Initial management of acute lithium toxicity includes which step?

• A. Hemodialysis
• B. Hydration with IV fluids
• C. Peritoneal dialysis
• D. Activated charcoal

Answer: (B)

Lithium is cleared by the kidneys, and its excretion is closely tied to kidney perfusion and sodium handling. In acute toxicity, the first priority is to restore intravascular volume and promote renal elimination. Giving intravenous isotonic saline increases circulating volume, enhances glomerular filtration, and delivers more sodium to the proximal tubule, which reduces the reabsorption of lithium and accelerates its clearance. This approach helps prevent ongoing absorption from the gut (if ingestion occurred) from translating into higher serum levels and edema, and it supports overall perfusion.

Activated charcoal is not effective for lithium because lithium is a small element and does not bind well to charcoal. Dialysis (hemodialysis or peritoneal dialysis) becomes necessary only if the patient has severe toxicity—such as very high serum lithium levels, significant neurotoxicity, or renal failure—or if there is failure to improve with aggressive hydration. In those cases, the detoxification step is warranted, but it is not the initial move.

So, the best initial step is hydration with IV fluids to restore volume and enhance renal clearance of lithium.