Name: Aldomet

Can methyldopa cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the common ones associated with methyldopa. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common methyldopa side-effects
What can I do if I experience this?
Feeling sleepy, weak, or tiredThis can happen during the first few days of treatment in particular. Do not drive or use tools or machines while affected. Do not drink alcohol
HeadacheAsk your pharmacist to recommend a suitable painkiller

Important: if you develop a high temperature which you can't explain, or if you notice any yellowing of your skin or the whites of your eyes (jaundice), speak with your doctor as soon as possible. Occasionally, some people taking methyldopa have had blood or liver problems and your doctor will want you to have a blood test to check for these.

If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for further advice.

Pregnancy & Lactation

Pregnancy Category: B

Lactation: distributed in breast milk but not in clinically significant amounts; compatible w/ breastfeeding

Pregnancy Categories

A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA:Information not available.

What should I discuss with my healthcare provider before taking Aldomet (methyldopa)?

You should not take this medication if you are allergic to methyldopa, or if you have:

  • liver disease (especially cirrhosis); or

  • a history of liver problems caused by taking methyldopa.

Do not use methyldopa if you have used an MAO inhibitor such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam, Zelapar), or tranylcypromine (Parnate) in the last 14 days. A dangerous drug interaction could occur, leading to serious side effects.

To make sure you can safely take methyldopa, tell your doctor if you have any of these other conditions:

  • kidney disease (or if you are on dialysis);

  • a history of liver disease;

  • heart disease, angina (chest pain); or

  • a history of heart attack or stroke.

FDA pregnancy category B. Methyldopa is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Methyldopa passes into breast milk. It is not known whether methyldopa will harm a nursing infant. Do not take this medication without first talking to your doctor if you are breast-feeding a baby.

Before Using Aldomet

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Although there is no specific information comparing use of methyldopa in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in adults.


Dizziness or lightheadedness and drowsiness may be more likely to occur in the elderly, who are more sensitive to the effects of methyldopa.


Pregnancy Category Explanation
All Trimesters B Animal studies have revealed no evidence of harm to the fetus, however, there are no adequate studies in pregnant women OR animal studies have shown an adverse effect, but adequate studies in pregnant women have failed to demonstrate a risk to the fetus.

Breast Feeding

Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Brofaromine
  • Clorgyline
  • Furazolidone
  • Iproniazid
  • Isocarboxazid
  • Lazabemide
  • Linezolid
  • Moclobemide
  • Nialamide
  • Pargyline
  • Phenelzine
  • Procarbazine
  • Rasagiline
  • Selegiline
  • Toloxatone
  • Tranylcypromine

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Entacapone
  • Pseudoephedrine

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Alprenolol
  • Bisoprolol
  • Ferric Ammonium Citrate
  • Haloperidol
  • Iron
  • Phenylpropanolamine
  • Sotalol
  • Timolol

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Angina (chest pain) or
  • Parkinson's disease—Methyldopa may make these conditions worse
  • Kidney disease or
  • Liver disease—Effects of methyldopa may be increased because of slower removal from the body
  • Mental depression (history of)—Methyldopa can cause mental depression
  • Pheochromocytoma—Methyldopa may interfere with tests for the condition; in addition, there have been reports of increased blood pressure
  • If you have taken methyldopa in the past and developed liver problems

Precautions While Using Aldomet

It is important that your doctor check your progress at regular visits to make sure that this medicine is working properly.

Do not take other medicines unless they have been discussed with your doctor. This especially includes over-the-counter (nonprescription) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.

If you have a fever and there seems to be no reason for it, check with your doctor. This is especially important during the first few weeks you take methyldopa, since fever may be a sign of a serious reaction to this medicine.

Before having any kind of surgery (including dental surgery) or emergency treatment, make sure the medical doctor or dentist in charge knows that you are taking this medicine.

Methyldopa may cause some people to become drowsy or less alert than they are normally. This is more likely to happen when you begin to take it or when you increase the amount of medicine you are taking. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.

Dizziness, lightheadedness, or fainting may occur, especially when you get up from a lying or sitting position. Getting up slowly may help, but if the problem continues or gets worse, check with your doctor.

Methyldopa may cause dryness of the mouth. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.

Tell the doctor in charge that you are taking this medicine before you have any medical tests. The results of some tests may be affected by this medicine.

Side effects

Sedation, usually transient, may occur during the initial period of therapy or whenever the dose is increased. Headache, asthenia, or weakness may be noted as early and transient symptoms. However, significant adverse effects due to ALDOMET (methyldopa) have been infrequent and this agent usually is well tolerated.

The following adverse reactions have been reported and, within each category, are listed in order of decreasing severity.

Cardiovascular: Aggravation of angina pectoris, congestive heart failure, prolonged carotid sinus hypersensitivity, orthostatic hypotension (decrease daily dosage), edema or weight gain, bradycardia.

Digestive: Pancreatitis, colitis, vomiting, diarrhea, sialadenitis, sore or "black" tongue, nausea, constipation, distension, flatus, dryness of mouth.

Endocrine: Hyperprolactinemia.

Hematologic: Bone marrow depression, leukopenia, granulocytopenia, thrombocytopenia, hemolytic anemia; positive tests for antinuclear antibody, LE cells, and rheumatoid factor, positive Coombs test.

Hepatic: Liver disorders including hepatitis, jaundice, abnormal liver function tests (see WARNINGS).

Hypersensitivity: Myocarditis, pericarditis, vasculitis, lupus-like syndrome, drug-related fever, eosinophilia.

Nervous System/Psychiatric: Parkinsonism, Bell's palsy, decreased mental acuity, involuntary choreoathetotic movements, symptoms of cerebrovascular insufficiency, psychic disturbances including nightmares and reversible mild psychoses or depression, headache, sedation, asthenia or weakness, dizziness, lightheadedness, paresthesias.

Metabolic: Rise in BUN.

Musculoskeletal: Arthralgia, with or without joint swelling; myalgia.

Respiratory: Nasal stuffiness.

Skin: Toxic epidermal necrolysis, rash.

Urogenital: Amenorrhea, breast enlargement, gynecomastia, lactation, impotence, decreased libido.

Read the entire FDA prescribing information for Aldomet (Methyldopa)

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Liver Dose Adjustments

Methyldopa is contraindicated in patients with active hepatic disease, such as acute hepatitis and active cirrhosis.

Dose Adjustments

CrCl < 15 mL/min: The dosage interval should be every 12 to 24 hours.

CrCl 15-50 mL/min: The dosage interval should be every 8 to 12 hours.


Methyldopa is slightly dialyzable (5%-20%).

Methyldopa Pregnancy Warnings

Oral methyldopa has been assigned to pregnancy category B and the intravenous form methyldopate hydrochloride (the ethyl ester of methyldopa) has been assigned to category C by the FDA. Animal studies have failed to reveal evidence of teratogenicity or fetotoxicity. There are no controlled data in human pregnancy. Methyldopa is only recommended for use during pregnancy when benefit outweighs risk.

Methyldopa crosses the placenta, and may cause mild hypotension in neonates of treated mothers. Because it has been safely and successfully used to treat hypertension during pregnancy, some experts consider it to be the drug of choice for the treatment of nonemergent hypertension during pregnancy. Of 3,248 children with any malformation related to a diuretic or a drug taken for a cardiovascular disorder from a population of 50,282 mother-child pairs in the Collaborative Perinatal Project, only one case associated with methyldopa was monitored, and no abnormalities were observed. An infant born with congenital heart disease, esophageal atresia, an absent kidney, and hypospadias whose mother received methyldopa throughout her pregnancy and clomiphene in the first trimester has been reported. In one study a decrease in mean head circumference of 202 neonates of mothers who were begun on methyldopa during gestation weeks 16 and 20 has been reported. Long-term follow-up of 98% of these children has not revealed abnormalities, and the development delay commonly seen in children of hypertensive mothers was less in children whose mothers received methyldopa than in children of untreated mothers. A review of 1,157 hypertensive pregnancies has revealed no evidence of teratogenicity or fetotoxicity associated with methyldopa. The Michigan Medicaid surveillance study showed no association between the use of methyldopa and congenital defects (written communication, Franz Rosa, MD, Food and Drug Administration, 1994). This report is a summary of information from two studies, one in which 120 of 104,000 pregnant women from 1980 to 1983, and one in which 242 of 229,101 pregnant women from 1985 to 1992 received methyldopa during pregnancy. Eight and 11 total defects were observed in these studies, respectively (8 and 10 were expected, respectively). The one instance each of cardiovascular defect, cleft palate, and polydactyly in the second study did not achieve statistical significance. These data do not support an association between methyldopa and congenital defects. The various features of the fetal heart rate pattern, as evaluated in a controlled trial by computerized cardiotocography in human pregnancy, were not influenced by methyldopa 250 mg three times a day in 19 women with preeclampsia.