharmacologic classes in adults with stage 2 hypertension and average BP >20/10 mm Hg above BP goal.

Severe Hypertension and Hypertensive Crises

One of several recommended parenteral agents for use in the hospital setting to urgently lower BP in severely hypertensive pregnant women, including those with preeclampsia.

Historically considered the agent of choice for management of hypertensive emergencies associated with pregnancy (e.g., preeclampsia, eclampsia); however, some clinicians prefer IV labetalol for its more rapid onset, shorter duration of action, and more predictable hypotensive effect.

Parenteral management of severe hypertension when the drug cannot be given orally or when BP must be lowered immediately; other parenteral antihypertensive agents (e.g., labetalol, esmolol, fenoldopam, nicardipine, sodium nitroprusside) usually are preferred for these indications.

Not recommended for the management of severe hypertension or hypertensive emergencies associated with cerebrovascular accidents or in patients with cerebral edema and encephalopathy.

Heart Failure

Used in fixed combination with isosorbide dinitrate as adjunct to standard therapy for the treatment of heart failure in self-identified black patients to improve survival, decrease rate of hospitalization for worsened heart failure, and improve patient-reported functional status.

Current guidelines recommend a combination of drug therapies (e.g., ACE inhibitors, angiotensin II receptor antagonists, angiotensin receptor-neprilysin inhibitors [ARNIs], β-adrenergic blocking agents [β-blockers], aldosterone receptor antagonists) in adults with heart failure to reduce morbidity and mortality.

Combination of hydralazine and isosorbide dinitrate recommended by ACCF and AHA for self-identified black patients with NYHA class III or IV heart failure and reduced ejection fraction who are receiving optimal therapy with ACE inhibitors and β-blockers, unless contraindicated.

ACCF and AHA state that combined therapy with hydralazine and isosorbide dinitrate also can be useful in patients with current or prior symptomatic heart failure with reduced ejection fraction who cannot receive an ACE inhibitor or angiotensin II receptor antagonist because of drug intolerance, hypotension, or renal insufficiency.