- High Blood Pressure Slideshow Pictures
- Take the Salt Quiz!
- Lowering Blood Pressure Exercise Tips Pictures
- What is labetalol, and how does it work (mechanism of action)?
- What brand names are available for labetalol?
- Is labetalol available as a generic drug?
- Do I need a prescription for labetalol?
- What are the side effects of labetalol?
- What is the dosage for labetalol?
- Which drugs or supplements interact with labetalol?
- Is labetalol safe to take if I'm pregnant or breastfeeding?
- What else should I know about labetalol?
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 1984.
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:
Quick GuideHow to Lower Blood Pressure: Exercise Tips
What is the dosage for labetalol?
The recommended starting oral dose of labetalol is 100 mg twice daily and the dose can be increased by 100 mg twice daily every 2-3 days based on the response of the blood pressure. Usual maintenance doses are 200-400 mg twice daily. Patients with severely high blood pressure may require 1.2 to 2.4 g daily.
Side effects may be less if labetalol is given in three daily doses rather than two. Stopping or changing the dose of the drug should be directed by a physician because serious side effects may occur. The initial intravenous dose of labetalol is 20 mg injected over 2 minutes. Additional injections of 40 or 80 mg may be administered every 10 minutes as needed up to a total dose of 300 mg. Labetalol also may be administered by intravenous infusion at 1-2 mg/minute.
Which drugs or supplements interact with labetalol?
Labetalol can mask early warning symptoms of hypoglycemia (low blood sugar) such as tremors and increased heart rate which are the result of activation of the adrenergic nervous system. Therefore, people with diabetes taking medications that lower blood sugar such as insulin or oral antidiabetic medications may need to increase the frequency with which they monitor their blood sugar in order to prevent hypoglycemia.
Combining labetalol with tricyclic antidepressants such as amitriptyline (Elavil, Endep), imipramine (Tofranil), or nortriptyline (Pamelor) may lead to an increase in tremor which is a side effect of tricyclic antidepressants.
If combined with adrenergic stimulating drugs used for treating asthma, for example, albuterol (Proventil, Ventolin) or pirbuterol (Maxair), the adrenergic blocking effects of labetalol may counteract the effects of the stimulating drugs and reduce their effectiveness for treating asthmatic attacks. More of the adrenergic drug may be needed.
Glutethimide (Doriden) may decrease the effectiveness of labetalol by increasing its elimination. When both drugs are used together, more labetalol or less glutethimide may be needed.
Cimetidine (Tagamet) may increase the effectiveness of labetalol by blocking its elimination and increasing its levels in the blood. Therefore, less labetalol may be needed when cimetidine and labetalol are used together.
Halothane anesthesia may contribute to the blood pressure lowering effects of labetalol.
Is labetalol safe to take if I'm pregnant or breastfeeding?
There are no adequate studies of labetalol during pregnancy.
Labetalol is excreted in human breast milk. Therefore, it should be used cautiously in nursing mothers because of the risk that the infant may develop a slow heart rate.
What else should I know about labetalol?
How should I keep labetalol stored?
Tablets should be stored between 20 C - 30 C (36 F - 86 F).
Multimedia: Slideshows, Images & Quizzes
Picture of Hypertension
High blood pressure, defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140...
Heart Disease: Symptoms, Signs, and Causes
What is heart disease (coronary artery disease)? Learn about the causes of heart disease. Symptoms of heart disease include chest...
Heart Disease: Causes of a Heart Attack
Learn about heart disease and heart attack symptoms and signs of a heart attack in men and women. Read about heart disease...
Related Disease Conditions
High Blood Pressure (Hypertension) Signs, Causes, Diet, and Treatment
High blood pressure (hypertension) is a disease in which pressure within the arteries of the body is elevated. About 75 million...
High Blood Pressure Treatment (Natural Home Remedies, Diet, Medications)
High blood pressure (hypertension) means high pressure (tension) in the arteries. Treatment for high blood pressure include...
Heart disease (coronary artery disease) occurs when plaque builds up in the coronary arteries, the vessels that supply blood to...
Aortic dissection is a small tear in the large blood vessel that leads from the heart and supplies blood to the body. There are...
Treatment & Diagnosis
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Generic Drugs, Are They as Good as Brand-Names?
- Drugs: Buying Prescription Drugs Online Safely
- Drugs: The Most Common Medication Errors
- Medication Disposal - What to Do with Old or Unusable Medication
- Dangers of Mixing Medications
Medications & Supplements
Prevention & Wellness
Daily Health News
Heart Health Resources
Subscribe to MedicineNet's Heart Health Newsletter
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
FDA Prescribing Information
Top labetalol Related Articles
Aortic DissectionAortic dissection is a small tear in the large blood vessel that leads from the heart and supplies blood to the body. There are two types of aortic dissection, type 1 and type 2. Signs and symptoms of aortic dissection include a tearing or ripping pain, nausea, sweating, weakness, shortness of breath, sweating, or fainting. Treatment depends on the type of aortic dissection, and the severity of the tear in the aorta.
atenololAtenolol (Tenormin)is a beta-adrenergic blocking agent, blocking the action of the sympathetic nervous system, a portion of the involuntary nervous system. Atenolol is prescribed for patients with high blood pressure (hypertension), used to treat chest pain (angina pectoris) related to coronary artery disease, and is also useful in slowing and regulating certain types of abnormally rapid heart rates (tachycardias). Other uses for atenolol include the prevention of migraine headaches and the treatment of certain types of tremors (familial or hereditary essential tremors). It is important to be aware of the drug interactions related to atenolol, effects on pregnancy, as well as common side effects on the user.
carvedilolCarvedilol (Coreg, Coreg CR) drug prescribed to control high blood pressure in addition to a diuretic. Carvedilol also may be prescribed in addition with other drugs to manage mild to moderate congestive heart failure and heart disease for patients who have suffered a recent heart attack. Side effects, drug interactions, dosage, storage, and pregnancy safety information should be reviewed prior to taking this medication.
Drug InteractionsDrug interactions occur frequently. Get facts about the types of drug interactions, what substances or other things that may interact with drugs such as OTC drug and prescription drugs, vitamins, food(s) (grapefruit), and laboratory tests. Find out how to protect yourself from potential drug interactions.
Drugs: What You Should Know About Your DrugsImportant information about your drugs should be reviewed prior to taking any prescription drug. Side effects, drug interactions, warnings and precauctions, dosage, what the drug is used for, what to do if you miss a dose, how the drug is to be stored, and generic vs. brand names.
Heart Disease (Coronary Artery Disease)
Heart disease (coronary artery disease) occurs when plaque builds up in the coronary arteries, the vessels that supply blood to the heart. Heart disease can lead to heart attack. Risk factors for heart disease include:
- High blood pressure
- High cholesterol
- Family history
Angina, shortness of breath, and sweating are just a few symptoms that may indicate a heart attack. Treatment of heart disease involves control of heart disease risk factors through lifestyle changes, medications, and/or stenting or bypass surgery. Heart disease can be prevented by controlling heart disease risk factors.
CAD SlideshowWhat is heart disease (coronary artery disease)? Learn about the causes of heart disease. Symptoms of heart disease include chest pain and shortness of breath. Explore heart disease diagnosis, treatment, and prevention.
Heart Disease SlideshowLearn about heart disease and heart attack symptoms and signs of a heart attack in men and women. Read about heart disease diagnostic tests, treatments, and prevention strategies.
High Blood Pressure Hypertension
High blood pressure (hypertension) is a disease in which pressure within the arteries of the body is elevated. About 75 million people in the US have hypertension (1 in 3 adults), and only half of them are able to manage it. Many people do not know that they have high blood pressure because it often has no has no warning signs or symptoms.
Systolic and diastolic are the two readings in which blood pressure is measured. The American College of Cardiology released new guidelines for high blood pressure in 2017. The guidelines now state that blood normal blood pressure is 120/80 mmHg. If either one of those numbers is higher, you have high blood pressure.
The American Academy of Cardiology defines high blood pressure slightly differently. The AAC considers 130/80 mm Hg. or greater (either number) stage 1 hypertension. Stage 2 hypertension is considered 140/90 mm Hg. or greater.
If you have high blood pressure you are at risk of developing life threatening diseases like stroke and heart attack.
REFERENCE: CDC. High Blood Pressure. Updated: Nov 13, 2017.
High Blood Pressure Medication
High blood pressure (hypertension) medications include drugs from a variety of different drug classes and types.
- ACE inhibitors
- ARB (angiotensin receptor blockers)
- Beta blockers
- Calcium channel blockers (CCBs)
- Alpha-beta blockers
Clonidine (Catapres) and minoxidil also are drugs prescribed for the treatment of high blood pressure. Side effects, warnings and precautions, safety information, and pregnancy and breastfeeding safety information should be reviewed prior to taking any medication.
High Blood Pressure TreatmentHigh blood pressure (hypertension) means high pressure (tension) in the arteries. Treatment for high blood pressure include lifestyle modifications (alcohol, smoking, coffee, salt, diet, exercise), drugs and medications such as ACE inhibitors, angiotensin receptor blockers, beta blockers, diuretics, calcium channel blockers (CCBs), alpha blockers, clonidine, minoxidil, and Exforge.
Hypertension PictureHigh blood pressure, defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90. See a picture of Hypertension and learn more about the health topic.
ParathyroidectomyParathyroidectomy is the removal of one or more of the parathyroid glands to treat hyperparathyroidism. Risks of parathyroidectomy include:
- paralysis of the vocal cords,
- difficulty swallowing thin liquids,
- difficulty breathing,
- and drug reactions.
- damage to the recurrent laryngeal nerve,
- bleeding or hematoma,
- problems maintaining calcium levels in the blood,
- need for further and more aggressive surgery,
- need for a limited or total thyroidectomy,
- prolonged pain,
- impaired healing,
- and recurrence of the tumor.
Side Effects and Adverse Effects of Beta Blockers
Beta blockers (beta-adrenergic blocking agents) is a class of drugs that block norepinephrine and adrenaline from binding to beta receptors on nerves. Beta blockers inhibit (block) these two hormones, thereby reducing heart rate and blood vessels. There are a variety of drugs in this class, for example, atenolol (Tenormin), carvedilol (Coreg), and metoprolol (Lopressor, Toprol XL).
Common side effects of these drugs include:
- Stomach cramps
Other important side effects include:
- Blurred vision
- Hair Loss
These drugs also cause central nervous system (CNS) effects like:
Other serious side effects of beta-blockers include:
- Lupus erythematous
- Serious allergic reactions
- Erythema multiform
- Steven Johnson Syndrome
- Toxic epidermal necrolysis