Penicillamine Ferrous sulfate

Osman MA, Patel RB, Schnna A, Snndstrom WR, Welling PG. Reduction in oral penicillamine absorption by food, antacid, and ferrous sulfate. CUn Pharmacol Ther 1983 33(4) 465-70. 

B. Several drugs (eg, antacids and ferrous sulfate) and food can substantially reduce gastrointestinal absorption of penicillamine. 

A two-thirds reduction in absorption has been described in 6 other subjects given penicillamine 500 mg and ferrous sulfate 300 mg. Other studies confirm this interaction. There is also evidence that the withdrawal of iron from patients stabilised on penicillamine can lead to the development of toxicity (nephropathy) unless the penicillamine dosage is reduced. ... 

An established and elinieally important interaetion. For maximal absorption give the iron at least 2 hours after the penicillamine. This should reduce their admixture in the gut. Do not withdraw iron suddenly from patients stabilised on penicillamine because the marked increase in absorption that follows may precipitate penicillamine toxicity. The toxic effects of penicillamine seem to be dependent on the size of the dose and possibly also related to the rate at which the dosage is increased. Only ferrous sulfate and fumarate have been studied but other iron compounds would be expected to interact similarly. 

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