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Aminoacridine

Mepacrine hydrochloride

Mepacrine hydrochloride (quinacrine) is an antiprotozoal and antiparasitic agent that has been used to treat giardiasis and certain other parasitic infections, and occasionally for some autoimmune conditions in specialist settings.

Dosing — no UK product information found

We found no UK product information (SmPC) for this medicine or presentation on the eMC or MHRA Products (checked October 2026). It may be unlicensed in the UK, imported, a medical device, or no longer marketed. ClinCalc Pro shows only doses it can trace to official product information, so none is shown — follow your specialist service or local guideline.

Clinical monograph

How it works

Its mechanism is not fully established but is thought to involve intercalation into parasite DNA and interference with parasite metabolism; in autoimmune use its antimalarial-type immunomodulatory effects are exploited.

Prescribing in practice

  • High or prolonged exposure has been associated with neuropsychiatric reactions including toxic psychosis, so patients should be monitored and the drug reviewed if such symptoms occur.
  • It commonly causes a reversible yellow discolouration of the skin, urine and sclerae, which should be explained to avoid alarm or confusion with jaundice.
  • Availability is limited and use is largely specialist, so prescribing should follow current prescribing references and expert advice.

Monitoring

Monitor for neuropsychiatric and dermatological effects and review response to treatment during the course.

Counselling the patient

  • This medicine can turn your skin and urine yellow, which is expected and not the same as jaundice.
  • Report any unusual mood changes, agitation or confusion.
  • Take the full course as prescribed.

Evidence & guidelines

Use is based on long-standing pharmacological experience and specialist guidance rather than a single contemporary landmark trial.

Reference: 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.

Pathways