THERAPEUTICS

Brands

• Cuprimine, Depen

Generic?

• Yes

Class

• Chelating agent

Commonly Prescribed for

(FDA approved in bold)

• Wilson's disease (WD)

• Cystinuria

• Rheumatoid arthritis (severe, active)

• Lead poisoning

How the Drug Works

• In WD, copper accumulates in body tissues, causing neurological/psychiatric problems and/or liver failure. Penicillamine is cysteine, doubly substituted with methyl groups. Penicillamine binds to (chelates) copper, allowing it to be excreted in the urine

How Long Until It Works

• Urinary excretion of copper will increase in less than 24 hours. Clinical improvement usually takes 6 months or more; many patients may experience paradoxical worsening after starting treatment

If It Works

• Continue treatment, if tolerated, and aim for 24-hour urine copper excretion of 2mg. Most patients remain on drug for the rest of their life but if all results return to normal (serum copper < 10mcg/dL), consider changing to zinc. Monitor for recurrence of symptoms or changes in urinary copper excretion

If It Doesn't Work

• Increase to as much as 2g daily. Intolerance is more common than ineffectiveness. Change to trientine, and for liver failure or truly refractory patients, liver transplantation is curative

Best Augmenting Combos for Partial Response or Treatment-Resistance

• Change to trientine if ineffective or poorly tolerated. A diet low in copper-containing foods, such as nuts, chocolate, liver, and dried fruit, is recommended

Tests

• Patients with WD have low serum ceruloplasmin and serum copper, but increased urinary excretion of copper is diagnostic. In pediatric patients, a 24-hour urinary copper excretion more than 1600mcg after 500mg dose of penicillamine is considered diagnostic of WD. While on treatment, check CBC and urinalysis, and monitor for skin changes and fever twice weekly for 1 month, then every 2 weeks for the next 5 months, and monthly for the remainder of treatment

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• Unknown

Notable AEs

• Fever, pruritus, changes in taste perception, tinnitus, optic neuritis, neuropathies, abdominal pain, anorexia, pancreatitis, proteinuria/hematuria, oral ulcerations, alopecia