penicillamin

Penicillamine is a sulfhydryl-containing amino acid derivative used as a chelating agent in medicine. It is the D-enantiomer of penicillamine and has no antibiotic activity. The drug is primarily employed to promote the excretion of certain metals and to modify copper handling in the body.

The most important clinical use of penicillamine is in the treatment of Wilson’s disease, a genetic disorder of copper metabolism. By binding copper, penicillamine forms soluble complexes that are eliminated in the urine, helping to reduce copper accumulation in tissues. It has also been used as a chelating agent for other heavy metals, including lead and mercury, though its role in these cases has diminished with the availability of other chelators. Historically, penicillamine was prescribed as a disease-modifying antirheumatic drug for rheumatoid arthritis, but its use for this indication has declined due to toxicity and the availability of better-tolerated therapies.

Mechanistically, penicillamine acts through its sulfhydryl group to form stable complexes with metals, enhancing their renal excretion. In Wilson’s disease, this leads to lowered body copper burden. There is also evidence that penicillamine can exert immunomodulatory effects, which partly explains its past use in autoimmune conditions, though the exact mechanisms in RA are not fully understood.

Administration and safety considerations: penicillamine is given orally, with careful monitoring. Dosing and duration depend on the indication and patient tolerance. Regular monitoring includes blood counts, urinalysis, liver and kidney function, and assessment for hypersensitivity or nephrotoxic effects. Adverse effects can include skin reactions, proteinuria, hematologic abnormalities, and rare drug-induced lupus–like syndrome. Contraindications include significant renal impairment and known hypersensitivity.