Published: 2 March 2023

Publications

Starting empagliflozin or dapagliflozin in patients on lithium? Monitor lithium levels

Published: 2 March 2023
Prescriber Update 44(1): 6–8
March 2023

Medsafe has requested data sheet updates for sodium-glucose co-transporter 2 (SGLT2) inhibitors (empagliflozin and dapagliflozin) and lithium products to include information on the drug-drug interaction between these medicines.

Inhibition of SGLT2 may enhance the renal excretion of lithium

The sodium-glucose co-transporter 2 is responsible for the reabsorption of glucose and sodium in the renal tubules.^1,2

SGLT2 inhibitors are used in the treatment of type 2 diabetes mellitus to improve glycaemic control. They promote glucose excretion by reducing renal absorption of glucose into the blood stream.^1,2

Lithium can substitute for sodium, presumably because it is atomically similar to sodium, and use sodium-transporting systems.³ Therefore, concomitant use of SGLT2 inhibitors and lithium may increase the renal excretion of lithium and lead to decreased serum lithium levels.^1,2,4

Routine monitoring of serum lithium levels is important to ensure they are within therapeutic range

Lithium has a narrow therapeutic index. Routine and regular monitoring is required to ensure appropriate dosing.⁵

Many medicines can influence lithium clearance, by altering renal blood flow, glomerular filtration rate and sodium balance.³

Monitor the patient’s serum lithium levels more frequently when a SGLT2 inhibitor is initiated or following dose changes. Adjust the dose of lithium if necessary.^1,2

New Zealand case reports

Up to 9 January 2023, the Centre for Adverse Reactions Monitoring (CARM) had not received any reports of an interaction between lithium and SGLT2 inhibitors (empagliflozin, dapagliflozin).

More information

Medsafe: Drug interactions with lithium and therapeutic drug monitoring

References

1. AstraZeneca Limited. 2022. Forxiga New Zealand Data Sheet 18 July 2022. URL: medsafe.govt.nz/profs/Datasheet/f/forxigatab.pdf (accessed 12 January 2023).
2. Boehringer Ingelheim (N.Z.) Limited. 2022. Jardiance New Zealand Data Sheet 29 August 2022. URL: medsafe.govt.nz/profs/Datasheet/j/jardiancetab.pdf (accessed 12 January 2023).
3. Shnaider A and Azab AN. 2015. Lithium-induced nephrogenic diabetes insipidus – a case report and discussion on the pathophysiological mechanism. International Journal of Nephrology and Kidney Failure 1(3): 1–4. DOI: 10.16966/2380-5498.113 (accessed 12 January 2023).
4. Armstrong GP. 2020. Empagliflozin-mediated lithium excretion: A case study and clinical applications. The American Journal of Case Reports 21: e923311. DOI: 10.12659/AJCR.923311 (accessed 12 January 2023).
5. New Zealand Formulary (NZF). 2022. NZF v127: Lithium 1 Jan 2023. URL: nzf.org.nz/nzf_2216 (accessed 12 January 2023).