A

Lithium’s elimination half-life is roughly 24 h, and even therapeutic concentrations potentiate neuromuscular blockade and can cause peri-operative hypotension. Peri-operative guidelines therefore advise withholding the drug the day before surgery—i.e., stop 24 h (1 day) prior to anaesthesia—to allow serum levels to fall and minimize drug–anaesthetic interactions [Kaufman, 1985, PMID 3926008; Meijer, 2005, PMID 16136738].