Drug Interaction Report

Methyldopa and Amitriptyline: Interaction Details

A pharmacist-reviewed analysis of the Methyldopa and Amitriptyline interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Amitriptyline

Elavil
+

Methyldopa

Aldomet®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Minor
Usually limited clinical impact.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 53 documented Methyldopa interactions, 3 are rated minor — including this one.
Onset
delayed
Evidence
theoretical
Severity
Minor

What happens

Blood pressure elevation

Interaction Deep Dive

The majority of patients taking methyldopa and a tricyclic antidepressant show no adverse hypertensive effects, although loss of antihypertensive efficacy has been reported1.

Why it happens (mechanism)

Unknown

Literature reports

1 report — tap to read

a) A hypertensive patient who was previously well controlled on methyldopa developed blood pressure elevation when amitriptyline therapy was initiated 1. Following 10 days of therapy, the patient became agitated, developed a fine hand tremor, and "felt like a different person". However, these adverse CNS effects have been reported with both drugs and there is no evidence they were due to an adverse interaction between methyldopa and tricyclic antidepressants 2345.

Common questions

Can I take Methyldopa and Amitriptyline together?

Blood pressure elevation Always confirm with your pharmacist or prescriber before making any change.

How serious is the Methyldopa and Amitriptyline interaction?

It is rated minor. Usually limited clinical impact.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Methyldopa or Amitriptyline need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there anything you'd monitor while I'm on both?

References (5)

  1. White AG: Methyldopa and amitriptyline (letter). Lancet 1965; 2:441. PubMed
  2. Paykel ES: Hallucinosis on combined methyldopa and pargyline. Br Med J 1966; 1:803. DOI
  3. Davies RK, Tucker GJ, Harrow M, et al: Confusional episodes and antidepressant medication. Am J Psychiatry 1971; 128:95-99. PubMed
  4. Anon: Boston Collaborative Drug Surveillance Program: Adverse reactions to the tricyclic drugs. Lancet 1972; 1:529.
  5. Reid JL, Porsius AJ, Zamboulis C, et al: The effects of desmethylimipramine on the pharmacological actions of alpha methyldopa in man. Eur J Clin Pharmacol 1979; 16:75-80. DOI
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Amitriptyline

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Methyldopa

Keep reading about Methyldopa

All Methyldopa interactions (53) Methyldopa drug information
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Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Amitriptyline + 1,4-butanediol Activated Charcoal American Hellebore Arsenic Beer Cesium Ephedra Gamma-hydroxybutyrate (ghb) + 288 more
Methyldopa + Activated Charcoal American Hellebore American Mistletoe Beer Cowhage Siberian Cocklebur Tyramine Wine + 165 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.