Medically reviewed by Drugs.com. Last updated on Sep 6, 2022.
Commonly used brand name(s)
In the U.S.
- Novaplus HydrALAZINE Hydrochloride
Available Dosage Forms:
Therapeutic Class: Peripheral Vasodilator
Uses for hydralazine
Hydralazine injection is used to treat high blood pressure (hypertension). High blood pressure adds to the workload of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure. Lowering blood pressure can decrease the risk of heart attacks and strokes.
Hydralazine works by relaxing the blood vessels and increasing the supply of blood and oxygen to the heart while reducing its workload.
Hydralazine is to be given only by or under the direct supervision of your doctor.
Before using hydralazine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For hydralazine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to hydralazine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies on the relationship of age to the effects of hydralazine injection have not been performed in the pediatric population. However, no pediatric-specific problems have been documented to date.
No information is available on the relationship of age to the effects of hydralazine injection in geriatric patients.
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using hydralazine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use hydralazine, or give you special instructions about the use of food, alcohol, or tobacco.
- Enteral Nutrition
Other medical problems
The presence of other medical problems may affect the use of hydralazine. Make sure you tell your doctor if you have any other medical problems, especially:
- Angina (severe chest pain) or
- Blood disease or
- Heart attack, history of or
- Heart rhythm problems or
- Hypotension (low blood pressure) or
- Peripheral neuritis (nerve problem) or
- Stroke, history of or
- Systemic lupus erythematosus—Use with caution. May make these conditions worse.
- Coronary artery disease or
- Mitral valvular rheumatic heart disease—Should not be used in patients with these conditions.
- Kidney disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper use of hydralazine
A nurse or other trained health professional will give you hydralazine in a hospital. Hydralazine is given through a needle placed in one of your veins.
Your doctor will give you a few doses of hydralazine until your condition improves, and then switch you to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor.
Precautions while using hydralazine
It is important that your doctor check you closely while you are receiving hydralazine. This will allow your doctor to see if the medicine is working properly. Blood tests may be needed to check for unwanted effects.
Hydralazine may cause some people to have headaches or to feel dizzy. Make sure you know how you react to hydralazine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.
Do not take other medicines unless they have been discussed with your doctor. This especially includes over-the-counter (nonprescription) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.
Hydralazine side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor or nurse immediately if any of the following side effects occur:
- Am, back, or jaw pain
- chest pain or discomfort
- chest tightness or heaviness
- fast, pounding, or irregular heartbeat or pulse
- shortness of breath
- Black, tarry stools
- blindness or vision changes
- blurred vision
- burning of the face or mouth
- burning, crawling, itching, numbness, painful, prickling, "pins and needles", or tingling feelings
- clumsiness or unsteadiness
- difficult or labored breathing
- dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
- fever and sore throat
- lower back or side pain
- painful or difficult urination
- pale skin
- shakiness in the legs, arms, hands, feet
- swollen, painful, or tender lymph glands in the neck, armpit, or groin
- trembling or shaking of the hands or feet
- ulcers, sores, or white spots in the mouth
- unusual bleeding or bruising
- unusual tiredness or weakness
- weakness in the hands or feet
- Dark urine
- general tiredness and weakness
- light-colored stools
- nausea and vomiting
- upper right abdominal or stomach pain
- yellow eyes and skin
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- Feeling of warmth
- redness of the face, neck, arms, and occasionally, upper chest
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- loss of appetite
- weight loss
- Difficulty having a bowel movement (stool)
- difficulty with moving
- feeling anxious or depressed
- muscle cramps, pain, or stiffness
- pain in the joints
- rash, hives or welts, itching
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about hydralazine
- Check interactions
- Pricing & coupons
- Reviews (83)
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- Side effects
- Dosage information
- Patient tips
- During pregnancy
- Drug class: vasodilators
- En español
- Drug Information
- Hydralazine Oral, Injection, Intravenous (Advanced Reading)
- Hydralazine Tablets
- Hydralazine Injection
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