Methyldopa
Methyldopa is an older oral blood pressure medicine used to treat high blood pressure (hypertension).
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 2 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Methyldopa (Aldomet) is an older standby for high blood pressure, on the market since about 1962 and available as a generic, that calms the brain signals tightening blood vessels; rarely a first choice now, it still has a place in pregnancy. Most people tolerate it well, though sleepiness is common early on, along with dry mouth and a stuffy nose. Watch for rare but serious liver injury and hemolytic anemia (red blood cells breaking down too fast), so keep up with blood tests and report fever, yellowing skin or eyes, or unusual tiredness promptly. Never stop it suddenly, because blood pressure usually rebounds within about 48 hours.
Clinical pearls
- Do not take iron supplements such as ferrous sulfate or ferrous gluconate with it, because they reduce methyldopa absorption.
- Mention methyldopa before surgery or a transfusion, since anesthetic doses may need lowering and its common positive Coombs test complicates blood matching.
- It must never be combined with an MAO inhibitor antidepressant, and anyone on lithium needs close watching for lithium toxicity.
- If your dose is raised, the increase is often taken in the evening so the extra sleepiness falls overnight.
Patient information guide A plain-language walkthrough of Methyldopa, written from its FDA label.
What Methyldopa is used for
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Methyldopa is used for one condition across its supported products.
- High blood pressure (hypertension): labeled for both Methyldopa oral tablets and Methyldopa oral film-coated tablets.
How Methyldopa works
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Methyldopa is changed in the body into alpha-methylnorepinephrine. This substance stimulates inhibitory receptors in the brain that reduce signals telling blood vessels to tighten. That lowers blood pressure.
It may also work through false neurotransmission and by lowering plasma renin activity. The exact mechanism has not been conclusively shown.
Methyldopa dosage
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Methyldopa is taken by mouth, usually in two to four doses a day. Your prescriber begins with a low dose and adjusts it gradually, often no faster than every couple of days.
- Increases are often started in the evening to limit sleepiness.
- Other blood pressure medicines may need to be adjusted when methyldopa is started.
- Kidney problems may mean you need smaller doses.
- Children’s doses are based on body weight.
Follow your prescriber and the pharmacy label. Blood pressure usually returns to its starting level within about 48 hours of stopping.
Dosing details from the FDA-approved label
From the Methyldopa prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Adults – Initiation of Therapy
- 250 mg two to three times a day in the first 48 hours
- The daily dosage then may be increased or decreased, preferably at intervals of not less than 2 days, until an adequate response is achieved
- To minimize sedation, start dosage increases in the evening
- Adults – Initiation of Therapy when given with antihypertensives other than thiazides
- Initial dosage limited to 500 mg daily in divided doses
- When added to a thiazide, the dosage of thiazide need not be changed; doses of other antihypertensives may need adjustment for a smooth transition
- Adults – Maintenance of Therapy
- 500 mg to 2 g daily in two to four doses
- Maximum: 3 g daily (maximum recommended daily dosage)
- Patients with impaired renal function may respond to smaller doses; syncope in older patients may be avoided by lower doses
- Pediatric Patients
- Initial dosage based on 10 mg/kg of body weight daily in two to four doses
- The daily dosage then is increased or decreased until an adequate response is achieved
- Maximum: 65 mg/kg or 3 g daily, whichever is less
- Based on body weight
Read the label’s full dosing text
DOSAGE & ADMINISTRATION Adults : Initiation of Therapy : The usual starting dosage of methyldopa tablets is 250 mg two to three times a day in the first 48 hours. The daily dosage then may be increased or decreased, preferably at intervals of not less than 2 days, until an adequate response is achieved. To minimize the sedation, start dosage increases in the evening. By adjustment of dosage, morning hypotension may be prevented without sacrificing control of afternoon blood pressure. When methyldopa tablets are given to patients on other antihypertensives, the dose of these agents may need to be adjusted to effect a smooth transition. When methyldopa tablets are given with anti-hypertensives other than thiazides, the initial dosage of methyldopa tablets should be limited to 500 mg daily in divided doses; when methyldopa tablets are added to a thiazide, the dosage of thiazide need not be changed. Maintenance of Therapy : The usual daily dosage of methyldopa tablets is 500 mg to 2 g in two to four doses. Although occasional patients have responded to higher doses, the maximum recommended daily dosage is 3 g. Once an effective dosage range is attained, a smooth blood pressure response occurs in most patients in 12 to 24 hours. Since methyldopa has a relatively short duration of action, withdrawal is followed by return of hypertension usually within 48 hours. This is not complicated by an overshoot of blood pressure. Occasionally tolerance may occur, usually between the second and third month of therapy. Adding a diuretic or increasing the dosage of methyldopa frequently will restore effective control of blood pressure. A thiazide may be added at any time during methyldopa therapy and is recommended if therapy has not been started with a thiazide or if effective control of blood pressure cannot be maintained on 2 g of methyldopa daily. Methyldopa is largely excreted by the kidney and patients with impaired renal function may respond to smaller doses. Syncope in older patients may be related to an increased sensitivity and advanced arteriosclerotic vascular disease. This may be avoided by lower doses. Pediatric Patients : Initial dosage is based on 10 mg/kg of body weight daily in two to four doses. The daily dosage then is increased or decreased until an adequate response is achieved. The maximum dosage is 65 mg/kg or 3 g daily, whichever is less.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Methyldopa side effects
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Most people tolerate methyldopa well, and early side effects often fade.
Common side effects
- Sleepiness or sedation, usually temporary
- Headache
- Weakness or tiredness
- Dizziness or light-headedness
- Dry mouth
- Nausea, vomiting, diarrhea or constipation
- Nasal stuffiness
- Swelling or weight gain
When to get medical help
- Yellowing of the skin or eyes (jaundice), or an unexplained fever, especially in the first weeks to months. These can signal liver problems, and the medicine should be stopped.
- Signs of anemia from red blood cell breakdown (hemolytic anemia), such as unusual tiredness or paleness. Call your doctor promptly.
- Fainting or marked dizziness when standing, especially if you are older.
- Worsening chest pain (angina), heart failure symptoms, or a very slow heartbeat.
- Severe skin reactions or rash.
- Mood changes, depression, nightmares or confusion.
- Unusual infections, bruising or bleeding, which can reflect low blood cell counts.
- Joint pain or swelling, or a lupus-like illness.
Methyldopa warnings and precautions
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- Liver problems: Rarely, methyldopa can cause hepatitis, jaundice or fatal liver damage, usually in the first 2 to 3 months. Liver tests are advised, especially in the first 6 to 12 weeks or with unexplained fever.
- Hemolytic anemia: Rarely, red blood cells break down. Blood counts are advised before and during treatment.
- Positive Coombs test: Seen in 10 to 20 percent of people on long-term use. It can complicate blood matching for transfusions.
- Low blood cell counts: Reversible drops in white cells and platelets have been reported rarely.
- If liver problems or hemolytic anemia are linked to methyldopa, it should not be restarted.
Methyldopa interactions
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Methyldopa can clash with several medicines and supplements.
- MAO inhibitors: contraindicated.
- Other blood pressure medicines: effects can add together.
- Lithium: risk of lithium toxicity, so close monitoring is needed.
- Iron (ferrous sulfate or gluconate): lowers methyldopa absorption and may weaken blood pressure control. Not recommended together.
- Anesthetics: lower doses may be needed.
Interactions listed in the FDA-approved label
From the Methyldopa prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Other antihypertensive drugs: Potentiation of antihypertensive effect may occur. Follow patients carefully to detect side reactions or unusual manifestations of drug idiosyncrasy.
- Anesthetics: Patients may require reduced doses of anesthetics when on methyldopa. If hypotension occurs during anesthesia, it usually can be controlled by vasopressors; adrenergic receptors remain sensitive during methyldopa treatment.
- Lithium: Concomitant use with methyldopa may cause symptoms of lithium toxicity. Monitor the patient carefully for symptoms of lithium toxicity; read the circular for lithium preparations.
- Ferrous sulfate or ferrous gluconate: Bioavailability of methyldopa is decreased when ingested with these, which may adversely affect blood pressure control. Coadministration is not recommended.
- Monoamine oxidase (MAO) inhibitors: Label refers to the Contraindications section. See CONTRAINDICATIONS.
Read the label’s full interactions text
Drug Interactions When methyldopa is used with other antihypertensive drugs, potentiation of antihypertensive effect may occur. Patients should be followed carefully to detect side reactions or unusual manifestations of drug idiosyncrasy. Patients may require reduced doses of anesthetics when on methyldopa. If hypotension does occur during anesthesia, it usually can be controlled by vasopressors. The adrenergic receptors remain sensitive during treatment with methyldopa. When methyldopa and lithium are given concomitantly, the patient should be carefully monitored for symptoms of lithium toxicity. Read the circular for lithium preparations. Several studies demonstrate a decrease in the bioavailability of methyldopa when it is ingested with ferrous sulfate or ferrous gluconate. This may adversely affect blood pressure control in patients treated with methyldopa. Coadministration of methyldopa with ferrous sulfate or ferrous gluconate is not recommended. Monoamine oxidase (MAO) inhibitors: See CONTRAINDICATIONS .
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Methyldopa
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- Do not use with active liver disease, such as acute hepatitis or active cirrhosis.
- Do not use if methyldopa previously caused liver problems.
- Do not use if allergic to any component.
- Do not use with MAO inhibitors.
- Kidney problems may call for smaller doses.
- Older adults may faint more easily and may need lower doses.
- Children’s doses are weight-based.
- It crosses the placenta and appears in breast milk.
Methyldopa overdose
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Too much methyldopa can cause low blood pressure, heavy sedation, weakness, a slow heartbeat, dizziness, and stomach upset such as nausea, vomiting and diarrhea. Treatment is supportive, and recent ingestion may be managed by emptying the stomach. Methyldopa can be removed by dialysis. Seek emergency help right away.
What Methyldopa does in the body
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Methyldopa lowers both lying-down and standing blood pressure. It has no direct effect on the heart and usually keeps cardiac output steady, and in some people it slows the heart rate. It usually does not reduce kidney blood flow, and plasma renin activity may decrease.
How your body processes Methyldopa
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After a dose by mouth, blood pressure drops most at 4 to 6 hours. A steady response usually develops in 12 to 24 hours. Methyldopa is heavily metabolized, and about 70% of the absorbed drug leaves in urine. Its half-life is about 105 minutes, and elimination is essentially complete within 36 hours. Kidney problems slow clearance.
How to store Methyldopa
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Store at 20° to 25°C (68° to 77°F). Protect from light. Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Methyldopa
173 supplements and herbal products have documented interactions with Methyldopa in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 8
- Moderate · 144
- Minor · 21
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Nutrient depletion considerations
Methyldopa has been associated with lower levels of 1 nutrient in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.
Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.
Methyldopa: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Methyldopa — the kind of thing our pharmacy team would talk through with you at the counter.
What is methyldopa for?
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Why do I feel sleepy on it?
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Can I stop it if my blood pressure looks good?
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Do I need blood tests?
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Can I take iron or other medicines with it?
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Is it okay during pregnancy or breastfeeding?
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Is Methyldopa available over the counter?
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When was Methyldopa first available?
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Who makes Methyldopa?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Methyldopa on HelloPharmacist
Methyldopa forms and strengths (how it comes)
Methyldopa is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Tablet
How this form is used
- Methyldopa tablets are labeled to treat high blood pressure (hypertension).
- Methyldopa tablets are taken by mouth, usually in two to four doses a day.
- Methyldopa dosage increases are often started in the evening to reduce sedation.
- Methyldopa dosing is adjusted by your prescriber until blood pressure is controlled.
Methyldopa on the U.S. market: products, makers and brands
How Methyldopa appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
2 companies list 4 Methyldopa product records with the FDA, mostly as tablet; the earliest marketing or approval year on record is 1962. Brand names on the directory include Aldomet; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (2) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
How widely Methyldopa is used (Medicaid data)
A general measure of how commonly Methyldopa is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Methyldopa is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Methyldopa prescribed? Of the 1,601 medications we measure, Methyldopa ranks #1,425 by Medicaid prescriptions — more than 11% of them.
Utilization by Methyldopa product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
methyldopa 250 MG Oral Tablet Most dispensed
Summed across the 2 of 9 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 197956
methyldopa 500 MG Oral Tablet
Summed across the 1 of 7 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 197958
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Methyldopa, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 3 of 16 listed Methyldopa NDCs with Medicaid activity.
Compare Methyldopa products
A representative set of FDA-listed product records for Methyldopa — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 250 mg | Oral | Chartwell RX, LLC | NDA AUTHORIZED GENERIC | View NDC → |
| 500 mg | Oral | Chartwell RX, LLC | NDA AUTHORIZED GENERIC | View NDC → |
| 250 mg | Oral | Rising Pharma Holdings, Inc. | ANDA | View NDC → |
| 500 mg | Oral | Rising Pharma Holdings, Inc. | ANDA | View NDC → |
Showing 4 of 4 products — FDA National Drug Code Directory. See every product, package size and price: browse all 4 Methyldopa NDCs →
Methyldopa side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Methyldopa — a signal of what to watch for, not proof the drug caused it.
The effects most often named in FDA reports that mention Methyldopa are foetal exposure during pregnancy, premature baby, exposure during pregnancy; about 93% of the reports were classed as serious. These are voluntary reports, so they show what people report, not how often it happens.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Methyldopa in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Methyldopa FDA approval history
How Methyldopa went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Methyldopa was first approved by the FDA in 1962 (Brand: ALDOMET · Merck); the first generic version was approved in 1985. It remains available in U.S. pharmacies today.
Source: Drugs@FDA.
Methyldopa recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Methyldopa recalls since July 2021.
✅No Methyldopa recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 6876 3 dose forms · 4 strengths
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Dose form (SCDF) Oral Capsule RxCUI 376259No current FDA listingClinical drug / strength (SCD) 250 MGRxCUI 104357 -
Dose form (SCDF) Oral Suspension RxCUI 372854No current FDA listing -
Dose form (SCDF) Oral Tablet RxCUI 372855In current FDA listings
Look up RxCUI 6876 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Methyldopa supply and shortage status
Whether Methyldopa is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
💵 What Methyldopa costs pharmacies (NADAC benchmark)
The national average invoice price pharmacies pay for the drug itself, from CMS's NADAC survey (data as of Jul 15, 2026). This is a supply-cost benchmark — not a retail price and not what you'd pay at the counter.
| Form | Strength | Pharmacy acquisition benchmark | |
|---|---|---|---|
| Tablet, Film Coated · Oral | 250 mg | $7.50 per tablet | NDC details & price history |
| Tablet · Oral | 250 mg | $7.50 per tablet | NDC details & price history |
Source: CMS National Average Drug Acquisition Cost (NADAC), a survey of retail pharmacy invoice prices. Benchmarks shown are the range across package sizes of a representative product for each form and strength — other manufacturers' products may differ.
Methyldopa brand names
Methyldopa is sold under one brand name in the FDA directory — Aldomet. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Methyldopa: manufacturers and labelers
2 companies list Methyldopa products with the FDA. By number of product records, the largest are Chartwell RX, LLC, Rising Pharma Holdings, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Methyldopa drug class (RxNorm)
Methyldopa belongs to the Central alpha-2 Adrenergic Agonist class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Methyldopa page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Chartwell RX, LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →