d-Penicillamine (Cuprimine®, Depen®)

D-penicillamine can control joint inflammation in people with arthritis when other agents fail. In scleroderma patients, it also may be helpful in controlling progressive skin thickening and lung inflammation.

The tablets consist of scored 250 mg preparations, which can be cut in half for more gradual dose adjustments. It is important to slowly increase the dose since more rapid increases more commonly can cause side effects. For arthritis, the usual ultimate dose is 500 to 1,000 mg per day. Scleroderma patients may require 750 to 1,500 mg daily.

• Skin rash, usually red, hive-like and itchy.
• Stomach or intestinal upset bothers some people. Occasionally some people complain of a metallic taste in mouth.
• Decreased white blood cell, platelet or red blood cell counts rarely occur. These usually return to normal when the medicine is stopped, but very rarely may be more serious.
• Increased urine protein excretion, which usually occurs without symptoms and fortunately is rare.
• Rarely, penicillamine may cause a lupus-like syndrome or muscle weakness syndrome (myasthenia gravis).

Routine laboratory tests include blood samples of total white blood cell, red blood cell and platelet numbers, plus urinalyses. These generally are obtained every two weeks for the first one to two months then monthly thereafter. Once long-term stable lab results are recorded, the frequency of testing may be decreased.

One of the effects of d-penicillamine is to interact with special areas of proteins called sulfhydryl groups. Other medicines may interfere with this site of the action, particularly a common blood pressure medicine called Capoten® (Captopril), and an arthritis medicine called Plaquenil® (hydroxychloroquine). Neither Capoten nor other drugs of its class, nor Plaquenil should be used while taking d-penicillamine, as they may decrease the beneficial effects of the drug.