Patient Medication Information: uses, side effects, how to take - Methyldopa
What is METHYLDOPA used for?
METHYLDOPA is used in children and adults to treat high blood pressure, (also called hypertension). It can be used by itself, or with other medicines to treat high blood pressure.
How does METHYLDOPA work?
METHYLDOPA works by controlling impulses along certain nerve pathways. As a result, it relaxes and widens blood vessels so that blood passes through them more easily. This helps to lower blood pressure.
What are the ingredients in METHYLDOPA?
Medicinal ingredient: Methyldopa.
Non-medicinal ingredients: Carnauba wax, croscarmellose sodium, magnesium stearate, and microcrystalline cellulose. In addition, the film-coating contains: D&C yellow #10 aluminum lake, ferric oxide yellow, hydroxypropyl methylcellulose, polydextrose, polyethylene glycol, and titanium dioxide.
METHYLDOPA comes in the following dosage forms:
Tablets: 125 mg, 250 mg and 500 mg of methyldopa.
Serious Warnings and Precautions
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Do not use METHYLDOPA if:
- you are allergic to methyldopa or any other ingredients in the formulation.
- you have liver disease, such as hepatitis or cirrhosis.
- you have taken methyldopa in the past and developed liver problems or hemolytic anemia.
- you have or previously had depression.
- you are taking a type of medicine called a ‘monoamine oxidase inhibitor’ (MAOI), typically used to treat depression.
- you have high blood pressure caused by a tumour near your kidney called ‘pheochromocytoma’ or ‘paraganglioma’.
- you have a rare blood disorder called ‘porphyria’.
To help avoid side effects and ensure proper use, talk to your healthcare professional before you take METHYLDOPA. Talk about any health conditions or problems you may have, including if you:
- have any brain problems or nerve damage.
- are going to have a blood transfusion.
- have liver problems.
- are undergoing or plan to have any surgery, that requires an anaesthetic.
- have kidney problems.
- are undergoing dialysis.
are pregnant or plan to become pregnant.
- are breast feeding or plan to breast feed. You should not breast feed while using METHYLDOPA.
- are elderly (65 years of age, or older).
Other warnings you should know about:
Monitoring and Tests: Your healthcare professional may perform blood tests before you start, and periodically during your treatment with METHYLDOPA. These blood tests monitor:
- your liver function.
- your blood count and the presence of antibodies in your blood (Coombs test).
Your healthcare professional will interpret the results of these tests and may continue or stop your treatment with METHYLDOPA.
If you need to give a urine or blood sample for another reason, tell your healthcare professional you are taking METHYLDOPA, as it may affect the results of some types of tests.
Driving and using machinery: METHYLDOPA may make you feel sleepy and less alert. If feel sleepy or less alert, you should not drive or do tasks that require special attention.
Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.
Serious Drug Interactions Serious drug interactions with METHYLDOPA include:
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The following may also interact with METHYLDOPA:
- antihypertensives, medicines typically used to treat high blood pressure.
- lithium, a medicine typically used to treat some types of depression.
- phenothiazines, medicines typically used for mental or emotional disorders (e.g., chlorpromazine).
- tricyclic antidepressants, medicines typically used to treat depression.
- sympathomimetics, medicines used to increase blood pressure, open airways, and relieve congestion.
- iron and supplements containing iron (e.g., multivitamins with minerals).
- anaesthetics used during surgery.
Ask your healthcare professional if you are unsure.
How to take METHYLDOPA:
- Take METHYLDOPA exactly as your healthcare professional has told you to.
- Your healthcare professional will tell you when to take your dose of METHYLDOPA.
Usual dose:
Your healthcare professional will decide the right dose of METHYLDOPA for you. This may depend on your age, weight, health, and how you respond to METHYLDOPA.
Children (17 years of age or younger): Your healthcare professional will decide the dose based on the weight of the child.
- The usual starting dose is 10 mg for each kg of body weight each day.
- This dose is taken in two to four doses during the day.
- Your healthcare professional may then change the dose, depending on how the child responds.
Adults (18 to 64 years of age):
- The usual starting dose for the first two days is 250 mg two or three times a day.
- Your healthcare professional may then change your dose depending on how you respond.
Elderly (65 years of age or older):
- The usual starting dose is 125 mg two times a day.
- Your healthcare professional may then slowly increase the dose depending on how you respond.
- The maximum daily dose is 2000 mg a day.
Overdose:
If you take too many tablets, you may feel light-headed and dizzy or you may faint. You may also feel very drowsy, weak, may have a slow heart rate, be constipated, have abdominal bloating, gas in the stomach or bowel, diarrhoea, nausea or vomiting.
| If you think you, or a person you are caring for, have taken too much METHYLDOPA, contact a healthcare professional, hospital emergency department, regional poison control centre or Health Canada’s toll-free number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms. |
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Missed Dose:
If you miss a dose, skip the missed dose and take your next dose at the regular scheduled time. Do NOT take a double dose to make up for the missed dose.
What are possible side effects from using METHYLDOPA?
These are not all the possible side effects you may have when taking METHYLDOPA. If you experience any side effects not listed here, tell your healthcare professional.
Side effects may include:
- nausea
- vomiting
- feeling bloated
- gas in stomach
- diarrhea
- dry mouth
- sore or black tongue
- weakness
- joint stiffness, muscle aches and/or pain
- fever
- drowsiness
- headache
- dizziness, light-headedness
- numbness or burning feeling
- altered mental status
- nightmares
- impotence, decreased sexual desire (libido)
- stuffy nose
- skin rash
- irregular menstrual cycle or absence of periods
- unexpected milk production (lactation)
Serious side effects and what to do about them
| Symptom / effect | Talk to your healthcare professional | Stop taking drug and get immediate medical help | |
|---|---|---|---|
| Only if severe | In all cases | ||
| UNKNOWN FREQUENCY | |||
| Angina (not enough oxygen to the heart muscle): discomfort in the shoulder, arm, back, throat, jaw or teeth, or pain or pressure in the chest. | √ | ||
| Blood disorders (low white blood cell, red blood cell, or platelet count): feeling tired or weak, pale skin, bruising or bleeding for longer than usual if you hurt yourself, fever, or chills. | √ | ||
| Bradycardia (abnormally slow heartbeat) | √ | ||
| Brain disorder symptoms: severe and sudden headache, paralysis of one side of the body, slurred speech, unconsciousness, memory loss, parkinsonism (tremors, slow movement, impaired speech, or muscle stiffness), or Bells Palsy (facial muscle weakness or paralysis, involuntary twitching or writhing). | √ | ||
| Colitis (inflammation of the large intestine): abdominal pain, blood in the stool, fatigue, fever, or weight loss. | √ | ||
| Depression (sad mood that won’t go away): difficulty sleeping or sleeping too much, changes in appetite or weight, feelings of worthlessness, guilt, regret, helplessness or hopelessness, withdrawal from social situations, family, gatherings and activities with friends, reduced libido (sex drive), or thoughts of death or suicide. | √ | ||
| Edema and angioedema (unusual swelling of the arms, hands, legs, feet and ankles, face, airway passages, or tissue under the skin): weight gain (water retention), difficulty breathing, swollen face, hands and feet, tongue, or throat. | √ | ||
| Glossodynia (burning mouth syndrome): hot feeling or burning in the tongue, lips, and areas of your mouth, soreness, altered taste, or dryness of the tongue. | √ | ||
| Gynecomastia: breast enlargement in men and/or women, which may cause lactation. | √ | ||
Serious side effects and what to do about them
| Symptom / effect | Talk to your healthcare professional | Stop taking drug and get immediate medical help | |
|---|---|---|---|
| Only if severe | In all cases | ||
| Heart problems: chest pain, discomfort, or pressure, shortness of breath, fatigue, swelling in the legs, ankles, or feet, abnormally rapid, or irregular heartbeat, dizziness, feeling lightheaded, fainting, swelling, weight gain, bloating, palpitations, coughing or wheezing, or pain in the upper abdomen. | √ | ||
| Hemolytic anemia (breakdown of red blood cells): pale skin, feeling tired, feeling weak, dizziness, fainting, thirst, or rapid breathing. | √ | ||
| Hypotension (low blood pressure): dizziness, fainting, light-headedness, blurred vision, nausea, vomiting, or fatigue (may occur when you go from lying or sitting to standing up). | √ | ||
| Liver problems: yellowing of the skin or eyes (jaundice), dark urine and pale stools, abdominal pain, nausea, vomiting, loss of appetite, fatigue, fever, or itchiness. | √ | ||
| Lupus-like syndrome (symptoms that are similar to a condition called ‘lupus’): rashes, joint or muscle pain, fatigue, fever, chest pain, mouth sores, or increased sensitivity to light. | √ | ||
| Myocarditis (inflammation of the heart muscle and lining around the heart): abnormal heartbeat, chest pain that may resemble a heart attack, fatigue, fever and other signs of infection including headache, muscle aches, sore throat, diarrhea, or rashes, joint pain or swelling, leg swelling, or shortness of breath. | √ | ||
| Pancreatitis (inflammation of the pancreas): upper abdominal pain, fever, rapid heart beat, nausea, vomiting, or tenderness when touching the abdomen. | √ | ||
| Psychosis (disconnect from reality): hallucinations, delusions (false beliefs), disorganized thinking, confusion, agitation, or social withdrawal. | √ | ||
| Sialadenitis (infection of a salivary gland): swelling, pain, redness or tenderness of the gland, fever, or chills. | √ | ||
| Skin reactions: itchy skin, dry skin, small bumps on the skin, rash, hives, redness, blistering of the skin, or | √ | ||
Serious side effects and what to do about them
| Symptom / effect | Talk to your healthcare professional | Stop taking drug and get immediate medical help | |
|---|---|---|---|
| Only if severe | In all cases | ||
| peeling of the skin. | |||
| Toxic epidermal necrolysis (TEN) (a serious skin reaction): redness, blistering, rash, and/or peeling of large areas of the skin, sores, swelling, or crusting on the eyes, mouth, and vagina. | √ | ||
| Vasculitis (inflammation of the blood vessels): fatigue, weight loss, trouble breathing, coughing, numbness, tingling, fever, headache, weakness, joint pain, or stomach pain. | √ | ||
If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.
Reporting Side Effects
You can report any suspected side effects associated with the use of health products to Health Canada by:
NOTE: Contact your healthcare professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice. |
Storage:
Store at room temperature 15°C to 30°C.
Keep out of reach and sight of children.
If you want more information about METHYLDOPA:
- Talk to your healthcare professional.
- Find the full Product Monograph that is prepared for healthcare professionals and includes this Patient Medication Information by visiting the Health Canada website (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html); the manufacturer’s website (https://www.aapharma.ca/en/), or by calling 1-877-998-9097.
Date of Authorization: April 10, 2025