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Conventional DMARD — Chelating Agent

Penicillamine

Brand names: Distamine

Penicillamine is a chelating agent and disease-modifying drug used in rheumatoid arthritis, Wilson's disease (copper overload) and cystinuria.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION In all patients receiving penicillamine, it is important that penicillamine capsules be given on an empty stomach, at least one hour before meals or two hours after meals, and at least one hour apart from any other drug, food, or milk. Because penicillamine increases the requirement for pyridoxine, patients may require a daily supplement of pyridoxine (see PRECAUTIONS ). W i l s on 's Disease — Optimal dosage can be determined by measurement of urinary copper excretion and the determination of free copper in the serum. The urine must be collected in copper-free glassware, and should be quantitatively analyzed for copper before and soon after initiation of therapy …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-09-24. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

It chelates metal ions such as copper, promoting their urinary excretion in Wilson's disease, and reduces cystine concentrations in cystinuria. Its immunomodulatory action in rheumatoid arthritis is not fully understood but reduces disease activity over time.

Prescribing in practice

  • It can cause serious toxicity, including proteinuria and nephrotic syndrome and bone-marrow suppression (such as thrombocytopenia and neutropenia), requiring regular urine testing and full blood counts as set out in the SPC.
  • Autoimmune syndromes (for example a lupus-like illness, myasthenia gravis or skin disorders) can develop during treatment.
  • It should be taken on an empty stomach, well separated from food, iron, antacids and other mineral-containing products, which reduce its absorption.

Monitoring

Perform regular full blood counts and urinalysis for proteinuria and haematuria, with renal function checks, in line with current prescribing references. Be alert for emerging autoimmune features and for skin or mucosal reactions, and adjust or stop treatment promptly if significant toxicity develops.

Counselling the patient

  • Take this medicine on an empty stomach, at least an hour before or two hours after food, and well apart from iron tablets, antacids and milk.
  • Attend for your regular blood and urine tests, as they pick up serious side effects early.
  • Report a sore throat, fever, unusual bruising or bleeding, or a skin rash promptly.

Evidence & guidelines

A long-established disease-modifying and chelating agent; UK practice emphasises strict haematological and urinary monitoring because of its toxicity profile.

Reference: MHRA Drug Safety Update; BSR/BHPR DMARD Guidelines; SPC Distamine; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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