What is labetalol, and how does it work (mechanism of action)?

Labetalol is a drug that is used for
treating high blood pressure. And is related to carvedilol (Coreg). Nerves from
the adrenergic nervous system travel from the spinal cord to arteries where they
release norepinephrine. Norepinephrine attaches to adrenergic receptors on
arteries and causes the arteries to contract, narrowing the arteries, and
increasing blood pressure. Labetalol blocks receptors of the adrenergic nervous
system. When labetalol attaches to and blocks the receptors, arteries expand,
resulting in a fall in blood pressure. The FDA approved labetalol in August

What brand names are available for labetalol?

None. Normodyne and Trandate are discontinued.

Is labetalol available as a generic drug?


Do I need a prescription for labetalol?


What are the side effects of labetalol?

The most common side effects of labetalol are:

Postural hypotension (a rapid decrease in blood pressure when going from the lying or seated position to the standing position that may cause light-headedness or fainting) occurs rarely. Patients should be observed for this possible side effect within two to four hours of the first labetalol dose and after any changes in dose.

Other important side effects include:

  • sexual dysfunction,
  • abnormal heart rhythm,
  • slow heart rate,
  • liver failure, and
  • allergic reactions.

Medically Reviewed by a Doctor on 5/11/2017

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