Methyldopa | Side Effects, Dosage, Uses & More
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Generic Name:

methyldopa, Oral tablet

All Brands

  • Aldomet (Discontinued)
A discontinued drug is a drug that has been taken off the market due to safety issues, shortage of raw materials, or low market demand.
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Highlights for methyldopa

Oral tablet
1

Methyldopa is used to treat hypertension (high blood pressure).  

2

The usual starting dose of methyldopa is 250 mg, taken by mouth, two to three times per day in the first 48 hours. If your blood pressure is still high after 2–3 days, your doctor may increase your dose up to a maximum of 3,000 mg per day.

3

Methyldopa may cause temporary drowsiness. This usually occurs when you first start taking the drug or when your doctor increases your dose.

4

Common side effects of methyldopa include drowsiness, headache, a lack of energy, and weakness. Your hands and feet may swell (edema), or you may gain weight while taking this drug. You may need a water pill (called a diuretic) to help control the swelling and weight gain. You may need to stop taking this drug if the edema gets worse or you develop heart failure.

IMPORTANT INFORMATION

liver disease

Liver problems that can lead to death are possible when taking this drug. Never use methyldopa if you have liver disease, including acute hepatitis or active cirrhosis.

Monoamine oxidase inhibitors

Don’t take methyldopa if you’re taking types of drugs called monoamine oxidase inhibitors. Examples include isocarboxazid, phenelzine, linezolid, and tranylcypromine.

Blood disorder

Methyldopa may be associated with a deadly type of blood disorder in which your red blood cells are destroyed (hemolytic anemia). This disorder can lead to death if it isn’t caught in time.

What is methyldopa?

Methyldopa is a prescription drug that’s available in oral tablets in generic form only. You may take methyldopa by itself or in combination with other drugs to treat high blood pressure.

Why it's used

Methyldopa is used to treat high blood pressure. Lowering your blood pressure will help reduce your chance of having a stroke or heart attack.

How it works

Methyldopa belongs to a class of drugs called centrally acting antiadrenergics.

More Details

How it works

Methyldopa belongs to a class of drugs called centrally acting antiadrenergics. A class of drugs is a group of medications that work in a similar way. They’re often used to treat similar conditions.

Your brain normally sends signals to your blood vessels that cause the vessels to narrow. This increases your blood pressure. Methyldopa prevents your brain from sending these signals. This helps to prevent your blood pressure from rising.

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methyldopa Side Effects

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More Common Side Effects

The more common side effects that can occur with methyldopa include:

  • drowsiness

  • headache

  • lack of energy

  • weakness

  • dizziness

  • lightheadedness

  • fainting

  • nausea or vomiting

If these effects are mild, they may disappear within a few days or a couple of weeks. If they’re more severe or don’t disappear, talk to your doctor or pharmacist.

Serious Side Effects

Call your doctor right away if you have serious side effects. Call 9-1-1 if your symptoms feel life threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • Heart problems. Symptoms include:

    • worsening angina (chest pain)
    • swelling of your hands, feet, legs, or ankles
    • weight gain
    • shortness of breath
    • irregular or pounding heartbeat
  • Low red blood cells. Symptoms include:

    • extreme tiredness
    • lightheadedness
    • shortness of breath
    • pale skin 
  • Low white blood cells. Symptoms include:

    • fever
    • cold symptoms like a runny nose or sore throat that don’t go away
    • flu symptoms like body aches and tiredness 
  • Low platelets. Symptoms include:

    • cuts or wounds that don’t stop bleeding 
  • Liver problems. Symptoms include:

    • yellowing of your skin and the whites of your eyes
    • nausea
    • not wanting to eat
    • dark-colored urine
    • tiredness
  • Allergic reactions. Symptoms include:

    • fever
    • sharp chest pain
    • rash
    • joint pains
    • tiredness
    • trouble breathing or swallowing
  • Skin problems. Symptoms include:

    • red skin
    • peeling skin
    • blistering skin 
Pharmacist's Advice
Clinical Associate Professor, University of Illinois at Chicago College of Pharmacy

Methyldopa may cause temporary drowsiness. This usually occurs when you first start taking the drug. It may also happen if your doctor increases your dose.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
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methyldopa May Interact with Other Medications

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Methyldopa can interact with other medications, herbs, or vitamins you might be taking. An interaction is when a substance changes the way a drug works. This can be harmful or cause the drugs that you take to not work as well. To help prevent interactions, your doctor should manage all of your medications carefully. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Alcohol interaction

Drinking alcohol while taking methyldopa may increase the effect of this drug. It may slow your reflexes, make you sleepy, or reduce your ability to make good decisions.

Medications that might interact with this drug

Anesthetics

If you have surgery, your doctor may need to use anesthetics so you don’t feel pain. Your doctor may need to use lower doses of anesthetics if you take methyldopa. Anesthetics also lower your blood pressure. If you take methyldopa and receive regular doses of anesthetics, your blood pressure may drop too low (hypotension).

Bipolar disorder drug

Using methyldopa with lithium (a bipolar disorder drug) can cause lithium to rise to toxic levels in your body.

Other blood pressure drugs

Taking methyldopa with any other drugs that also lower your blood pressure can increase your risk of dangerously low blood pressure (hypotension). Examples of these drugs include:

  • angiotensin-converting enzyme (ACE) inhibitors, such as:
    • benazepril
    • captopril
    • cilazapril
    • enalapril
    • enalaprilat
    • fosinopril
    • imidapril
    • moexipril
    • perindopril
    • quinapril
    • ramipril
    • trandolapril
  • angiotensin receptor blockers (ARBs), such as:
    • irbesartan
    • losartan
    • olmesartan
    • telmisartan
    • valsartan
  • beta-blockers, such as:
    • acebutolol
    • arotinolol
    • atenolol
    • betaxolol
    • bisoprolol
    • esmolol
    • metoprolol
    • nadolol
    • nebivolol
    • penbutolol
    • pindolol
    • propranolol
    • timolol (systemic)
  • calcium channel blockers, such as:
    • amlodipine
    • felodipine
    • nicardipine
    • nifedipine
  • direct renin inhibitors, such as:
    • aliskiren
  • loop diuretics, such as:
    • bumetanide
    • furosemide
    • indapamide
    • torsemide
  • potassium-sparing diuretics, such as:
    • eplerenone
    • spironolactone
    • triamterene
  • thiazide diuretics, such as:
    • chlorothiazide
    • chlorthalidone
    • hydrochlorothiazide
    • methyclothiazide
    • metolazone

Depression drugs

Certain depression drugs called monoamine oxidase (MAO) inhibitors, shouldn’t be used with methyldopa. Taking these drugs with methyldopa can cause your blood pressure to rise to levels that are dangerous. This is known as hypertensive crisis. It’s a medical emergency. Examples of MAO inhibitors include:

  • isocarboxazid
  • phenelzine
  • tranylcypromine 

Iron supplements

Don’t use iron supplements if you take methyldopa. Taking iron supplements may decrease the amount of methyldopa in your body. This may make methyldopa less effective at lowering your high blood pressure.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Methyldopa warnings
liver disease
People with liver disease

You shouldn’t take this drug if you have or have had liver disease. Methyldopa can cause severe liver damage. Your doctor will do some tests to check how well your liver is working during the first 6 to 12 weeks after starting this medication.

kidney disease
People with kidney disease

Methyldopa is removed from your body by your kidneys. If your kidneys aren’t working well, more of the drug may stay in your body longer and put you at risk for side effects. Talk to your doctor about any kidney problems you have or have had.

pregnant women
Pregnant women

Methyldopa is a category B pregnancy drug. That means two things:

  1. Research in animals hasn’t shown a risk to the fetus when the mother takes the drug.
  2. There aren’t enough studies done in humans to show if the drug poses a risk to the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. Animal studies don’t always predict the way humans would respond. Therefore, this drug should only be used in pregnancy if clearly needed. 

Women who are breast-feeding

Methyldopa passes into breast milk. You and your doctor should talk about whether you should take methyldopa if you wish to breast-feed.

allergies
Allergies

Methyldopa can cause a severe allergic reaction, with the following symptoms:

  • trouble breathing or swallowing
  • swelling of your throat or tongue
  • hives

If you have an allergic reaction, call your doctor or local poison control center right away. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

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How to Take methyldopa (Dosage)

Oral tablet

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Hypertension

Generic: methyldopa

Form: Oral tablet
Strengths: 250 mg, 500 mg
Adult dosage (ages 18–64 years)
  • The usual starting dose of methyldopa is 250 mg, by mouth, two to three times per day in evenly divided doses.
  • If your blood pressure is still high after 3 days, your doctor may increase your dose up to a maximum of 3,000 mg per day.
Child dosage (ages 0–17 years)
  • The usual starting dose is 10 mg per kilogram of body weight per day, given in two to four evenly divided doses.
  • The maximum dose is 65 mg per kilogram, or 3 grams daily, whichever is less.
Senior dosage (ages 65 years and older)

Older adults may process drugs more slowly. A normal adult dose may cause levels of the drug to be higher than normal in older people. Older adults may be more likely to faint or lose consciousness while taking this drug. You may need a lower dose or you may need a different schedule.

Special considerations

If you have poor kidney function, your doctor might adjust your dose:

  • CrCL (creatinine clearance) greater than 50 mL/min: Dosing every 8 hours.
  • CrCl 10–50 mL: Dosing every 8–12 hours.
  • CrCL less than 10: Dosing every 12–24 hours.

Warnings

You may become tolerant to methyldopa between the second and third month of treatment. This means you may need more of the drug to get the same results. Your doctor may choose to either increase your dose or add a water pill (diuretic) to help get your blood pressure back under control.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Clinical Associate Professor, University of Illinois at Chicago College of Pharmacy

If you stop taking the drug suddenly or don’t take it at all

Your blood pressure won’t be controlled. You’ll be at higher risk of a stroke or heart attack.

If you miss doses or don’t take the drug on schedule

Your medication may not work as well or may stop working completely. For this drug to work well, a certain amount needs to be in your body at all times.

If you take too much

You could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include:

  • severe drop in blood pressure
  • weakness
  • lower heart rate
  • dizziness
  • lightheadedness
  • vomiting
  • diarrhea or constipation

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room right away. 

What to do if you miss a dose

If you forget to take your dose, take it as soon as you remember. If you remember just a few hours before the time for your next dose, only take one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.

How to tell if the drug is working

You may not notice a change, but your blood pressure should decrease. This can be seen when you measure your blood pressure with a blood pressure monitor. Your doctor will also monitor your blood pressure to make sure methyldopa is working for you.

Methyldopa is used for long-term treatment.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be better for you than others. Talk to your doctor about other drugs that may work for you.

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How Much Does methyldopa Cost?

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These prices represent the lowest priced national pharmacies for methyldopa on GoodRx. They may be lower than your insurance.

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Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on September 23, 2015

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
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