Ferrous Sulfate and Methyldopa Interaction
Drug interaction information between Ferrous Sulfate and Methyldopa.
Ferrous Sulfate and Methyldopa have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Ferrous Sulfate and Methyldopa. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Iron supplements can prevent the body from absorbing the blood pressure medicine correctly. This means the medicine may not work well enough to control your blood pressure.
FDA Label Information
Several studies demonstrate a decrease in the bioavailability of methyldopa when it is ingested with ferrous sulfate or ferrous gluconate. Coadministration of methyldopa with ferrous sulfate or ferrous gluconate is not recommended.
Methyldopa Also Interacts With
- Carbidopa/Levodopa moderate
- Tranylcypromine moderate
- Lithium minor
- Colestipol minor
- Enalapril minor
Frequently Asked Questions
What SPL severity band is on file for Ferrous Sulfate + Methyldopa?
Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Methyldopa has 7 labeled pairs on file vs Ferrous Sulfate's 2. In the moderate band specifically: Ferrous Sulfate has 1; Methyldopa has 3 (also Carbidopa/Levodopa, Tranylcypromine).
What mechanism field is on file for Ferrous Sulfate and Methyldopa?
Iron supplements can prevent the body from absorbing the blood pressure medicine correctly. This means the medicine may not work well enough to control your blood pressure.
Methyldopa's labeled portfolio outnumbers Ferrous Sulfate
SPL source-record counts only. This page's band is moderate · classes on file: Ferrous Sulfate (Iron Supplement); Methyldopa (Central Alpha-2 Agonist).
0 major · 1 moderate · 1 minor · 2 total
Ferrous Sulfate has no other moderate-band peer in this dataset besides Methyldopa.
0 major · 3 moderate · 4 minor · 7 total
- Other moderate peers for Methyldopa
- Carbidopa/Levodopa
- Tranylcypromine
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.