Chelating antidote (heavy metals) / antirheumatic agent
Penicillamine is an oral chelator used in Wilson disease (copper overload), cystinuria (cystine stones) and severe active rheumatoid arthritis unresponsive to conventional therapy. It binds metals (copper, iron, zinc) and cystine, promoting their elimination. It is a closely monitored drug: it requires regular monitoring (blood count, urine, renal function) and must never be used in pregnancy, except in very specific cases.
Also known as: Penicilamina, Cuprimine
Penicillamine + antacids: antacids reduce penicillamine absorption — separate administration.
The FDA penicillamine label is explicit: "Food, antacids, and iron reduce absorption of the drug", and the Prontuário Terapêutico records "Antacids (reduce absorption)". The divalent and trivalent cations of antacids (aluminium, magnesium) form chelates with penicillamine in the GI tract, reducing the oral bioavailability of the chelator — an effect with direct consequences for the efficacy of treatment of heavy metal poisoning, Wilson disease and rheumatoid arthritis. The practical guidance is to separate administration: give penicillamine on an empty stomach (1 hour before or 2 hours after meals) and keep antacids at least 2 hours apart. In Wilson disease patients where cupruria control is the efficacy marker, simultaneous intake may lead to false lack of response.
Penicillamine + antacids: antacid cations chelate penicillamine and reduce its absorption — separate administration by at least 2 hours.
The FDA penicillamine label documents: "Food, antacids, and iron reduce absorption of the drug", and the Prontuário records "Antacids (reduce absorption)". The cations (aluminium, magnesium) of antacids chelate penicillamine in the GI tract, reducing its bioavailability and the efficacy of treatment (heavy metal poisoning, Wilson disease, rheumatoid arthritis).
Assessment of clinical response to treatment (e.g., cupruria in Wilson disease) during the combination.
Lack of therapeutic response or recurrence of symptoms when taking antacids together.
Give penicillamine on an empty stomach, 1 hour before or 2 hours after meals, and separate from antacids by at least 2 hours.
DailyMed/FDA (NIH/NLM) — approved Penicillamine label (CUPRIMINE): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=80e736d3-2017-4d68-94b4-38255c3c59c6 ; approved Antacids label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0a13ac81-0c63-48c1-bbb0-f6e67f97b896 ; Prontuário Terapêutico do INFARMED (11th ed., 2012) — Penicillamine, 17
Penicillamine + iron: iron reduces penicillamine absorption — separate administration.
The FDA label documents that iron reduces penicillamine absorption ("Food, antacids, and iron reduce absorption of the drug") and the Prontuário Terapêutico records "Ferrous sulphate (reduces its serum concentrations)". Iron forms chelates with penicillamine in the GI tract, reducing the chelator bioavailability and, conversely, prolonged penicillamine treatment may worsen iron deficiency (urinary metal losses and absorption interference). The interaction is relevant in chelation patients who also need iron supplementation — common in Wilson disease with associated anaemia and in chronic poisonings. The practical guidance is to separate administration by at least 2 hours and give penicillamine on an empty stomach, monitoring clinical response to treatment.
Penicillamine + iron: iron chelates penicillamine and reduces its absorption — separate administration by at least 2 hours.
The FDA label documents that iron reduces penicillamine absorption ("Food, antacids, and iron reduce absorption of the drug") and the Prontuário records "Ferrous sulphate (reduces its serum concentrations)". Iron chelates penicillamine in the GI tract; the combination may reduce the chelator efficacy and, conversely, penicillamine may worsen iron deficiency.
Monitor clinical response and blood count (iron) during the combination.
Lack of response to chelating treatment or worsening of iron-deficiency anaemia.
Separate penicillamine and iron by at least 2 hours; give penicillamine on an empty stomach.
DailyMed/FDA (NIH/NLM) — approved Penicillamine label (CUPRIMINE): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=80e736d3-2017-4d68-94b4-38255c3c59c6 ; approved Iron label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=73d1f079-d8eb-44f4-b33d-05fb25b80c8f ; Prontuário Terapêutico do INFARMED (11th ed., 2012) — Penicillamine, 17
Penicillamine + zinc: zinc reduces penicillamine absorption — separate administration.
The FDA penicillamine label includes zinc among the agents that reduce drug absorption (the wording "antacid, zinc, or iron-containing preparation" explicitly confirms zinc). Zinc chelates penicillamine in the GI tract, reducing oral bioavailability — an effect of particular clinical significance in Wilson disease, where zinc is itself used as maintenance therapy (induces metallothionein and blocks intestinal copper absorption) and penicillamine as first-line chelator: simultaneous intake compromises both mechanisms. The practical guidance is to separate doses by at least 2 hours and monitor response to chelating treatment (cupruria, neurological symptoms).
Penicillamine + zinc: zinc chelates penicillamine and reduces its absorption — separate administration by at least 2 hours.
The FDA label documents zinc among the agents that reduce penicillamine absorption (the formulation "antacid, zinc, or iron-containing preparation" confirms zinc). Zinc chelates penicillamine in the GI tract, reducing bioavailability; relevant in Wilson disease (where zinc is also used as therapy) and in supplementation.
Monitor clinical response to chelating treatment during the combination.
Lack of response to treatment or interference with Wilson disease therapy.
Separate penicillamine and zinc-containing preparations by at least 2 hours.
DailyMed/FDA (NIH/NLM) — approved Penicillamine label (CUPRIMINE): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=80e736d3-2017-4d68-94b4-38255c3c59c6 ; approved Zinc label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c527d138-e32c-418f-9573-a3d8a796279f
The FDA label documents: "Food, antacids, and iron reduce absorption of the drug" — taking with food reduces penicillamine absorption (40–70% without food, with inter-individual variation).
Give penicillamine on an empty stomach, 1 hour before or 2 hours after meals, and separate from antacids and iron by at least 2 hours.
DailyMed/FDA (NIH/NLM) — approved Penicillamine label (CUPRIMINE): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=80e736d3-2017-4d68-94b4-38255c3c59c6
Teratogenic — "Penicillamine can cause fetal harm when administered to a pregnant woman... teratogenic in rats... Skeletal defects, cleft palates, and fetal toxicity (resorptions) have been reported" and congenital cutis laxa in infants of treated mothers. Exception: selected Wilson disease or cystinuria ("Except for the treatment of Wilson's disease or certain patients with cystinuria, use of penicillamine during pregnancy is contraindicated").
Contraindicated in pregnancy, except selected Wilson disease/cystinuria; inform the patient of the risk, request immediate reporting of missed menses and follow closely for early pregnancy recognition.
DailyMed/FDA (NIH/NLM) — approved Penicillamine label (CUPRIMINE): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=80e736d3-2017-4d68-94b4-38255c3c59c6
The label: "Because of its potential for causing renal damage, penicillamine should not be administered to rheumatoid arthritis patients with a history or other evidence of renal insufficiency" — risk of additional renal injury and impaired excretion of the drug and chelated complexes.
Do not give to rheumatoid arthritis patients with renal insufficiency (history or evidence); assess renal function before and periodically during treatment.
DailyMed/FDA (NIH/NLM) — approved Penicillamine label (CUPRIMINE): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=80e736d3-2017-4d68-94b4-38255c3c59c6
The label: "Patients with a history of penicillamine-related aplastic anemia or agranulocytosis should not be restarted on penicillamine" — restarting after penicillamine-related aplastic anaemia or agranulocytosis is contraindicated due to the risk of fatal recurrence.
Do not restart penicillamine after an episode of related aplastic anaemia or agranulocytosis; monitor blood count regularly during treatment.
DailyMed/FDA (NIH/NLM) — approved Penicillamine label (CUPRIMINE): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=80e736d3-2017-4d68-94b4-38255c3c59c6
Teratogenic — "Penicillamine can cause fetal harm when administered to a pregnant woman" (label): teratogenic in rats (doses 6× the highest recommended human dose), skeletal defects, cleft palates, fetal toxicity (resorptions) and congenital cutis laxa with associated birth defects in infants of treated mothers. Exception: selected Wilson disease or cystinuria (label).
Contraindicated in pregnancy, except selected Wilson disease/cystinuria; in women of childbearing potential use only when the expected benefit outweighs the possible hazards.
Mothers on penicillamine therapy should not nurse their infants ("mothers on therapy with penicillamine should not nurse their infants").
In women of childbearing potential: inform of the risk, advise immediate reporting of missed menses and consider pregnancy testing; follow closely for early recognition.
DailyMed/FDA (NIH/NLM) — approved Penicillamine label (CUPRIMINE): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=80e736d3-2017-4d68-94b4-38255c3c59c6
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Oral chelator that forms soluble complexes with heavy metals (copper, lead, mercury) and with cystine, increasing their urinary excretion; in rheumatoid arthritis it has an immunomodulatory effect (reduction of acute-phase reactants) of not fully clarified mechanism.
Chelator ("3-mercapto-D-valine") whose thiol group binds divalent and trivalent metals (copper in Wilson disease, lead/mercury in poisonings) and cystine (forming the more soluble penicillamine-cysteine disulfide), promoting renal excretion. In rheumatoid arthritis it modulates the immune response, reducing disease activity.
Rapid but incomplete absorption (40–70%) from the GI tract ("absorbed rapidly but incompletely (40-70%) from the gastrointestinal tract"), with wide inter-individual variation. Peak plasma concentration occurs 1 to 3 hours after ingestion (~1–2 mg/L after an oral 250 mg dose). Food, antacids and iron reduce absorption.
A small fraction of the dose is metabolised in the liver to S-methyl-D-penicillamine ("A small fraction of the dose is metabolized in the liver to S-methyl-D-penicillamine"); excretion is mainly renal, chiefly as disulfides. After stopping prolonged treatment there is a slow elimination phase lasting 4 to 6 days.
More than 80% of plasma penicillamine is bound to proteins ("More than 80% of plasma penicillamine is bound to proteins, especially albumin and ceruloplasmin"); it also binds erythrocytes and macrophages. There is no single plasma half-life — elimination is biphasic, with a slow terminal phase of 4 to 6 days.
