Levodopa Ferrous sulfate

Drugs that may affect methyidopa include levodopa, nonselective beta-blockers (eg, propranolol), and ferrous sulfate or gluconate. 

Ferrous sulfate can reduce the bioavailability of levodopa and carbidopa, and may possibly reduce the control of Parkinson s disease. 

A study in 9 patients with Parkinson s disease found that a single 325-mg dose of ferrous sulfate reduced the AUC of levodopa by 30% and reduced the AUC of carbidopa by more than 75%. There was a trend towards an increase in disability, suggesting a worsening of disease, but this did not reach statistical significance. Some, but not all of the patients had some deterioration in the control of their disease ... 

Campbell NRC, Hasinoff B. Ferrous sulfate reduces levodopa bioavailability chelation as a possible mechanism. ClinPharmacol Ther 9%9) 45, 220-5. 

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