Lithium toxicity following a change from semaglutide to tirzepatide for weight loss management

Clinicians should be vigilant when initiating or switching GLP-1-modulating agents in patients receiving lithium. Pharmacokinetic studies are needed to clarify the mechanism of this interaction. Until more is known, increased monitoring of lithium levels is warranted, with initiation of a GLP-1-modulating agent, a dose change, or switching to another agent.