Medicines & Supplements A to Z > Labetalol


Last updated on 12/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  




DRUG CLASS: Antihypertensives

SUB CLASS: Beta-blockers

USED FOR: High blood pressure, hypertension in pregnancy

– 100 mg, 200 mg (tablets)
– 5 mg/ml (injections)

What is Labetalol for?

Labetalol belongs to a class of medications called beta-blockers. It slows down the activity of your heart by stopping the transmission of messages from the nerves to your heart. It acts on the heart and blood vessels and therefore reduces blood pressure. Labetalol is used in emergency and regular treatment of hypertension, hypertension after myocardial infarction, and hypertension in pregnancy.

How to use it?

Labetalol can be taken by mouth for the treatment of regular hypertension and hypertension in pregnancy. Oral Labetalol should be taken with food immediately after meals.
Labetalol may also be injected through a needle into a vein as directed by your doctor for the treatment of hypertensive emergencies and hypertension after myocardial infarction.

High blood pressure
Oral: Initially 100 mg twice daily. May increase gradually at intervals of 14 days according to response to 200-400 mg twice daily. Maximum dosage is 2-4 g per day in 2-4 divided doses.
Oral: Initially 50-100 mg twice daily. Maintenance dose is 100-200 mg twice daily.

Hypertension in pregnancy
Oral: Initially 100 mg twice daily. May increase gradually at intervals of 14 days according to response to 200-400 mg twice daily. Maximum dosage is 2-4 g per day in 2-4 divided doses.
Intravenous infusion: Initially 20 mg/hour, which may be doubled every 30 minutes until satisfactory response. Usual maximum dosage is 160 mg/hour.

What are the side effects of Labetalol?

Common side effects of Labetalol include slow heartbeat, oedema, depression, dizziness, shortness of breath, erectile dysfunction, fatigue, headache, and heart failure.

Who should not take Labetalol?

– People allergic to Labetalol, other beta-blockers or any component of the formulation
– Patients with asthma, cardiogenic shock, low blood pressure, heart rate slower than normal, metabolic acidosis, second- or third-degree heart block

Pharmacist Tips:

– This medication can make you dizzy. Avoid driving or operating machinery until you know how you respond to Labetalol.
– Continue taking Labetalol even when you feel well.
– If you have diabetes, carefully monitor your blood sugar level as Labetalol may mask the symptoms of hypoglycaemia.

Common dosing schedule:
Labetalol should be taken immediately after meals.

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications Labetalol may interact with:
– Sympathomimetics, e.g. Epinephrine, Norepinephrine, Pseudoephedrine
– Insulin
– Tricyclic antidepressants, e.g. Amitriptyline, Doxepin
– Other medicines for treating hypertension, such as nitrates and calcium channel blockers
– Selective serotonin reuptake inhibitors, e.g. Fluoxetine, Sertraline

Labetalol can interact with a number of drugs. Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Labetalol in Hong Kong?

In Hong Kong, Labetalol is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Labetalol in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.