Labetalol Side Effects
Some side effects of labetalol may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
For the Consumer
Applies to labetalol: oral tablet
Get emergency medical help if you have any of these signs of an allergic reaction while taking labetalol: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have a serious side effect such as:
slow or uneven heartbeats;
feeling like you might pass out;
feeling short of breath, even with mild exertion;
swelling or rapid weight gain; or
nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
Less serious side effects of labetalol may include:
tingly feeling in your scalp;
dizziness, spinning sensation;
mild nausea, upset stomach;
stuffy nose; or
difficulty having an orgasm.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
For Healthcare Professionals
Applies to labetalol: compounding powder, intravenous solution, oral tablet
Many of the most common side effects of labetalol resolve with dosage reduction. Orthostatic hypotension/dizziness is usually mild to moderate, transient, and confined to the first few hours after labetalol administration.
Beta-blockers, such as labetalol, are used with caution in patients with claudication or Raynaud's phenomenon due to inhibition of the normal vascular response to low blood flow states.
Cardiovascular side effects are the most common. Fatigue and dizziness have been reported in 3% and up to 12% of patients, respectively. In patients who are receiving 2,400 mg per day or more, however, the incidence of these side effects climbs to 10% and 16%, respectively. Claudication or Raynaud's phenomenon has been reported in 3% of patients. Labetalol may depress cardiac output in 1% of patients, which may be important in some patients with heart failure. Edema, postural hypotension, and bradycardia have also been reported.
Respiratory side effects from beta-blockers, due to inhibition of normal bronchodilation, may be important in patients with a history of reversible airways disease. Nasal stuffiness occurs in less than 5% of patients, and is thought to be due to the alpha-adrenergic blocking properties of labetalol. Dyspnea has also been reported rarely.
Endocrinologic side effects of labetalol include masking of the normal response to hypoglycemia (sweating and tachycardia). This may be important in some patients with diabetes mellitus.
Gastrointestinal side effects including nausea, vomiting, dyspepsia, abdominal pain, taste distortion and diarrhea have been reported.
Nervous system side effects scalp tingling (7%) have been reported. Headaches, asthenia, paresthesias, fatigue, dizziness, vertigo, drowsiness, nightmares or dreams, tremors, blurry vision, and general weakness are reported in less than 5% of patients.
Hepatic side effects are rare. Transient elevations of liver function tests have been reported in 4% of patients. Cholestatic jaundice and hepatitis have been reported in rare cases. One case of associated hepatitis was fatal.
A 63-year-old woman with hypertension developed diarrhea, dark urine, and nausea associated with elevated liver function tests within 90 days after beginning labetalol. Serology was negative for a viral etiology, and the patient had no blood transfusions, known food exposure, or alcohol use. Her signs and symptoms resolved upon discontinuation of labetalol. Several months later, the drug was reinstated, and the patient, within two months, became anorectic with recurrent signs and symptoms of hepatitis. A complete work-up was unremarkable. The disease progressed to hepatic encephalopathy and death.
In patients with liver disease, frequent monitoring of liver function tests is recommended.
Nonselective beta-blockers may inhibit the Na-K ATPase pump independent of aldosterone or insulin.
Metabolic side effects are extremely rare. There have been at least three case reports of severe hyperkalemia in post renal transplant patients who were given intravenous labetalol.
A 47-year-old woman with hypertension suffered acute generalized erythema, urticaria, pruritus, and angioedema 30 to 60 minutes after receiving her first dose of labetalol 100 mg. During urination, she became markedly hypotensive, which was associated with a pulse of 30 beats per min. She was successfully resuscitated; rechallenge was not undertaken.
Hypersensitivity reactions are rare. A variety of skin rashes, including a maculopapular erythematous rash, urticaria, atypical lichen planus, and bullous lichen planus have been reported in rare cases. A single case each of anaphylaxis and fever associated with labetalol have been reported.
Genitourinary complaints are rare. Urinary retention has been reported in less than 5% of patients, and is believed to be due to the alpha-adrenergic blocking properties of labetalol. Decreased libido, impotence, priapism, ejaculatory failure, and retrograde ejaculation have rarely been reported.
A 45-year-old woman developed polyarthralgias and muscle tenderness without a rash six months after beginning labetalol for hypertension. Associated laboratory findings included a raised ANA. Her signs and symptoms gradually resolved upon substitution with propranolol and institution of indomethacin therapy.
Immunologic reactions associated with labetalol, as with some other beta-blockers, include the development of a positive antinuclear antibody (ANA) titer in approximately 2% of patients. Rare cases of labetalol-induced systemic lupus erythematosus have been reported.
Musculoskeletal pain has been reported in rare cases. In at least one case, serum skeletal muscle enzyme levels were elevated and findings of electromyography and electron microscopy were consistent with drug-induced myositis.
Dermatologic side effects including rash have been reported rarely.
Ocular side effects have included Intraoperative Floppy Iris Syndrome (IFIS) observed during cataract surgery in some patients treated with alpha-1 blockers (such as labetalol).
More labetalol resources
- labetalol Concise Consumer Information (Cerner Multum)
- labetalol MedFacts Consumer Leaflet (Wolters Kluwer)
- labetalol Advanced Consumer (Micromedex) - Includes Dosage Information
- Labetalol Prescribing Information (FDA)
- Labetalol Hydrochloride Monograph (AHFS DI)
- Trandate Prescribing Information (FDA)
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