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As is the case with any other medication, there may be instances where hydralazine interactions can occur. In such cases, use is not recommended, or usage will have to be adjusted to prevent or reduce the risk of negative interactions occurring from other drugs, medical conditions, or even food and drink.

Drug Interactions

According to the FDA, drugs that may interact with this medication include the following.

  • Monoamine oxidase inhibitors (MAOIs) should be used with caution
  • There are many other drug interactions not listed here including but not limited to below.

Please note that this list may not be complete, and other interactions with drugs not listed here may occur.

Isosorbide Dinitrate

Isosorbide dinitrate and hydralazine are sometimes combined into the single brand name medication Bidil. Hydralazine is a vasodilator, and isosorbide dinitrate is a nitrate; together, they make a great blood pressure-lowering team. A vasodilator relaxes blood vessels to make blood easier to pump, reducing stress on the heart. A nitrate additionally widens blood vessels to provide better blood flow.


Amlodipine (Norvasc) is a calcium-channel blocker also used to treat hypertension, or high blood pressure. Experts do not report major interactions between amlodipine and hydralazine.

However, there may be an interaction between amlodipine and a medication that combines hydralazine and hydrochlorothiazide (Apresazide). Considering this drug is currently discontinued in the United States, though, this interaction is not clinically relevant. 


Hydralazine and nitrates are sometimes combined in the treatment of conditions like congestive heart failure. A vasodilator relaxes the blood vessels, allowing blood to pump more freely. A nitrate widens them to improve blood flow. 


There may be a minor interaction between these two drugs. Carvedilol (Coreg) is a beta blocker, a type of medication that blocks effects of epinephrine (adrenaline). Experts believe these actions reduce blood pressure while also relaxing blood vessels and improving blood flow. 

Vasodilators like hydralazine may increase serum renin levels of beta blockers. In other words, hydralazine may increase levels of beta blockers like carvedilol in plasma. That said, experts typically do not consider this interaction to be clinically significant. 


Anyone on hydralazine should talk to their medical provider or pharmacist before taking nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil) or naproxen (Aleve). These medications can increase blood pressure and heart rate, which could potentially mitigate the anti-hypertensive effects of hydralazine. 


Atenolol (Tenormin) is a beta-blocker, and hydralazine is a vasodilator. These two classes of medication are sometimes combined to provide the best therapeutic options for serious heart conditions like congestive heart failure (CHF). 


Taking a beta blocker like labetalol (Normodyne) with a vasodilator like hydralazine might intensify the effects of these drugs, causing blood pressure to drop too low (hypotension). 


Tizanidine (Zanaflex) is used to treat muscle spasticity for spinal cord injury or a degenerative neurological disease, such as multiple sclerosis (MS). Combining this drug with hydralazine might affect the heart rhythm. 


Taking Apresazide (hydralazine and hydrochlorothiazide) plus hydralazine can cause a drop in potassium levels. A medical provider would potentially add a potassium supplement to counteract that effect, although Apresazide is currently discontinued in the United States. People should not take potassium without the recommendation of a medical professional, though. 


Alprazolam (Xanax) is a short-acting tranquilizer. It may interact with hydralazine plus Apresazide and further lower blood pressure. 

Food Interactions

Sometimes the foods we eat and the beverages we drink can also interact with our medications. According to the FDA, food and drink that may interact with this drug include:

Please note that this list may not be complete, and there may be other foods and beverages that interact with this drug.

Hydralazine and Alcohol

For more information, please visit our page on hydralazine and alcohol interactions. 

Disease & Conditions Interactions

Sometimes certain medications can increase the risk of negative side effects for certain diseases or other medical conditions. According to the FDA, diseases, and medical conditions that are known to negatively interact with hydralazine include:

  • Coronary artery disease
  • Mitral valvular rheumatic heart disease

Please note that this list may not be complete, and there may be other diseases and medical conditions where patients should not take this medication.

Heart Rate

Hydralazine has a vasodilating effect that lowers arterial blood pressure, decreases peripheral vascular resistance, and slows heart rate. For some, it may cause an abnormal heart rhythm like tachycardia (fast heartbeat).


Some people experience symptoms that look much like systemic lupus erythematosus when they take hydralazine. 

These symptoms could include:

  • joint pain and stiffness
  • a rash on your face
  • fever
  • tiredness
  • loss of appetite
  • nausea
  • kidney problems
  • weight loss
  • chest pain

If these symptoms occur, a medical provider may decide to discontinue the medication. Approximately 8 percent of people taking hydralazine may develop drug-induced lupus. 

Hydralazine and Pregnancy

For more information, please visit our page on hydralazine and pregnancy risks.

Apresoline and Breastfeeding

For more information, please visit our page on hydralazine and pregnancy risks.


Bradycardia is a slower-than-normal heart rate. The purpose of hydralazine is to lower blood pressure, causing a slow heart rate as a side effect. 


Giving hydralazine to someone after a stroke could worsen brain function. As such, doing so may not be recommended.

BP (Blood Pressure)

Hydralazine is a drug given to lower blood pressure. It relaxes the arteries, so the heart doesn’t have to work as hard to pump blood. However, in some cases, patients may experience hypotension, which is when blood pressure drops too low. In such cases, patients and their medical providers will need to discuss options for bringing blood pressure up in a healthy manner.


In some cases, medical providers may add supplemental potassium for patients taking hydralazine AND a diuretic such as hydrochlorothiazide or lasix. Taking the drug can lead to a drop in potassium, so the supplement helps bring it back up to a healthier level. 

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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