Methyldopa

Pronunciation: meth-ill-DOE-pa.

Generic name
methyldopa
Brand names
Aldomet (historical/current in several markets), Methyldopa Viatris/Mylan (New Zealand)
Drug class
Centrally-acting antihypertensive (aromatic-amino-acid decarboxylase inhibitor)
Form
Tablet, 250 mg and 500 mg
Route
Oral
Legal status
Prescription-only

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Aldomet (5) · Full directory

What methyldopa is and how it works

Methyldopa is an oral prescription medicine used to treat high blood pressure (hypertension). It works within the central nervous system to reduce signals that raise blood pressure. (1)

Methyldopa has a long, well-established track record specifically for treating high blood pressure during pregnancy, though it can be used for hypertension generally. Because it can rarely affect the liver or red blood cells, your prescriber will check blood tests before you start and periodically afterward, and your dose is individually adjusted based on your blood pressure response.

Mechanism of action: how methyldopa works

Methyldopa is converted centrally to alpha-methylnorepinephrine, which stimulates central inhibitory alpha-2 adrenergic receptors, reducing sympathetic outflow and lowering arterial blood pressure. (1)

What methyldopa is used for

Hypertension (high blood pressure)

Used to treat mild, moderate, or severe high blood pressure, often combined with other blood pressure medicines. (1)

Hypertension in pregnancy

Methyldopa has a long, well-established history of use for treating high blood pressure specifically during pregnancy, reflecting a favourable track record for the fetus reported over decades of clinical experience, and it remains a recognised option for this specific use even though it is prescribed less often now for general hypertension outside pregnancy. (1)

Before taking methyldopa

Do not take / not appropriate for

  • Do not take methyldopa if you have active liver disease (such as acute hepatitis or active cirrhosis), or if you have previously had a liver problem linked to methyldopa treatment. (all countries) (1)
  • Do not take methyldopa together with an MAO inhibitor medicine. (all countries) (1)
  • Do not take methyldopa if you have had an allergic reaction to it or any of its ingredients. (all countries) (1)

Tell your clinician about

  • Any personal history of liver problems.
  • Any history of anaemia or a positive Coombs test.
  • All other blood pressure medicines and other medications you take, including lithium and iron supplements.
  • Whether you are pregnant, planning pregnancy, or breastfeeding.
  • Any planned surgery or anaesthesia, since your anaesthetist may need to adjust dosing.
(1)

How to take methyldopa

  • Take methyldopa exactly as your prescriber directs; your starting dose, increases, and maintenance dose are individually determined based on your blood pressure response.
  • A typical starting approach described in labels is 250 mg two or three times a day for the first 48 hours, with adjustments made no more often than every 2 days -- but always follow your own prescriber's specific instructions rather than this general pattern.
  • Take methyldopa at the same times each day to help maintain steady blood pressure control.
  • If you also take an iron supplement, ask your pharmacist about timing, since iron can reduce methyldopa's effect.
(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

If you miss a dose, take it as soon as you remember unless it is nearly time for your next dose, in which case skip the missed dose and continue your regular schedule -- do not double up. Ask your pharmacist or prescriber if you are unsure.

Overdose

Seek urgent medical attention or contact a poison control service if an overdose is suspected. Overdose can cause very low blood pressure, marked drowsiness, or a slowed heart rate, and needs prompt medical assessment. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Sedation or drowsiness, usually transient and most noticeable when starting treatment or increasing the dose.

What to notice: Sedation or drowsiness, usually transient and most noticeable when starting treatment or increasing the dose.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Headache and weakness, often early symptoms.

What to notice: Headache and weakness, often early symptoms.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Lightheadedness on standing (orthostatic hypotension), fluid retention/swelling, diarrhea, and nausea.

What to notice: Lightheadedness on standing (orthostatic hypotension), fluid retention/swelling, diarrhea, and nausea.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Signs of liver problems — high caution

Symptoms: Fever appearing within the first 3 weeks of treatment, or yellowing of the skin or eyes (jaundice) appearing usually within the first 2 to 3 months, with or without fever.

Action: Contact your prescriber promptly for evaluation, including liver function testing. This is a rare but recognised risk, and in a small number of cases fatal liver injury has been reported, so prompt clinician assessment is important rather than waiting to see if it improves. Whether methyldopa is continued or restarted after such an episode is a decision for your prescriber based on the test results. (1)

Signs of hemolytic anemia — high caution

Symptoms: Unusual tiredness, pale skin, yellowing of the skin or eyes, or dark urine, typically after 6 to 12 months of treatment.

Action: Contact your prescriber promptly for blood testing, including a Coombs test -- a positive Coombs test occurs in some patients on long-term methyldopa and can occasionally be associated with hemolytic anemia, which needs recognition and management to avoid serious complications. (1)

Signs of very low blood pressure — emergency

Symptoms: Severe dizziness, fainting, or confusion, especially when standing up.

Action: Seek prompt medical attention, particularly if this is new, severe, or associated with falls. (1)

Interactions

  • Other blood pressure medicines can add to methyldopa's blood-pressure-lowering effect, which may need dose adjustment. (1)
  • Anaesthetic medicines may need dose reduction in patients taking methyldopa -- tell your anaesthetist you take it before any surgery. (1)
  • Lithium levels should be monitored carefully, as methyldopa can increase the risk of lithium toxicity. (1)
  • Iron supplements (ferrous sulfate or ferrous gluconate) taken with methyldopa are not recommended, since iron can reduce methyldopa's antihypertensive effect. (1)
  • MAO inhibitor medicines must not be combined with methyldopa. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Methyldopa is used during pregnancy only when clearly needed, and specifically for hypertension in pregnancy it has a long, well-established track record with generally favourable reported fetal outcomes. Discuss your individual situation with your prescriber. (1) (2) (3) (4) (5) (6)

Breastfeeding

Methyldopa passes into breast milk; use caution and discuss breastfeeding with your prescriber. (1) (2) (3) (4) (5) (6)

Children

Pediatric dosing is weight-based (around 10 mg/kg/day in 2-4 divided doses, up to a maximum of 65 mg/kg or 3 g daily, whichever is less) and individually determined by a pediatric prescriber. (1) (2) (3) (4) (5) (6)

Elderly

No specific age-based dose adjustment beyond usual individualised titration is described in the source reviewed; older adults may be more sensitive to blood-pressure-lowering and sedative effects. (1) (2) (3) (4) (5) (6)

Hepatic_impairment

Contraindicated in active liver disease; liver function is monitored during treatment given the rare hepatotoxicity risk. (1) (2) (3) (4) (5) (6)

Renal_impairment

Tell your prescriber about any kidney problems, since dosing may need adjustment. (1) (2) (3) (4) (5) (6)

Monitoring

Before starting

  • Baseline blood count
  • Baseline direct Coombs test
  • Baseline liver function tests
  • Baseline blood pressure

During treatment

  • Liver function monitoring, particularly during the first weeks to months of treatment.
  • Periodic blood counts and Coombs testing, particularly around 6 and 12 months of treatment.
  • Regular blood pressure checks to guide dose adjustment.
(1)

Storage

Store at 20-25°C (68-77°F) in a well-closed, child-resistant container, away from moisture.

Study the drug class: Centrally acting antihypertensives

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information; verify against the current full label before prescribing.

United States

Indication: Hypertension (adults)

Dose summary: Initial 250 mg two to three times daily for the first 48 hours; adjust at intervals of at least 2 days; usual maintenance 500 mg to 2 g daily in divided doses; maximum 3 g daily.

Renal context: Not specifically established as a major dose-adjustment factor in the source reviewed; individualised regardless. (1)

United States

Indication: Hypertension (pediatric)

Dose summary: Initial dosage based on 10 mg/kg/day in 2-4 divided doses; maximum 65 mg/kg or 3 g daily, whichever is less.

Renal context: Not established in the source reviewed. (1)

Mechanism of action

Hepatic guidance

Contraindicated in active hepatic disease; rare hepatotoxicity, including fatal hepatic necrosis, has been reported -- monitor liver function especially in the first weeks to months of treatment, and clinicians should not reinstitute methyldopa in a patient with a confirmed prior drug-related liver reaction.

Overdose note

Overdose can cause hypotension, sedation, and bradycardia; manage supportively with monitoring; contact a poison control service for guidance. (1)

Frequently asked questions

Is methyldopa available in the US, UK, Europe, Canada, Australia, and New Zealand?

Yes, generic methyldopa is available in all of these regions, though it is authorised through national procedures (not a single EU-wide EMA authorisation) within the European Union, which is typical for a medicine this long-established. (1) (2) (3) (4) (5) (6)

Why is methyldopa still used for high blood pressure in pregnancy?

Methyldopa has decades of real-world use specifically in pregnancy hypertension, with a reported track record of favourable fetal outcomes, which is why it remains a recognised option for this specific situation even though newer medicines are often preferred for general (non-pregnancy) high blood pressure. (1)

Why does methyldopa need regular blood tests?

With longer-term use, methyldopa can rarely cause a positive Coombs test and, occasionally, a type of anaemia caused by the immune system attacking red blood cells (haemolytic anaemia); it can also, rarely, cause liver problems. Your prescriber will typically arrange baseline and periodic blood counts, Coombs testing, and liver function tests, especially in the first year, to catch these early. (1)

What is the mechanism of action of methyldopa?

Methyldopa is converted centrally to alpha-methylnorepinephrine, which stimulates central inhibitory alpha-2 adrenergic receptors, reducing sympathetic outflow and lowering arterial blood pressure. (1)

What is the generic name of Methyldopa?

The generic name is methyldopa. It is sold under brand names including Aldomet (historical/current in several markets), Methyldopa Viatris/Mylan (New Zealand). (1)

What class of drug is methyldopa?

Methyldopa is classed as: Centrally-acting antihypertensive (aromatic-amino-acid decarboxylase inhibitor). (1)

References

  1. METHYLDOPA tablets -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information · United States · accessed 2026-07-29 · source 1
  2. Methyldopa Tablets 250 mg -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom · United Kingdom · accessed 2026-07-29 · source 2
  3. Methyldopa -- nationally authorised medicinal product across EU member statesNational medicines regulators of EU member states (methyldopa is nationally authorised, not centrally authorised by EMA) · European Union · accessed 2026-07-29 · source 3
  4. METHYLDOPA Tablets -- Product Monograph (multiple manufacturers)Health Canada product monograph · Canada · accessed 2026-07-29 · source 4
  5. ALDOMET methyldopa (as sesquihydrate) 250 mg tablet -- ARTG registrationTherapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-29 · source 5
  6. Methyldopa Viatris / Methyldopa Mylan 250 mg film-coated tablet -- New Zealand Data SheetMedsafe (New Zealand regulator) · New Zealand · accessed 2026-07-29 · source 6

Brand names by country

Single-ingredient methyldopa names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Methyldopa (generic tablets) (1)FDA approved currently labeled · 250 mg, 500 mg · multiple generic manufacturers

United Kingdom

  • Methyldopa (generic tablets, historically Aldomet) (2)MHRA licensed emc smpc confirmed · 250 mg · multiple UK generic manufacturers

Canada

  • Methyldopa (generic, historically Aldomet/Novo-Medopa/Apo-Methyldopa) (4)Health Canada approved confirmed · 250 mg, 500 mg · multiple Canadian generic manufacturers

Australia

  • Aldomet (5)TGA ARTG registered confirmed · 250 mg · Mylan Health Pty Ltd (current sponsor per ARTG)

New Zealand

  • Methyldopa Viatris / Methyldopa Mylan (6)Medsafe approved confirmed · 250 mg · Viatris/Mylan New Zealand
View brands in additional countries.

European Union

Methyldopa (nationally authorised generics) (3)

This page provides general reference information about methyldopa and is not a substitute for advice from the prescriber managing your treatment. All dosing and treatment decisions should be made with your prescriber.

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