Published: 5 March 2020

Publications

Interacting elements – zinc-induced copper deficiency

Prescriber Update 41(1): 16-17
March 2020

Zinc may inhibit the absorption of copper, leading to reduced copper levels and potentially copper deficiency¹. This deficiency is due to an interaction between zinc and copper, where zinc inhibits the intestinal absorption of copper².

Copper is an essential trace element and deficiency may result in anaemia, leucopenia, neutropenia and thrombocytopenia³. Early diagnosis is important to avoid the possibility of developing disabling and frequently irreversible neurological symptoms⁴.

In New Zealand, Zincaps capsules are indicated for use in adults as a zinc supplement. The Zincaps data sheet was recently updated to include the zinc and copper interaction. The data sheet also has information about other medicines that interact with zinc.

The risk of copper deficiency may be greater with long-term treatment (eg, if zinc deficiency is no longer present) and/or with higher doses of zinc¹.

When treating copper-deficient patients, concomitant zinc should be administered with caution.

References

1. Pharmacy Retailing (NZ) Ltd trading as Healthcare Logistics. 2020. Zincaps New Zealand Data Sheet 10 January 2020. URL: medsafe.govt.nz/profs/Datasheet/z/Zincapscap.pdf (accessed 18 February 2020).
2. Wapnir RA and Balkman C. 1991. Inhibition of copper absorption by zinc. Biological Trace Element Research 29(3): 193–202. DOI: 10.1007/bf03032677 (accessed 13 January 2020).
3. Gabreyes AA, Abbasi HN, Forbes KP, et al. 2013. Hypocupremia associated cytopenia and myelopathy: A national retrospective review. European Journal of Haematology 90(1): 1–9. DOI: 10.1111/ejh.12020 (accessed 10 February 2020).
4. Duncan A, Yacoubian C, Watson N, et al. 2015. The risk of copper deficiency in patients prescribed zinc supplements. Journal of Clinical Pathology 68(9): 723–5. DOI: 10.1136/jclinpath-2014-202837 (accessed 10 February 2020).