• Basic Info
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What is hydralazine?
Hydralazine is a vasodilator that works by relaxing the muscles in your blood vessels to help them dilate (widen). This lowers blood pressure and allows blood to flow more easily through your veins and arteries. Hydralazine is used to treat high blood pressure (hypertension). Hydralazine may also be used for other purposes not listed in this medication guide.

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What is the price of this medication and similar alternatives?

This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit drugstore.com.

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What are the possible side effects of hydralazine?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

• fast or pounding heartbeats;

• swelling in your face, stomach, hands, or feet;

• numbness, burning, pain, or tingly feeling;

• feeling like you might pass out;

• confusion, unusual thoughts or behavior;

• pale skin, easy bruising;

• painful or difficult urination;

• dark-colored urine;

• urinating less than usual or not at all; or

• joint pain or swelling with fever, chest pain, weakness or tired feeling.

Less serious side effects may include:

• nausea, vomiting, loss of appetite;

• diarrhea, constipation;

• headache;

• dizziness;

• anxiety;

• muscle or joint pain;

• runny or stuffy nose; or

• mild itching or skin rash.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

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How should I take hydralazine?
Take this medication exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label. To be sure this medication is helping your condition and is not causing harmful effects, your blood pressure will need to be checked often. You may also need occasional blood tests. Do not miss any scheduled appointments. Keep using hydralazine as directed, even if you feel well. High blood pressure often has no symptoms, so you may not know when your blood pressure is high. You may need to use blood pressure medication for the rest of your life.

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What is the most important information I should know about hydralazine?
You should not use this medication if you are allergic to hydralazine, or if you have coronary artery disease, or rheumatic heart disease affecting the mitral valve. Before taking hydralazine, tell your doctor if you have kidney disease, lupus, angina pectoris (chest pain), or if you have ever had a stroke. While taking hydralazine, avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall. Call your doctor at once if you have a serious side effect such as fast or pounding heartbeats, swelling, numbness or tingling, dark-colored urine, joint pain or swelling with fever, chest pain, weakness or tired feeling, and urinating less than usual or not at all.

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What happens if I miss a dose?
Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.

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What other drugs will affect hydralazine?
Before taking hydralazine, tell your doctor if you are taking any of the following medicines: diazoxide (Hyperstat, Proglycem); or an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate). This list is not complete and there may be other drugs that can interact with hydralazine. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

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Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?

Hydralazine has been assigned to pregnancy category C by the FDA. Animal studies have revealed evidence of teratogenicity after doses 20 to 30 times the maximum recommended daily human dose (on a per kg basis) were given to mice. Teratogenicity was possibly related to hydralazine after doses 10 to 15 times the maximum recommended daily human dose (on a per kg basis) were given to rabbits. There are no controlled data in human pregnancy. Hydralazine should only be given during pregnancy when benefit outweighs risk.

In general, hydralazine has been used extensively and safely for the treatment of maternal hypertension during pregnancy. There are reports of neonatal asymptomatic and symptomatic thrombocytopenia and maternal and fetal lupus-like syndromes. Among 50,282 mother-child pairs monitored in the Collaborative Perinatal Project, 136 instances of the use of hydralazine during pregnancy were found. Of the 136 pairs, eight malformed children were observed at "anytime" during pregnancy (3.8 were expected from the population studied), yielding a standardized relative risk of 2.09. Underlying preeclampsia makes implication of drug therapy alone difficult. Data from the Michigan Medicaid Birth Defects Study (MMBDS) failed to reveal an association between the use of hydralazine and congenital abnormalities (written communication, Franz Rosa, MD, Food and Drug Administration, 1994). The MMBDS is a retrospective study of 229,101 completed pregnancies between 1985 and 1992, of which 40 were exposed to hydralazine at some time during the first trimester, and 341 were exposed to the drug at any time during pregnancy. These data do not support an association between hydralazine and birth defects. However, results of a meta-analysis comprised of randomized controlled trials do not support the use of hydralazine as a first line agent for the treatment of severe hypertension in pregnancy. Compared with other antihypertensives, use of hydralazine was associated with more cesarean sections, placental abruption, maternal oliguria, and maternal side effects such as headache, palpitations, hypotension, and tachycardia.

Hydralazine is excreted into human milk. Adverse effects in the nursing infant are unlikely. The American Academy of Pediatrics considers hydralazine to be compatible with breast-feeding; however, some experts recommend against breast-feeding during hydralazine therapy.

In one case report of a woman who was taking hydralazine 50 mg three times a day, the milk to maternal serum concentration ratio was 1.4, indicating concentration of hydralazine in milk. Even so, the amount of drug exposed to the nursing infant is relatively small, and no adverse effects in the nursing infant were observed.

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Who should NOT use this medication?

• CAD.
• Mitral valvular rheumatic heart disease.
• Hypersensitivity to hydralazine hydrochloride or any ingredient in the formulation.

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What happens if I overdose?
Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include headache, dizziness, fast heart rate, warmth or tingling under your skin, chest pain, or fainting.

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What should I discuss with my healthcare provider before taking hydralazine?
You should not use this medication if you are allergic to hydralazine, or if you have: coronary artery disease; or rheumatic heart disease affecting the mitral valve. Before taking hydralazine, tell your doctor if you are allergic to any drugs, or if you have: kidney disease, lupus; angina pectoris (chest pain); or if you have ever had stroke. If you have any of these conditions, you may need a dose adjustment or special tests to safely take this medication. FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

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Can I stop taking the medication if I feel better?
Even though you may feel better you should not stop taking your high blood pressure medication without first checking with your healthcare provider.

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I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.

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Where can I get more information?
More Information

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