Labetalol

Managing high blood pressure is a long-term commitment that often involves finding the right medicine for your individual circumstances. Labetalol tablets are a prescription-only antihypertensive medication that works through a dual mechanism, blocking both alpha and beta adrenoceptors to lower blood pressure. This combination of actions gives labetalol a distinct profile within cardiovascular therapy. A prescription can only be issued following a clinical consultation.

Labetalol tablets are an oral prescription medicine containing labetalol hydrochloride as the active ingredient. Labetalol is a combined alpha and beta adrenoceptor blocker. It blocks both alpha-1 adrenoceptors (found in blood vessel walls) and beta adrenoceptors (found in the heart and blood vessels), giving it a dual mechanism of action that distinguishes it from standard beta blockers.

Labetalol is licensed in the UK for the treatment of hypertension (high blood pressure) in adults. It is available in three strengths: 100 mg, 200 mg, and 400 mg. Labetalol is available as a generic medicine from multiple manufacturers.

Labetalol is sometimes used in clinical settings where other antihypertensive medicines have been insufficient or are not appropriate, and it may be used alongside other medicines as part of a broader blood pressure control plan. Your prescriber will assess your full medical history before recommending labetalol as part of your cardiovascular therapy.

Labetalol lowers blood pressure through two complementary mechanisms acting on different types of adrenoceptors in the body.

Beta Adrenoceptor Blockade

Beta adrenoceptors are found in the heart and blood vessels. When stimulated by adrenaline and noradrenaline, beta receptors increase the heart rate and force of contraction. Labetalol blocks beta-1 receptors in the heart, reducing the heart rate and the force with which the heart pumps. This reduces the amount of blood the heart pushes out with each beat, lowering cardiac output and contributing to a fall in blood pressure. Labetalol also blocks beta-2 receptors, though its overall effect on heart rate tends to be more moderate than that of standard selective beta blockers.

Alpha Adrenoceptor Blockade

Alpha-1 adrenoceptors are found in the smooth muscle of blood vessel walls. When stimulated, they cause the vessels to narrow (constrict), raising blood pressure. Labetalol blocks these alpha-1 receptors, preventing this constriction and allowing blood vessels to remain relaxed and widened. This peripheral vasodilation reduces the resistance against which the heart must pump, lowering blood pressure independently of the beta-blocking effect.

The combination of reduced cardiac output from beta blockade and reduced vascular resistance from alpha blockade produces a balanced and effective blood pressure lowering effect. This dual action is reflected in labetalol's profile as an antihypertensive that lowers blood pressure without causing the reflex increase in heart rate sometimes seen with medicines that act only on blood vessels.

Always take labetalol exactly as your prescriber instructs. The information below summarises key points from the current UK SmPC. Read the Patient Information Leaflet supplied with your medicine before starting treatment.

• Labetalol tablets are taken twice daily, in the morning and in the evening. Some patients may be instructed to take doses three times daily. Follow your prescriber's specific instructions.
• Take labetalol with or just after food. Food increases the absorption of labetalol and helps to achieve more consistent blood levels.
• Swallow the tablet whole with a glass of water.
• If you miss a dose, take it as soon as you remember on the same day. If it is close to the time of your next scheduled dose, skip the missed dose and continue as normal. Do not take two doses at once.
• Do not stop taking labetalol suddenly without speaking to your prescriber first. Stopping a beta blocker abruptly can cause a rebound increase in blood pressure and, in patients with coronary artery disease, may trigger chest pain or other serious cardiac events. Your prescriber will guide you on how to reduce the dose gradually if stopping is necessary.
• Labetalol can cause dizziness, particularly when standing up from a seated or lying position. This is more likely when first starting treatment or after a dose increase. Stand up slowly and pause briefly before walking to reduce this risk.

Labetalol tablets are available in three strengths. Dosing is typically titrated upward based on blood pressure response, with the prescriber selecting the appropriate dose and frequency for each patient.

Labetalol 100 mg Tablets

The 100 mg tablet is the starting dose for most adults beginning labetalol treatment. The usual starting dose is 100 mg twice daily. The 100 mg strength allows dose titration to begin at a level that can be assessed for tolerability and blood pressure response before any increase is considered.

Labetalol 200 mg Tablets

The 200 mg tablet is used as the dose is increased to achieve adequate blood pressure control. Doses of 200 mg twice or three times daily are within the usual therapeutic range. The 200 mg strength allows flexible dosing without requiring patients to take multiple lower strength tablets.

Labetalol 400 mg Tablets

The 400 mg tablet supports higher daily doses where required. The maximum recommended oral dose is 2,400 mg per day in divided doses, though most patients will achieve adequate blood pressure control at lower doses. Doses above 800 mg per day are generally used under specialist supervision. All dose adjustments are clinical decisions to be made by your prescriber. Do not change your dose without medical advice.

Because labetalol requires dose titration and close monitoring of blood pressure and heart rate, it is particularly important to attend all follow up appointments your prescriber arranges.

Like all medicines, labetalol can cause side effects, although not everyone experiences them. The information below is based on the current UK SmPC. Refer to the Patient Information Leaflet for the full list of side effects.

Common Side Effects (may affect up to 1 in 10 people)

• Dizziness or lightheadedness, particularly on standing up quickly (postural hypotension). This is related to the alpha-blocking component of labetalol.
• Headache
• Fatigue or weakness
• Nausea
• Tingling of the scalp, particularly at the start of treatment. This is a recognised effect of labetalol and usually diminishes over time.

Uncommon Side Effects (may affect up to 1 in 100 people)

• Slow heart rate (bradycardia)
• Vomiting or stomach upset
• Skin rash or itching
• Difficulty passing urine (urinary retention)
• Nasal congestion

Rare but Important Side Effects

Liver damage: labetalol has been associated with hepatotoxicity in rare cases. If you develop jaundice (yellowing of the skin or whites of the eyes), dark urine, or persistent upper abdominal pain, contact your doctor promptly. Liver function tests may be performed periodically during treatment.

Worsening of heart failure or bronchospasm: labetalol is contraindicated in uncontrolled heart failure and asthma. If you develop breathlessness, wheeze, or ankle swelling, seek medical advice promptly.

Serious Side Effects: Seek Urgent Medical Attention

Go to your nearest accident and emergency department or call 999 immediately if you experience:

• Severe breathlessness or wheeze
• Signs of a severe allergic reaction such as sudden swelling of the face, lips, tongue, or throat
• Very slow heart rate, fainting, or collapse

Report any suspected side effect to your prescriber, pharmacist, or via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

Labetalol Tablets May Be Suitable If You:

• Are an adult aged 18 or over with a confirmed diagnosis of hypertension
• Have high blood pressure that has not been adequately controlled by other antihypertensive medication, or where a combined alpha and beta blocker is considered clinically appropriate
• Are already prescribed labetalol and require a repeat prescription through an online prescribing service

Labetalol Tablets Are Not Suitable If You:

• Have asthma or a history of obstructive airways disease. Labetalol is contraindicated in these patients due to the risk of bronchospasm from its beta-blocking action.
• Have uncontrolled heart failure
• Have a very slow resting heart rate (bradycardia) or certain heart rhythm problems, including second or third degree heart block
• Have cardiogenic shock
• Have severe peripheral artery disease or Raynaud's phenomenon
• Have a phaeochromocytoma that has not been adequately treated with an alpha blocker first. Starting a beta blocker before alpha blockade is in place in phaeochromocytoma can cause a dangerous rise in blood pressure.
• Are under 18 years of age
• Have a known allergy or hypersensitivity to labetalol or any excipient listed in the SmPC

Labetalol may be used during pregnancy under specialist supervision, as it is among the antihypertensive medicines used clinically in this setting in the UK. However, prescribing decisions for hypertension in pregnancy require specialist obstetric and clinical input. Online prescribing for hypertension in pregnancy is not appropriate through this service. If you are pregnant and require blood pressure treatment, please speak to your GP or maternity team.

Tell your prescriber about all medicines you take. The following interactions are of particular clinical importance:

• Other antihypertensive medicines: combining labetalol with other blood pressure lowering medicines can enhance the blood pressure lowering effect and increase the risk of low blood pressure.
• Calcium channel blockers of the verapamil or diltiazem type: combining these with labetalol can cause an excessive slowing of the heart rate and impaired heart function. This combination requires careful prescriber assessment.
• Cimetidine: may increase labetalol blood levels.
• Tricyclic antidepressants: may increase the risk of tremor and blood pressure lowering effects.
• Anaesthetic agents: labetalol may enhance the blood pressure lowering effects of general anaesthesia. Inform your anaesthetist before any surgical procedure that you are taking labetalol.
• Insulin and oral antidiabetic medicines: labetalol may mask some signs of low blood sugar (hypoglycaemia) such as fast heart rate. Patients with diabetes should be aware of this and monitor their blood glucose accordingly.

Your prescriber will review all of your current medicines during the clinical assessment before any prescription is considered.

Labetalol is a Prescription Only Medicine. The clinical consultation is the essential first step. A prescription will only be issued if a registered prescriber concludes, based on their individual assessment of your circumstances, that labetalol is clinically appropriate for you.

During your online consultation with Pharmacy Planet, a registered prescriber will review your clinical information. This includes your blood pressure history, heart rate, any cardiac or respiratory conditions, current medicines, and any other relevant medical history. Labetalol requires careful assessment in patients with conditions such as diabetes, asthma, heart disease, or peripheral vascular disease. The prescriber will use all available information to determine whether labetalol is appropriate, which dose is suitable, and whether any further assessment is needed before prescribing.

If you are under the care of a GP, cardiologist, or other specialist for hypertension or a related condition, please keep them informed of all medicines prescribed through online services. Coordinated care supports the safest approach to BP regulation and heart protection.

• Store below 25°C.
• Store in the original packaging to protect from light and moisture.
• Keep out of the sight and reach of children.
• Do not use after the expiry date printed on the packaging.
• Do not dispose of medicines via household waste or wastewater. Return unused or out of date tablets to your pharmacist for safe disposal.
• Full storage instructions are provided in the Patient Information Leaflet supplied with your medicine.

The table below compares beta blocker tablets available at Pharmacy Planet. Beta blockers reduce heart rate and cardiac output to lower blood pressure. They differ in cardioselectivity, additional properties, and licensed indications.

Important: This comparison is for general information only and does not replace medical advice. A prescriber will decide which treatment is suitable for you following an online consultation.

Pharmacy Planet is a GPhC-registered online pharmacy providing access to prescription medicines through a clinically led consultation process. Our registered prescribers and pharmacists are committed to patient safety, clinical accuracy, and responsible prescribing.

We follow GPhC standards, MHRA guidance, and ASA advertising regulations in all aspects of our service. Every prescription is reviewed and dispensed by qualified healthcare professionals. We aim to provide the clear, factual information you need to understand your antihypertensive medication and to support informed conversations with your healthcare team.

If you have questions about labetalol, blood pressure control, or cardiovascular therapy more broadly, our pharmacy team is available to help. We are committed to transparent, patient centred care.

References

1. Electronic Medicines Compendium (eMC). Labetalol 100 mg, 200 mg and 400 mg tablets — Summary of Product Characteristics. https://www.medicines.org.uk/emc. Accessed May 2026.
2. National Institute for Health and Care Excellence (NICE). Hypertension in adults: diagnosis and management. NICE guideline NG136. https://www.nice.org.uk/guidance/ng136. Accessed May 2026.
3. NHS. High blood pressure (hypertension). https://www.nhs.uk/conditions/high-blood-pressure-hypertension. Accessed May 2026.
4. Joint Formulary Committee. British National Formulary (BNF). Labetalol hydrochloride. BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk. Accessed May 2026.
5. Medicines and Healthcare products Regulatory Agency (MHRA). Yellow Card — report a side effect. https://yellowcard.mhra.gov.uk. Accessed May 2026.