Delayed recrudescence to toxic salicylate concentrations after salsalate overdose

Salicylates are common exposures. We report an unusual case of salicylate ingestion, as salsalate, with resolution of symptoms and return of salicylate levels to non-toxic values, with a subsequent, unexpected recrudescence to toxic levels requiring reinstitution of therapy. A 31-year-old man ingested unknown amounts of salsalate, hydroxyzine, and a benzodiazepine. He was intubated and treated with IV sodium bicarbonate and two doses of oral activated charcoal. Eight hours after presentation, his serum salicylate concentration peaked at 55 mg/dL, and then decreased to a nadir of 5.6 mg/dL 38 h after presentation, coinciding with return of GI motility. Several hours later salicylate concentrations began to rise, peaking 67 h after presentation at 61.7 mg/dL. He was treated with sodium bicarbonate and charcoal, which resulted in decreased serum salicylate to therapeutic levels. Salicylate ingestions are known to exhibit unusual toxicokinetics and absorption in overdose; however, this is the first case we are aware of that shows a return to toxic concentrations after apparent resolution of toxicity. Recrudescence of salicylate concentrations to a degree that would dictate reinstitution of therapy for overdose is unusual and may warrant prolonged monitoring of serum salicylate concentrations in salsalate ingestions.