Labetalol Side Effects

Medically reviewed by Drugs.com. Last updated on Feb 10, 2024.

Applies to labetalol: intravenous solution.

Other dosage forms:

• oral tablet

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood and urine tests will be needed to check for unwanted effects.

You should not receive this medicine together with verapamil (Calan®).

Dizziness, lightheadedness, or fainting may occur, especially when you get up suddenly from a lying or sitting position. These symptoms are more likely to occur when you begin using this medicine, or when the dose is increased. Getting up slowly may help.

This medicine may cause heart failure in some patients. Check with your doctor right away if you are having chest pain or discomfort, dilated neck veins, extreme fatigue, irregular breathing, an irregular heartbeat, swelling of the face, fingers, feet, or lower legs, or weight gain.

This medicine may cause changes in your blood sugar levels. Also, this medicine may cover up signs of low blood sugar in patients who have diabetes or are fasting (eg, surgery, not eating regularly, vomiting), such as a rapid pulse rate. Check with your doctor if you have these problems or if you notice a change in the results of your blood or urine sugar tests.

Check with your doctor right away if you or your child have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

If you plan to have cataract surgery, tell your eye doctor (ophthalmologist) that you are receiving this medicine or that you received this medicine. A serious eye problem called Intraoperative Floppy Iris Syndrome (IFIS) has occurred in some patients who were taking this medicine or who had recently taken this medicine when they had cataract surgery.

Make sure any doctor or dentist who treats you knows that you are receiving this medicine. This medicine may affect the results of certain tests.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of labetalol

Along with its needed effects, labetalol may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking labetalol:

Get emergency help immediately if any of the following symptoms of overdose occur while taking labetalol:

Symptoms of overdose

• dilated neck veins
• extreme fatigue
• irregular breathing
• loss of bladder control
• muscle spasm or jerking of all extremities
• noisy breathing
• seizures
• sudden loss of consciousness
• weight gain

Other side effects of labetalol

Some side effects of labetalol may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

See also:

For healthcare professionals

Applies to labetalol: compounding powder, intravenous solution, oral tablet.

Cardiovascular adverse events

• Common (1% to 10%): Edema, postural hypotension
• Frequency not reported: Bradycardia, heart block, heart failure, hypotension, ankle edema, increase of an existing intermittent claudication, postural hypotension, cold or cyanotic extremities, Raynaud's phenomenon, paresthesia of the extremities, syncope^[Ref]

Dermatologic

• Uncommon (0.1% to 1%): Increased sweating
• Frequency not reported: Systemic lupus erythematosus, rashes (e.g., generalized maculopapular, lichenoid, urticarial, bullous lichen planus, psoriaform, facial erythema, Peyronie's disease, reversible alopecia)^[Ref]

Endocrine

• Frequency not reported: Masking of the normal response to hypoglycemia (sweating and tachycardia); this may be important in some patients with diabetes mellitus^[Ref]

Gastrointestinal

• Common (1% to 10%): Nausea, dyspepsia, vomiting
• Uncommon (0.1% to 1%): Diarrhea
• Frequency not reported: Epigastric pain^[Ref]

Genitourinary

• Common (1% to 10%): Ejaculation failure, impotence
• Frequency not reported: Difficulty in micturition (including acute urinary bladder retention)^[Ref]

Hepatic

• Common (1% to 10%): Transient elevations of liver function tests
• Frequency not reported: Hepatic necrosis, hepatitis, cholestatic jaundice^[Ref]

Hypersensitivity

• Rare (less than 0.1%): Hypersensitivity (e.g., rash, urticaria, pruritus, angioedema, dyspnea), anaphylactoid reactions^[Ref]

Immunologic

• Frequency not reported: Antimitochondrial antibodies^[Ref]

Metabolic

• Very rare (less than 0.01%): Hyperkalemia^[Ref]

Musculoskeletal

• Frequency not reported: Muscle cramps, toxic myopathy^[Ref]

Nervous system

• Very common (10% or more): Dizziness (11%)
• Common (1% to 10%): Headache, taste distortion, vertigo, paresthesia, scalp tingling
• Uncommon (0.1% to 1%): Drowsiness
• Frequency not reported: Tremor^[Ref]

Ocular

• Common (1% to 10%): Vision abnormality
• Frequency not reported: Dry eyes
• Postmarketing reports: Intraoperative Floppy Iris Syndrome (IFIS) observed during cataract surgery^[Ref]

Respiratory

• Common (1% to 10%): Nasal stuffiness, dyspnea
• Frequency not reported: Bronchospasm, interstitial lung disease^[Ref]

Other

• Common (1% to 10%): Fatigue, asthenia
• Frequency not reported: Positive antinuclear factor^[Ref]

Psychiatric

• Frequency not reported: Depressed mood and lethargy, hallucinations, psychoses, confusion, sleep disturbances, nightmares^[Ref]

Further information

Labetalol side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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