Brand Name: Apresoline
Generic Name: Hydralazine
| Indications and Clinical Use |
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Hydralazine is indicated for:
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Second-line treatment of hypertension including hypertensive emergencies. The drug is also used to treat hypertension in pregnancy
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As alternative treatment for NYHA class II or III congestive heart failure when used in combination with isosorbide dinitrate for patients who are unable to tolerate ACE inhibitors
Hypertension: Hydralazine is not recognized in contemporary treatment guidelines as a first-line agent for the treatment of hypertension. For the management of essential hypertension, hydralazine is recommended only in patients who do not respond adequately to a combination of first-line antihypertensive agents (e.g., a thiazide diuretic and a β-blocker and/or an ACE inhibitor or calcium channel blocking agent or angiotensin II antagonist). The 2005 Canadian Hypertension Education Program Recommendations mention hydralazine only as a second-line agent in combination with isosorbide dinitrate in patients with hypertension and congestive heart failure.
Hydralazine is generally administered in combination with a thiazide diuretic and a β-blocker. This reduces the hydralazine-induced sodium and water retention and reflex tachycardia, permits use of lower dosages of each drug and minimizes the probability of adverse effects.
Congestive Heart Failure: ACE inhibitors are more effective and better tolerated and are considered to be the cornerstone of treatment for congestive heart failure. However, in a large, methodologically sound, randomized trial, the combination of hydralazine at doses up to 300 mg/day plus isosorbide dinitrate at doses up to 160 mg/day improved exercise tolerance and reduced mortality in patients with chronic congestive heart failure who were receiving cardiac glycosides and diuretics without an ACE inhibitor. Therefore, the combination of hydralazine and isosorbide dinitrate is recommended as an alternative in patients who cannot tolerate ACE inhibitors.
The 2005 Canadian Hypertension Education Program Recommendations state that hydralazine should be avoided in patients with hypertension and left ventricular hypertrophy. Hydralazine has not been shown to produce regression of left ventricular hypertrophy, therefore other agents are preferred.
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Hypersensitivity to hydralazine or to any ingredient in the formulation or component of the container.
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Acute dissecting aortic aneurysm
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Cor pulmonale
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Mitral valve rheumatic heart disease
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Myocardial insufficiency due to mechanical obstruction (e.g., aortic or mitral stenosis or constrictive pericarditis)
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Severe tachycardia and heart failure with high cardiac output (i.e., thyrotoxicosis)
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Systemic lupus erythematosus (SLE)
Hydralazine is associated with the development of antinuclear antibodies and a potentially fatal SLE-like syndrome that manifests most often as fever, arthralgia, asthenia, myalgia, malaise, lymphadenopathy, splenomegaly, pleuritic chest pain and edema. Development of antinuclear antibodies (ANA) does not necessarily predict the onset of the SLE-like syndrome, as approximately 30 to 60% of patients develop a positive ANA titre after 3 years of therapy with hydralazine. The SLE-like syndrome is thought to be a type of hypersensitivity reaction in which hydralazine-directed antibodies and anti-DNA antibodies arise.
The SLE-like syndrome most often develops with the use of doses > 200 mg/day although it has been reported with lower doses. The onset usually is 1 month to 5 years after the start of therapy with hydralazine and usually manifests as arthralgia and arthritis (95% of patients), fever and myalgia (50%) and as pleuropulmonary symptoms (30% of patients; pleurisy, pleural effusions, pulmonary infiltrates). The clinical syndrome usually resolves after withdrawal of hydralazine. |
