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Combined α/β-blocker Pregnancy: §4.6: 'Although no teratogenic effects have been demonstrated in animals, Trandate should only be used during the first trimester of pregnancy if the potential benefit outweighs the potential risk. Trandate crosses the placental barrier and the possible consequences of alpha- and beta-adrenoceptor blockade in the foetus and neonate should be borne in mind. Perinatal and neonatal distress (bradycardia, hypotension, respiratory depression, hypoglycaemia, hypothermia) has been rarely reported. Sometimes these symptoms have developed a day or two after birth. Response to supportive measures (e.g. intravenous fluids and glucose) is usually prompt but with severe pre-eclampsia, particularly after prolonged intravenous labetalol, recovery may be slower. This may be related to diminished liver metabolism in premature babies. Beta-blockers reduce placental perfusion, which may result in intrauterine foetal death, immature and premature deliveries. There is an increased risk of cardiac and pulmonary complications in the neonate in the post-natal period. Intra-uterine and neonatal deaths have been reported with Trandate but other drugs (e.g. vasodilators, respiratory depressants) and the effects of pre-eclampsia, intra-uterine growth retardation and prematurity were implicated. Such clinical experience warns against unduly prolonging high dose labetalol and delaying delivery and against co-administration of hydralazine.' Breast-feeding: 'Trandate is excreted in breast milk. Breast-feeding is therefore not recommended. Nipple pain and Raynaud's phenomenon of the nipple have been reported.'

Labetalol hydrochloride

Brand names: Trandate

Used in: Pre-eclampsia & Obstetric Emergencies

Labetalol hydrochloride is a combined alpha- and beta-adrenoceptor blocker used to treat hypertension, including hypertension in pregnancy and hypertensive emergencies, and is available in oral and intravenous forms.

Adult dose

Dose: ORAL HYPERTENSION ONLY (the IV regimen is not in this bundle - see notes). 'Treatment should start with 100mg twice daily. In patients already being treated with antihypertensives and in those of low body weight this may be sufficient to control blood pressure. In others, increases in dose of 100mg twice daily should be made at fortnightly intervals. Many patients' blood pressure is controlled by 200mg twice daily and up to 800mg daily may be given as a twice daily regimen. In severe, refractory hypertension, daily doses up to 2400mg have been given. Such doses should be divided into a three or four times a day regimen.' Elderly: 'an initial dose of 50mg twice daily is recommended.'
Route: Oral - 'Trandate tablets should be taken orally with food.'
Frequency: Twice daily; three or four times daily for the higher total daily doses.
Max: Maximum total daily dose 2400 mg, in three or four divided doses - 'A total daily dose of 2400mg should not be exceeded' (stated in the hypertension-of-pregnancy paragraph of §4.2; the general severe/refractory hypertension paragraph independently tops out at the same figure, 'daily doses up to 2400mg have been given').
SCOPE - ORAL ONLY. This bundle contains only tablet labelling. §4.2 says only 'If rapid reduction of blood pressure is necessary, see the SPC for Trandate Injection'. HYPERTENSION OF PREGNANCY (§4.2, same tablets): 'The initial dose of 100mg twice daily may be increased, if necessary, at weekly intervals by 100mg twice daily. During the second and third trimester, the severity of the hypertension may require further dose titration to a three times daily regimen, ranging from 100mg tds to 400mg tds... Hospital in-patients with severe hypertension, particularly of pregnancy, may have daily increases in dosage' - note the WEEKLY, not fortnightly, titration interval in pregnancy. SWITCHING FROM IV: 'If long-term control of hypertension following the use of Trandate Injection is required, oral therapy with Trandate tablets should start with 100mg twice daily.' TRANSFERRING FROM OTHER ANTIHYPERTENSIVES: introduce at 100mg twice daily and decrease the previous therapy gradually; 'Additive hypotensive effects may be expected'; 'Abrupt withdrawal of clonidine or beta-blocking agents is undesirable.' ANGINA WITH HYPERTENSION: 'the dose of Trandate will be that required to control the hypertension.' STOPPING: reduce gradually over 1-2 weeks (§4.4); if beta-blockade is interrupted before surgery, discontinue for at least 24 hours. CHILDREN: 'Safety and efficacy in children have not been established' - hence paedDose null. US CROSS-CHECK (figures differ, do not merge with the UK regimen): initial 100 mg twice daily, titrated 'in increments of 100 mg b.i.d. every 2 or 3 days' rather than fortnightly, usual maintenance 200-400 mg twice daily, severe hypertension 1200-2400 mg per day, and 'Titration increments should not exceed 200 mg b.i.d.'; elderly majority need 100-200 mg twice daily.

Dose adjustments

Renal

No renal dose adjustment is given in either label. §4.8 records hyperkalaemia 'particularly in patients who may have impaired renal excretion of potassium', and acute retention of urine and difficulty in micturition are listed as renal/urinary adverse effects.

Hepatic

No dose adjustment is given, but §4.4 carries a stopping rule: 'There have been rare reports of severe hepatocellular injury with Labetalol therapy. The hepatic injury is usually reversible and has occurred after both short and long term treatment. Appropriate laboratory testing should be done at the first sign or symptom of liver dysfunction. If there is laboratory evidence of liver injury or the patient is jaundiced, labetalol therapy should be stopped and not re-started.'

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Cardiogenic shock
  • Uncontrolled, incipient or digitalis-refractory heart failure
  • Sick sinus syndrome (including sino-atrial block)
  • Second or third degree heart block
  • Prinzmetal's angina
  • History of wheezing or asthma
  • Untreated phaeochromocytoma
  • Metabolic acidosis
  • Bradycardia (<45-50 bpm)
  • Hypotension
  • Hypersensitivity to labetalol
  • Severe peripheral circulatory disturbances
  • US label cross-check (same list in substance, different wording): 'contraindicated in bronchial asthma, overt cardiac failure, greater-than-first-degree heart block, cardiogenic shock, severe bradycardia, other conditions associated with severe and prolonged hypotension, and in patients with a history of hypersensitivity to any component of the product... Beta-blockers, even those with apparent cardioselectivity, should not be used in patients with a history of obstructive airway disease, including asthma.'

Side effects

  • Cardiac: bradycardia, heart block, heart failure, hypotension
  • Vascular: postural hypotension, ankle oedema, increase of an existing intermittent claudication, cold or cyanotic extremities, Raynaud's phenomenon, paraesthesia of the extremities
  • Nervous system: headache, tiredness, dizziness; 'tremor has been reported in the treatment of hypertension of pregnancy'
  • Respiratory: bronchospasm (in patients with asthma or a history of asthma), nasal congestion, interstitial lung disease
  • Hepato-biliary: raised liver function tests, jaundice (both hepatocellular and cholestatic), hepatitis and hepatic necrosis - §4.4 adds 'There have been rare reports of severe hepatocellular injury with Labetalol therapy'
  • Gastrointestinal: epigastric pain, nausea, vomiting, diarrhoea
  • Psychiatric: depressed mood and lethargy, hallucinations, psychoses, confusion, sleep disturbances, nightmares
  • Skin: sweating, tingling sensation in the scalp (usually transient, early in treatment), reversible lichenoid rash, systemic lupus erythematosus, exacerbation of psoriasis, reversible alopecia
  • Eye: impaired vision, dry eyes
  • Blood: rare positive antinuclear antibodies unassociated with disease, hyperkalaemia (particularly where renal excretion of potassium may be impaired), thrombocytopenia
  • Renal/genitourinary: acute retention of urine, difficulty in micturition; ejaculatory failure
  • Musculoskeletal: cramps, toxic myopathy
  • General: hypersensitivity (rash, pruritus, angioedema and dyspnoea), drug fever, masking of the symptoms of thyrotoxicosis or hypoglycaemia; nipple pain and Raynaud's phenomenon of the nipple (frequency not known)
  • 'Most side-effects are transient and occur during the first few weeks of treatment.' US trial rates (probably drug-related, n=227 vs 98 placebo): nausea 6% vs 1%, fatigue 5% vs 0%, dyspepsia 3% vs 1%, headache 2% vs 1%; counting all reports, dizziness 20%, nausea 14%, fatigue 11%.

Monitoring

  • Blood pressure - titrate against standing blood pressure; the full antihypertensive effect of a dose or dose increment 'is usually seen within the first 1 to 3 hours', and continued-dosing effect is measured 'approximately 12 hours after a dose' at subsequent visits (US label)
  • Pulse rate - 'Beta-blockers may induce bradycardia. If the pulse rate decreases to less than 50-55 beats per minute at rest and the patient experiences symptoms related to the bradycardia, the dosage should be...' (§4.4, truncated at the source-fetch limit; bradycardia <45-50 bpm is a §4.3 contraindication)
  • Liver function - 'Appropriate laboratory testing should be done at the first sign or symptom of liver dysfunction. If there is laboratory evidence of liver injury or the patient is jaundiced, labetalol therapy should be stopped and not re-started.'
  • Cardiac reserve and heart failure - 'Due to negative inotropic effects, special care should be taken with patients whose cardiac reserve is poor and heart failure should be controlled before starting Trandate therapy'; do not interrupt or discontinue abruptly, particularly in ischaemic heart disease
  • Peri-operative - inform the anaesthetist, give intravenous atropine before induction, and watch blood loss and blood volume closely because labetalol 'may mask the compensatory physiological responses to sudden haemorrhage (tachycardia and vasoconstriction)'
  • Watch for masked signs of thyrotoxicosis or hypoglycaemia (§4.8), and for skin rashes or dry eyes, which usually clear on withdrawal (§4.4)

Clinical monograph

How it works

It blocks beta-1, beta-2 and peripheral alpha-1 adrenoceptors, reducing heart rate and cardiac output while lowering peripheral vascular resistance, producing a fall in blood pressure without marked reflex tachycardia.

Prescribing in practice

  • As a non-selective beta-blocker it is contraindicated in asthma and should be used with great caution in any reversible airways disease because of the risk of bronchospasm.
  • Intravenous use requires close haemodynamic monitoring, and patients should remain supine during and shortly after intravenous administration because of the risk of postural hypotension.
  • It is a recognised first-line option for hypertension in pregnancy but can rarely cause severe hepatocellular injury.

Monitoring

Monitor blood pressure and heart rate closely (continuously during intravenous use), and review liver function if hepatic dysfunction is suspected.

Counselling the patient

  • Do not stop this medicine suddenly, as abrupt withdrawal can worsen angina or raise blood pressure.
  • After an intravenous dose, stay lying down for a while to avoid fainting when you stand.
  • Report yellowing of the skin or eyes, dark urine or persistent nausea, which may signal a liver problem.

Evidence & guidelines

Labetalol is recommended by NICE as a first-line treatment for hypertension in pregnancy and is a long-established agent for hypertensive emergencies.

Reference: NICE NG133; ESC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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