Reviewed on 10/25/2021

What Is Labetalol and How Does It Work?

Labetalol is a prescription medication used to treat the symptoms of Hypertension (high blood pressure), and Hypertensive Emergency.

  • Labetalol is available under the following different brand names: Trandate

What Are Side Effects Associated with Using Labetalol?

Common side effects of Labetalol include:

  • dizziness, 
  • drowsiness, 
  • tiredness, 
  • nausea, 
  • vomiting, 
  • sudden warmth, 
  • skin redness, 
  • sweating, 
  • numbness, and 
  • tingly feeling in the scalp

Serious side effects of Labetalol include:

  • hives, 
  • difficulty breathing, 
  • swelling of face, lips, tongue, or throat, 
  • severe dizziness, 
  • lightheadedness
  • slow heart rate, 
  • weak pulse
  • fainting
  • slow breathing or breathing that may stop, 
  • shortness of breath (even with mild exertion), 
  • swelling, 
  • rapid weight gain, 
  • severe headache, 
  • blurred vision, 
  • pounding in neck or ears, 
  • loss of appetite, 
  • stomach pain (upper right side), 
  • flu-like symptoms, 
  • itching, 
  • dark urine, and
  • yellowing of the skin or eyes (jaundice)

Rare side effects of Labetalol include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Are Dosages of Labetalol?

Adult and pediatric dosage

Injectable solution

  • 5mg/mL


  • 100mg
  • 200mg
  • 300mg



  • 100 mg orally every 12 hours initially; increased by 100 mg every 12 hours every 2-3 days
  • Usual dose range: 200-400 mg orally every 12 hours; not to exceed 2400 mg/day

Hypertensive Emergency


  • 20 mg IV over 2 minutes initially, then 40-80 mg IV every 10 minutes; total dose not to exceed 300 mg
  • Alternative: 1-2 mg/min by continuous IV infusion; total dose of 300 mg has been used


  • 0.4-1 mg/kg/hr by continuous IV infusion; not to exceed 3 mg/kg/hr

Dosage Considerations – Should be Given as Follows: 

  • See "Dosages."


Salt and sodium are the same. See Answer

What Other Drugs Interact with Labetalol?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them.  Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first

  • Labetalol has severe interactions with the following drug:
  • Labetalol has serious interactions with at least 19 other drugs
  • Labetalol has moderate interactions with at least 168 other drugs.
  • Labetalol has minor interactions with at least 32 other drugs.

This information does not contain all possible interactions or adverse effects.  Visit the RxList Drug Interaction Checker for any drugs interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use.  Keep a list of all your medications with you, and share this information with your doctor and pharmacist.  Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

What Are Warnings and Precautions for Labetalol?


Effects of drug abuse

  • None

Short-Term Effects

  • See “What are Side Effects Associated with Using Labetalol?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Labetalol?”


Pregnancy and Lactation

  • Use with caution if benefits outweigh risks. 
  • Small amounts excreted; use with caution

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