Medically reviewed by Jessica Swirble, PharmD
Last updated on 5/3/2024

Drug Information | Side Effects | Use & Dosage | Request a Prescription

The use of hydralazine can lead to various side effects in some individuals.

Common mild side effects of hydralazine use include:

• Headache
  
• Dizziness or lightheadedness
  
• Nausea or upset stomach
  
• Vomiting
  
• Diarrhea or constipation
  
• Loss of appetite
  
• Nasal congestion
  
• Palpitations (feeling your heart beat rapidly or irregularly)
  
• Flushing or warmth of the face
  
  

More severe side effects of hydralazine use can include:

• Rapid heartbeat or chest pain
  
• Severe allergic reactions (such as rash, itching, swelling of the face, tongue, or throat, trouble breathing)
  
• Joint or muscle pain
  
• Fluid retention or swelling
  
• Severe weakness
  
• Fever
  
• Numbness or tingling in the hands or feet
  
• Difficulty breathing
  
• Signs of a new infection (such as sore throat that doesn't go away, fever)
  
• Unusual bleeding or bruising
  
• Mood changes, such as depression or anxiety
  
  

If you experience any severe or concerning side effects while taking hydralazine, contact your healthcare provider right away.

Tell your healthcare provider about any existing medical conditions, allergies, or other medications you are taking before starting treatment with hydralazine. This includes prescription drugs, over-the-counter medications, and dietary supplements, as they may interact with hydralazine.

Tell your provider if you are taking these medications or supplements:

• Blood pressure medications (especially for high blood pressure)
  
• Medications that increase heart rate
  
• Non-steroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen and aspirin)
  
• Over-the-counter (OTC) cold medications
  
• Any drugs or supplements that cause flushing or increased heart rate
  
  

You should also mention medical conditions such as:

• Kidney disease
  
• Heart conditions or heart disease (such as coronary artery disease and heart failure)
  
• Previous stroke or heart attack
  
• Lupus or other autoimmune diseases
  
  

If you are pregnant, planning to become pregnant, or breastfeeding, consult your healthcare provider before using hydralazine to assess potential risks and benefits.

Take hydralazine exactly as prescribed by your healthcare provider. Do not exceed the recommended dose or duration of treatment.

Hydralazine should be taken with or without food based on your healthcare provider's advice. It should either be taken consistently with food or taken consistently without food to ensure consistent absorption. It is important to follow their instructions for optimal effectiveness.

Avoid alcohol and activities that require alertness until you understand how hydralazine affects you, as it can cause dizziness.

Store hydralazine at room temperature, away from moisture and heat. Keep it out of reach of children.

In case of a hydralazine overdose, seek medical attention immediately. Symptoms of overdose may include severe headache, rapid heartbeat, severe dizziness, cold or clammy skin, and fainting. If you suspect an overdose, contact the poison control helpline at 1-800-222-1222 or call emergency services.