Patients should be informed of possible side effects and advised to take the medication regularly and continuously as directed.

Patients should be told that headaches often accompany treatment with BiDil (isosorbide dinitrate and hydralazine hcl) , especially during initiation of treatment. Headaches tend to subside even with continued dosing. Patients should be instructed to consult a physician to adjust the dose of BiDil (isosorbide dinitrate and hydralazine hcl) if headache continues with repeated dosing. Treatment of emerging headache was managed with acetaminophen in some clinical trial patients.

Treatment with BiDil (isosorbide dinitrate and hydralazine hcl) may be associated with lightheadedness on standing, especially after rising from a recumbent or seated position.

Patients should be cautioned that inadequate fluid intake or excessive fluid loss from perspiration, diarrhea or vomiting may lead to an excessive fall in blood pressure and cause lightheadedness or even syncope. If syncope does occur, BiDil (isosorbide dinitrate and hydralazine hcl) should be discontinued, and the prescribing physician should be notified as soon as possible.

Patients should be cautioned about the increased risk of hypotension especially if they are taking antihypertensive drugs concomitantly.

Patients should be cautioned against concomitant use of BiDil (isosorbide dinitrate and hydralazine hcl) with phosphodiesterase-5 inhibitor drugs used for the treatment for erectile dysfunction or pulmonary hypertension such as sildenafil citrate (Viagra®; Revatio†), vardenafil (Levitra®) or tadalafil (Cialis®). Use of BiDil (isosorbide dinitrate and hydralazine hcl) may produce an extreme drop in blood pressure that may result in fainting or may provoke chest pain or a heart attack.

Last reviewed on RxList: 7/14/2005
This monograph has been modified to include the generic and brand name in many instances.