Labetalol

What is labetalol?

Labetalol is a prescription-only beta-blocker used to treat high blood pressure (hypertension). It works by slowing the heart rate and relaxing blood vessels, which helps reduce blood pressure. It is available as tablets for regular use and as an injection in hospital settings[1]. 

What is labetalol used to treat?

Labetalol is prescribed to treat[1]: 

• High blood pressure in general 

• High blood pressure during pregnancy 

• Angina (chest pain caused by reduced blood flow to the heart) 

Reducing high blood pressure, helps to prevent future heart disease, heart attacks, and strokes. 

How does labetalol work?

Labetalol blocks beta-adrenergic receptors and alpha-1-adrenergic receptors in the heart and blood vessels[1]. This: 

• Slows the heart rate 

• Reduces the force of heart contractions 

• Relaxes blood vessels 

Together, these actions lower blood pressure and reduce the workload on the heart[1]. 

Who can take labetalol?

Labetalol is suitable for most adults and is not licensed for use in children. However, you should speak to your doctor first if you[1]: 

• Have asthma, lung disease or serious breathing problems 

• Have very low blood pressure or a slow heart rate 

• Have heart rhythm disorders, heart failure, or recently had a heart attack 

• Have sick sinus syndrome and do not have a pacemaker 

• Have Prinzmetal’s angina (chest pain while resting) 

• Have liver or kidney problems 

• Have severe circulation problems (such as Raynaud’s) 

• Have untreated pheochromocytoma (a rare adrenal tumour) 

• Are allergic to labetalol or any other beta-blockers, or any of the ingredients listed as part of your medicine 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2].

What is the typical dosage of labetalol?

Labetalol comes as 100mg, 200mg, and 400mg strength tablets. Dosage depends on the condition and individual response[1]: 

• Adults – usually start at 100mg twice a day, potentially increasing gradually up to a maximum of 2,400mg per day if your blood pressure remains high, but the standard dose is between 400mg and 800mg a day, split into two divided doses 

• Once you find a dose that works for you, you’ll usually stay on that for the depending on your blood pressure readings. 

How do you take labetalol?

You should take labetalol with food or just after a meal to reduce the chance of stomach upset. Try and space your doses out evenly through the day[1]. 

What do you do if you take too much labetalol?

Too much labetalol can cause[1]: 

• Drop in blood pressure 

• Very slow heart rate 

• Breathing problems 

• Drowsiness or confusion 

Call NHS 111 or go to A&E immediately. Take the medicine packaging with you. 

What do you do if you forget to take labetalol?

Take it as soon as you remember. If it’s nearly time for the next dose, skip the missed dose. Do not take two doses at once to make up for a missed one[1]. 

How do you store labetalol?

Store at room temperature in a dry place out of the reach of children. Keep it in the original container[1]. 

How do I store sotrovimab?

Sotrovimab is stored by healthcare professionals. It requires controlled conditions and is not meant for home storage[1]. 

What medicines can’t you take with labetalol?

Labetalol may interact with[1]: 

• Other blood pressure medicines (may lower blood pressure too much) 

• Heart medications like digoxin, amiodarone, flecainide, verapamil, or diltiazem 

• Clonidine 

• Other beta-blockers 

• Antidepressants such as tricyclics or MAOIs 

• Adrenaline injections 

• Antimalarial medicines e.g. mefloquine or quinine 

• Aminophylline or theophylline 

• NSAIDs like ibuprofen 

• Some Parkinson’s disease medications 

• Baclofen 

• Tamsulosin 

• Cough medications 

• Diabetes medications – may hide signs of low blood sugar 

• Asthma medicines – may reduce their effectiveness 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of labetalol?

Common side effects include[1]: 

• Dizziness or light-headedness 

• Tiredness or weakness 

• Nausea or vomiting 

• Diarrhoea  

• Stomach pain 

• Cold hands and feet 

Serious side effects include[1]: 

• Breathing difficulties or wheezing 

• Slow or irregular heartbeat 

• Chest pain 

• Unexplained bruising as a sign of low platelets in your blood, or thrombocytopenia 

• Yellowing of the skin or eyes (possible liver problems) 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include[1]:  

• Difficulty breathing  

• Tightness in throat and chest  

• Swelling of the tongue or throat  

• Feeling faint or dizzy  

• Blue/grey skin or lips  

• Loss of consciousness 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about labetalol

How quickly does labetalol work? 
It starts working within a few hours, but the full effect may take a few days[1]. 

Can I drink alcohol with labetalol? 
Yes, but alcohol may increase dizziness or drowsiness[1]. 

Is labetalol safe in pregnancy? 
Yes, it’s commonly used for managing high blood pressure in pregnancy[1]. 

Can I drive while taking labetalol? 
Yes, unless you feel dizzy or light-headed[1]. 

Can I take labetalol long-term? 
Yes. It’s often prescribed for long-term use under medical supervision[1]. 

Can labetalol affect my mood? 
Rarely, some people may experience mood changes or depression[1]. 

For the official NHS guide to labetalol, visit their website.