penicillamine

Absorption: Well absorbed after oral administration.

Distribution: Crosses the placenta.

Metabolism/Excretion: Some excreted in urine as heavy metal–penicillamine complex, some excreted in urine as cystine-penicillamine complex, some metabolized by the liver.

Half-Life: 1–7.5 hr (4–6 days during long-term use).

Time/Action Profile ⬆ ⬇

ROUTE	ONSET	PEAK	DURATION
PO (antirheumatic)	2–3 mo	unknown	1–3 mo
PO (Wilson’s disease)	1–3 mo	unknown	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Cross-sensitivity with penicillin may exist;
Patients currently receiving gold salts, antimalarials, or antineoplastics;
Concurrent use of iron supplements;
OB: Should be avoided in pregnant women with rheumatoid arthritis or cystinuria;
Lactation: Lactation.

Use Cautiously in:

Renal impairment (↑ risk of adverse renal reactions in patients with rheumatoid arthritis);
History of aplastic anemia due to penicillamine;
Patients requiring surgery (may impair wound healing);
OB: For pregnant women with Wilson’s disease, limit daily dose to <1 g. If Cesarean section is planned, ↓ daily dose to 250 mg for last 6 wk of pregnancy and until incision is healed;
Geri: ↑risk of hematologic toxicity, skin rash and taste abnormality in older adults; dose ↓ recommended).

Adv. Reactions/Side Effects ⬆ ⬇

Derm: pemphigus, ecchymoses, hives, itching, rash, wrinkling

EENT: blurred vision, eye pain

GI: altered taste, anorexia, cholestatic jaundice, diarrhea, dyspepsia, epigastric pain, hepatic impairment, nausea, oral ulceration, PANCREATITIS, vomiting

GU: proteinuria

Hemat: leukopenia, anemia, APLASTIC ANEMIA, eosinophilia, thrombocytopenia, thrombocytosis

MS: arthralgia, migratory polyarthritis

Neuro: myasthenia gravis syndrome

Resp: coughing, shortness of breath, wheezing

Misc: allergic reactions, GOODPASTURE’S SYNDROME (GLOMERULONEPHRITIS AND INTRA-ALVEOLAR HEMORRHAGE), fever, lymphadenopathy, systemic lupus erythematosus–like syndrome

Interactions ⬆ ⬇

Drug-drug:

↑risk of adverse hematologic effects with antineoplastics, immunosuppressants, or gold salts; avoid concurrent use.
Concurrent administration of iron supplements↓ absorption of penicillamine.
May ↓ serum digoxin levels.

Drug-Food:

May ↑ requirements for pyridoxine (vitamin B₆).

Route/Dosage ⬆ ⬇

PO (Adults ): Antirheumatic: 125–250 mg/day as a single dose; may be slowly ↑ up to 1.5 g/day.Chelating agent (Wilson’s disease): 250 mg 4 times daily. Antiurolithic: 500 mg 4 times daily.
PO (Children >6 mo): Chelating agent (Wilson’s disease): 250 mg/day as a single dose; older children may receive the adult dose. Antiurolithic: 7.5 mg/kg 4 times daily.

Availability ⬆ ⬇

(Generic available)

Capsules: 250 mg
Tablets: 250 mg

Assessment ⬆ ⬇

Monitor intake and output and daily weight, and assess for edema during therapy. Notify health care professional if edema or weight gain occurs.
- Monitor patient for allergic reactions (rash, fever). Discontinue treatment and reinstitute at lower dose (250 mg/day), increasing gradually. Prednisone 20 mg/day may be administered for the first few wk of therapy to decrease severity of reactions. Antihistamines may be used to control pruritus.
Arthritis: Assess pain and range of motion periodically during therapy.
Cystinuria: Monitor X-ray examinations for renal calculi annually for stone formation.

Lab Test Considerations:

Monitor CBC with differential, platelet counts, and urinalysis (especially for protein and cells) at least every 2 wk during the first 6 mo of therapy or after dose ↑ and monthly thereafter. May cause leukopenia, anemia, and thrombocytopenia. Discontinue therapy if WBC <3500/mm³, neutrophils <2000/mm³, monocytes <500/mm³, platelet count <100,000/mm³, or if hematuria occurs.
- Monitor liver function tests every 6 mo during first 18 mo of therapy.
- May cause a positive ANA test result.
- May cause hypoglycemia.
- Arthritis: Monitor 24-hr urinary protein levels every 1–2 wk in patients with moderate proteinuria.
- Wilson’s disease: Monitor urinary copper levels before and soon after initiation of therapy and every 3 mo during continued therapy.
- Cystinuria: Monitor urinary cystine levels. Urinary cystine excretion should be maintained at <100 mg in patients with a history of pain or calculi or at 100–200 mg in patients without a history of calculi.

Implementation ⬆ ⬇

Do not confuse penicillamine with penicillin.
PO: Administer on an empty stomach, at least 1 hr before or 2 hr after meals. Other medications should be administered at least 1 hr apart from penicillamine to maximize absorption.
- Do not administer concurrently with products containing iron.
- Penicillamine increases the daily requirements for pyridoxine. Supplemental doses of pyridoxine 25 mg/day (vitamin B) may be required in patients with impaired nutrition.
Arthritis: Dose adjustments may be required every 2–3 mo during therapy.
- If no improvement is seen after 3–4 mo of therapy with doses of 1–1.5 g daily, medication should be discontinued.
Wilson’s Disease: Sulfurated potash (10–40 mg) may be administered with meals to minimize copper absorption.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take penicillamine as directed. If on once-daily schedule, take missed doses as soon as remembered unless remembered the next day; if on twice-daily schedule, take missed doses as soon as remembered unless almost time for next dose; if on more than twice-daily dosing schedule, take missed doses within 1 hr or omit. Do not double doses.
- Consult health care professional before discontinuation of therapy, as interruption of therapy may cause sensitivity reactions when therapy is resumed. Therapy should be resumed starting with smaller dose and increasing gradually.
- Inform patient that penicillamine may alter taste acuity, which may be restored by administration of copper 5–10 mg daily. Cupric sulfate 4% solution 5–10 drops may be mixed in fruit juice and taken twice daily. This is contraindicated in patients with Wilson’s disease.
- Advise patient to notify health care professional of medication regimen before surgery or treatment. Dose of penicillamine should be reduced until wound healing is complete.
- Instruct patient to notify health care professional of skin rash, unusual bleeding or bruising, sore throat, exertional dyspnea, unexplained coughing or wheezing, fever, chills, or any unusual effects.
- May be teratogenic. Advise females or reproductive potential to use effective contraception during therapy and to notify health care professional if pregnancy is planned or suspected or if breastfeeding. If penicillamine is administered during pregnancy to patients with Wilson's disease, recommended daily dose be limited to 750 mg. If cesarean section is planned, reduce daily dose to 250 mg, but not lower, for last 6 wk of pregnancy and postoperatively until wound healing is complete.
- Emphasize the importance of follow-up exams to check progress.
Wilson’s Disease: Advise patient to discuss dietary restrictions with health care professional. A low-copper diet may be required. Chocolate, nuts, shellfish, mushrooms, liver, molasses, broccoli, and cereals enriched with copper should be avoided. If drinking water contains >100 mcg/liter of copper, distilled or demineralized water should be used.
Cystinuria: Advise patient to maintain a fluid intake of at least 2000–3000 mL/day, with increased fluids at night.
- Advise patient to discuss dietary restrictions with health care professional. Low-methionine diet may be required to minimize cystine production but is contraindicated in growing children or pregnancy because of low protein content.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇