What Is Labetalol?

Labetalol is a medication that belongs to the group of drugs known as beta blockers. It is most often used to treat high blood pressure, but may sometimes be prescribed to those suffering from angina, or chest pain, and tetanus. This drug is said to work by slowing the heart rate and relaxing the blood vessels to help increase blood flow while decreasing blood pressure. Although this medication is often used on its own to treat less severe cases of hypertension, it may also sometimes be paired with other blood pressure medications.

High blood pressure, or hypertension, is said to increase the burden of the arteries and heart, which, over time, can lead to a decrease in the functioning of these vital structures and may result in damage to the heart, liver, kidneys, and brain. Labetalol is a blood pressure medication used to help prevent this damage from occurring. It is said to work by blocking the receptors of the adrenergic nervous system.

The adrenergic nervous system contains nerves that travel to several arteries, where they release a chemical known as norepinephrine. When norepinephrine is released, it attaches to receptors on the arterial muscles and causes these muscles to contract and narrow, resulting in an increase of blood pressure. Labetalol is said to attach to and block the receptors, which can result in the relaxation of arterial muscles and expansion of the arteries, thus causing a decrease of blood pressure.

The dosage of labetalol is often dependent on the patient's medical history. Available preparations typically come in 100, 200, or 300 mg tablets, but may also be available in the form of a 5-mg, injectable solution. Patients are generally started on 100 mg twice daily, but this dosage may increase, depending on how the patient responds to the drug.

As with any medication, labetalol may cause some side effects. Some of the most common reactions are often considered mild and short lived, such as upset stomach or headache, dizziness or lightheadedness, fatigue, stuffy nose, and a tingling sensation of the skin and scalp. Though these side effects are often temporary, patients are encouraged to seek medical attention if they become persistent. More severe symptoms may require an immediate visit to the doctor. These side effects can include a rapid increase in weight gain, swelling of the lower extremities, chest pain, and shortness of breath.