hydrochlorothiazide and hydralazine

Generic name: hydrochlorothiazide and hydralazine [ HYE-droe-KLOR-oh-THYE-a-zide-and-hye-DRAL-a-zeen ]
Brand names: Hydra-Zide, Apresazide, HydrALAZINE Plus
Drug class: Miscellaneous antihypertensive combinations

What is hydrochlorothiazide and hydralazine?

Hydrochlorothiazide is a thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention.

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.

The combination of hydrochlorothiazide and hydralazine is used to treat high blood pressure (hypertension).

Hydrochlorothiazide and hydralazine is usually given after other blood pressure medications have been tried without successful treatment.

Hydrochlorothiazide and hydralazine may also be used for purposes not listed in this medication guide.

What is the most important information I should know about hydrochlorothiazide and hydralazine?

You should not use this medication if you are allergic to hydralazine (Apresoline) or hydrochlorothiazide, or if you have coronary artery disease, rheumatic heart disease affecting the mitral valve, or if you are unable to urinate.

Before using this medication, tell your doctor if you have liver disease, kidney disease, glaucoma, angina pectoris (chest pain), asthma or allergies, gout, lupus, diabetes, an allergy to sulfa drugs or penicillin, or if you have ever had a stroke.

Drinking alcohol can further lower your blood pressure and may increase certain side effects of hydrochlorothiazide and hydralazine.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

There are many other drugs that can interact with hydrochlorothiazide and hydralazine. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor. Keep a list of all your medicines and show it to any healthcare provider who treats you.

Keep using this medicine as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

What should I discuss with my doctor before taking hydrochlorothiazide and hydralazine?

You should not use this medication if you are allergic to hydralazine (Apresoline) or hydrochlorothiazide, or if you have:

• coronary artery disease;

• rheumatic heart disease affecting the mitral valve; or

• if you are unable to urinate.

To make sure you can safely take hydrochlorothiazide and hydralazine, tell your doctor if you have any of these other conditions:

• kidney disease;

• liver disease;

• glaucoma;

• angina pectoris (chest pain);

• asthma or allergies;

• gout;

• lupus;

• diabetes;

• an allergy to sulfa drugs or penicillin; or

• if you have ever had stroke.

FDA pregnancy category C. It is not known whether hydrochlorothiazide and hydralazine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

It is not known whether hydrochlorothiazide and hydralazine passes into breast milk or if it could harm a nursing baby. You should not breast-feed while you are using hydrochlorothiazide and hydralazine.

How should I take hydrochlorothiazide and hydralazine?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results.

Conditions that may cause very low blood pressure include: vomiting, diarrhea, heavy sweating, heart disease, dialysis, a low salt diet, or taking diuretics (water pills). Tell your doctor if you have a prolonged illness that causes diarrhea or vomiting.

Your blood pressure will need to be checked often. Your blood and urine may both be tested if you have been vomiting or are dehydrated. Visit your doctor regularly.

If you need surgery or medical tests, tell the doctor ahead of time that you are taking medication that contains hydrochlorothiazide. You may need to stop using the medicine for a short time.

Keep using this medicine as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include headache, thirst, fast heart rate, nausea, vomiting, weakness, dizziness, feeling like you might pass out, leg pain, numbness or tingling, and urinating less than usual or not at all.

What should I avoid while taking hydrochlorothiazide and hydralazine?

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

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.

Drinking alcohol can further lower your blood pressure and may increase certain side effects of hydrochlorothiazide and hydralazine.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

Hydrochlorothiazide and hydralazine side effects

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.

Stop using this medication and call your doctor at once if you have a serious side effect such as:

• eye pain, vision problems;

• dry mouth, thirst, nausea, vomiting;

• feeling weak, drowsy, restless, or light-headed;

• fast or uneven heart rate;

• muscle pain or weakness;

• confusion, unusual thoughts or behavior;

• pale skin, easy bruising or bleeding;

• painful or difficult urination;

• urinating less than usual or not at all;

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

• numbness, burning, pain, or tingly feeling;

• a red, blistering, peeling skin rash;

• dark-colored urine, jaundice (yellowing of the skin or eyes); or

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

Less serious side effects may include:

• loss of appetite, diarrhea, constipation;

• headache;

• dizziness, spinning sensation;

• blurred vision;

• muscle or joint pain; or

• mild itching or skin rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

Hydrochlorothiazide and hydralazine dosing information

Usual Adult Dose for Congestive Heart Failure:

Initial dose: 1 capsule orally twice a day (the strength depending upon individual requirement following titration).

Maintenance dose: Should be adjusted to the lowest effective level. Higher daily HCTZ doses are not recommended. Daily hydralazine doses up to 200 mg can be given and are safe for use in most patients. Hydralazine doses up to 300 mg per day (75 mg four times a day) were used in the first Veterans Heart Failure Trial demonstrating a reduction of mortality when used in combination with nitrates in patients with chronic congestive heart failure.

While most patients respond to 200 mg of hydralazine per day or less, some "fast acetylators", are resistant, requiring 300 mg per day or more. Because up to 20% of patients who receive 400 mg per day or more develop a systemic lupus erythematosus syndrome, some experts recommend checking a patient's acetylator status before giving higher doses. Up to 70% of "resistant" patients are fast acetylators, in whom the dose can be relatively safely increased.

Usual Adult Dose for Hypertension:

Initial dose: 1 capsule orally twice a day (the strength depending upon individual requirement following titration).

Maintenance dose: Should be adjusted to the lowest effective level. Higher daily HCTZ doses are not recommended. Daily hydralazine doses up to 200 mg can be given and are safe for use in most patients. Hydralazine doses up to 300 mg per day (75 mg four times a day) were used in the first Veterans Heart Failure Trial demonstrating a reduction of mortality when used in combination with nitrates in patients with chronic congestive heart failure.

While most patients respond to 200 mg of hydralazine per day or less, some "fast acetylators", are resistant, requiring 300 mg per day or more. Because up to 20% of patients who receive 400 mg per day or more develop a systemic lupus erythematosus syndrome, some experts recommend checking a patient's acetylator status before giving higher doses. Up to 70% of "resistant" patients are fast acetylators, in whom the dose can be relatively safely increased.

What other drugs will affect hydrochlorothiazide and hydralazine?

Tell your doctor about all other medicines you use, especially:

• lithium (Eskalith, LithoBid);

• diazoxide (Hyperstat, Proglycem);

• digoxin (Lanoxin);

• insulin or oral diabetes medication;

• steroids (prednisone and others);

• other blood pressure medications;

• an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate); or

• aspirin or other NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen (Advil, Motrin), naproxen (Aleve, Naprosyn, Naprelan, Treximet), celecoxib (Celebrex), diclofenac (Arthrotec, Cambia, Cataflam, Voltaren, Flector Patch, Pennsaid, Solareze), indomethacin (Indocin), meloxicam (Mobic), and others.

This list is not complete and other drugs may interact with hydrochlorothiazide and hydralazine. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

Copyright 1996-2025 Cerner Multum, Inc. Version: 6.02. Revision Date: 2012-03-12, 11:27:44 AM.