Methyldopa: Important Information for Patients

Page content

Methyldopa, the generic version of Aldomet, is a medication used, either in combination with other medications or alone, to treat high blood pressure. Lowering high blood pressure helps to reduce the risk of heart attacks, strokes, and kidney problems. It works to lower blood pressure by blocking certain natural chemical, such as norepinephrine and epinephrine, that can cause blood pressure to be high.

How is this Medication Used?

Patients will take this medications two to four times a day, as their doctor prescribes, with or without food. It can take a several weeks before it is known if this medication is working to lower the patient’s blood pressure. Most patients will begin at a low dose and their doctor will slowly increase the dose until the best dosage for the patient is reached. The very first dose should be taken at bedtime, as well as the first time a new dose is taken, to prevent fainting or dizziness.

Side Effects

When this medication is first started, or when a dose increase is given, dizziness, headache, weakness, nasal congestion, and drowsiness can occur. The serious, but rare side effects include:

  • Feet and ankle swelling
  • Abnormal bleeding or bruising
  • Joint and muscle aches
  • Signs of infection
  • Rapid or unexpected weight gain
  • Involuntary movements
  • Mood or mental changes
  • Fast/slow/irregular heartbeat
  • Chest pain
  • Persistent nausea
  • Dark urine
  • Abdominal pain
  • Yellowing of eyes or skin

Though rare, this medication has the potential of increasing prolactin levels in the body. This can cause females to experience stopped or missing periods, unwanted breast milk, or trouble getting pregnant. This can cause men to experience reduced sexual ability, enlarged breasts, or inability to produce sperm. If any of these symptoms occur, the patient should alert their doctor as soon as possible.


Methyldopa and certain medical conditions just do not mix well. These include:

  • Certain allergies
  • Low red blood cell count
  • Heart failure
  • Liver failure
  • Pheochromocytoma
  • Certain genetic conditions
  • Transient ischemic attack/stroke
  • Kidney failure
  • Parkinson’s disease
  • Liver diseases

Drug Interactions

This medication cannot be taken with certain other medications. Such medications include:

  • MAO inhibitors
  • Entacapone
  • Lithium
  • Other blood pressure medications
  • Levodopa
  • Iron products
  • Certain antihistamines
  • Anxiety medications
  • Muscle relaxers
  • Sleep medications
  • Psychiatric medications
  • Anti-seizure medications
  • Narcotic pain medications
  • Caffeine

Warnings and Precautions

Several warnings are associated with this medication. This medication is not known to harm a breastfeeding baby, but all breastfeeding women should talk to their doctor before breastfeeding. Women who are pregnant should consult their physician because methyldopa and pregnancy may not interact well. Before have dental work or surgery, patients should tell their health care provider they are taking this medication.

Alcoholic beverages should be limited. Those who use heavy machinery or perform dangerous tasks should exercise caution.

As a patient ages, their kidney function declines. Since the kidneys remove this medication, those who are elderly can be more sensitive to this medication’s effects, specifically trouble concentrating, dizziness, and memory problems.


RxList. (2010). Aldomet. Retrieved on September 7, 2010 from RxList: (2010). Aldomet. Retrieved on September 7, 2010 from