Hydralazine (patient information)
Why this medication is prescribed
Hydralazine is used to treat high blood pressure. It works by relaxing the blood vessels so that blood can flow more easily through the body.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
How this medication should be used
Hydralazine comes as a tablet to take by mouth. It usually is taken two to four a day at evenly spaced intervals. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take hydralazine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Hydralazine controls high blood pressure but does not cure it. Continue to take hydralazine even if you feel well. Do not stop taking hydralazine without talking to your doctor.
Other uses for this medicine
Hydralazine is also used after heart valve replacement and in the treatment of congestive heart failure. Talk to your doctor about the possible risks of using this drug for your condition.
Special precautions
Before taking hydralazine:
- tell your doctor and pharmacist if you are allergic to hydralazine, aspirin, tartrazine (a yellow dye in some processed foods and medications), or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially indomethacin (Indocin), metoprolol (Lopressor), propranolol (Inderal), and vitamins.
- tell your doctor if you have or have ever had coronary artery disease, rheumatic heart disease, kidney or liver disease, or a heart attack.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking hydralazine, call your doctor.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking hydralazine.
- ask your doctor about the safe use of alcohol while you are taking hydralazine. Alcohol can make the side effects from hydralazine worse.
Special dietary instructions
Take hydralazine with meals or a snack.
Your doctor may prescribe a low-salt or low-sodium diet. Follow these directions carefully.
What to do if you forget a dose
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Side Effects
Minor Side Effects
Hydralazine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- flushing (feeling of warmth)
- headache
- upset stomach
- vomiting
- loss of appetite
- diarrhea
- constipation
- eye tearing
- stuffy nose
- rash
Severe Side Effects
If you experience any of the following symptoms, call your doctor immediately:
- fainting
- joint or muscle pain
- unexplained fever
- rapid heartbeat
- chest pain
- swollen ankles or feet
- numbing or tingling in hands or feet
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].
Storage conditions needed for this medication
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Other information
Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly to determine your response to hydralazine.
Your doctor may ask you to check your blood pressure daily. Ask your doctor or pharmacist to teach you how.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
Brand names of combination products
- Hydra-Zide® (containing Hydralazine Hydrochloride and Hydrochlorothiazide)