zinc acetate dihydrate: clinical use

Prescribing considerations

• Initiate and supervise treatment through a clinician experienced in Wilson’s disease.
• Because onset is slow, zinc acetate dihydrate is not recommended as sole initial treatment for symptomatic disease.
• Watch for early clinical deterioration and use particular caution when changing a stable patient with portal hypertension from chelation to zinc.
• Assess food, supplement and antimicrobial use for absorption interactions.

Contraindications and cautions

• Hypersensitivity to zinc acetate dihydrate or any product excipient.

Monitoring

• Monitor clinical hepatic, neurological and psychiatric status.
• Use plasma and urinary copper assessments to detect inadequate control or overtreatment.
• Urinary or plasma zinc may help assess adherence.
• Monitor full blood count for anaemia or leukopenia and lipoproteins for biochemical evidence of copper deficiency.
• Assess new sensory or motor symptoms for possible copper-deficiency myeloneuropathy.
• Use especially close monitoring in children and during pregnancy.

Clinical pharmacology

The zinc cation induces enterocyte metallothionein, which sequesters dietary and endogenously secreted copper and limits transfer into the circulation. Its therapeutic effect is primarily local to the intestine.

Formulation and product differences

• The selected product is an aqua-blue hard capsule containing gelatin, titanium dioxide and brilliant blue FCF.
• The capsule may be opened and its contents suspended in a little water for a child who cannot swallow it.
• Food substantially delays zinc absorption; protein appears to interfere less than fibre-, phytate- or dairy-containing foods.

Capsule

Route: Oral

Strengths: 25 mg, 50 mg