Labetalol is an antihypertensive drug that works by simultaneously blocking two types of receptors, the alpha and beta-adrenergic receptors. It acts by inhibiting the first to the level of the small arteries reducing the resistance to blood passage, while inhibition of beta-receptors reduces the side effects of vasodilation in the heart. Taken together these two actions have the effect of reducing the blood pressure.
What is Labetalol?
Labetalol is used in case of high blood pressure (also during pregnancy) and after a myocardial infarction. It can also be used in case of hypertensive crisis, and to treat hypotension during general anesthesia.
How should Labetalol be taken?
Labetalol assumes the form of tablets in a 100 mg with an initial dose of 2 times a day (morning and evening), always on a full stomach. Subsequently, and if necessary, the dosage may be increased up to 200 mg 2 times a day. However, it is no to be excluded that in particularly resistant cases the condition may require to take even two doses of 400 mg per day. The maximum dose that can be administered is 2.4 grams per day in total.
Side effects associated with Labetalol
The possible side effects of labetalol may include:
- Changes in blood composition
- Angioedema
- Asthenia
- Elevations in liver function tests
- Bradycardia
- Bronchospasm
- Nasal congestion
- Liver damage
- Depression
- Dyspnea
- Cardiac conduction disturbances
- Micturition disorders
- Poor eyesight
- Epigastric pain
- Ankle edema
- Hepatitis
- Rashes
- Lichenoid eruptions
- Temperature
- Tingling of the scalp
- Postural hypotension
- Jaundice
- Lethargy
- Systemic lupus erythematosus
- Headache
- Ejaculation failure
- Toxic myopathy
- Nausea
- Hepatic necrosis
- Positive antinuclear antibodies
- Itching
- Acute urinary retention
- Dryness of the nasal mucosa
- Dryness and eye irritation
- Vivid dreams
- Sweating
- Tremors
- Dizziness
- Vomiting
Contraindications and warnings associated with the use of Labetalol
Labetalol should not be taken in case of:
- Diabetic acidosis
- Nursing (breast-feeding)
- Atrioventricular block of second or third degree
- Grave marked bradycardia
- Heart failure resistant to treatment with digitalis
- Severe renal impairment
- Hypersensitivity to the active substance or to any of the drug ingredients (including lactose)
- Cardiogenic shock and other conditions associated with severe and prolonged hypotension
It is also important to pay attention or take special precautions in case of:
- Asthma and bronchospasm
- Liver damage
- Heart failure
Among the drugs with which it can interact are included:
- Calcium channel blockers of the verapamil type
- A Class I antiarrhythmic
- Amiodarone
- Anesthetics
- Tricyclic antidepressants
- Cimetidine
Finally, since it may cause dizziness and lethargy, labetalol should be taken with caution when you have to drive or operate hazardous machinery.
