Levodopa/Iron Salts, Oral Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

When these two medicines are taken together, the absorption of levodopa may decrease.

What might happen:

The effects of your levodopa may decrease and cause an increase in your symptoms of Parkinsonism.

What you should do about this interaction:

Contact your healthcare professionals (e.g. doctor or pharmacist) about taking these two medicines together. They may already be aware of this interaction and may be monitoring you for it. If your doctor prescribes these medicines together, it may be necessary to separate the times that you take each medicine. If you experience an increase in your symptoms of Parkinsonism, contact your doctor. Your dose of levodopa may need adjusting. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Campbell NR, Hasinoff B. Ferrous sulfate reduces levodopa bioavailability: chelation as a possible mechanism. Clin Pharmacol Ther 1989 Mar; 45(3):220-5.
  • 2.Campbell NR, Rankine D, Goodridge AE, Hasinoff BB, Kara M. Sinemet-ferrous sulphate interaction in patients with Parkinson's disease. Br J Clin Pharmacol 1990 Oct;30(4):599-605.