The concentrations of inorganic fluoride and nonvolatile organic fluoride were measured in a patient with nephrotoxic effects following methoxyflurane anesthesia. Concentrations of both were markedly elevated compared to two patients who received methoxyflurane without subsequent nephrotoxic effects. Indirect evidence suggests that the inorganic fluoride concentration was sufficient to account for the nephrotoxic effects. The prolonged elevation of inorganic fluoride observed can be explained on the basis of the breakdown of the nonvolatile organic fluoride to inorganic fluoride and the poor renal clearance of both types.
Taves DR, Fry BW, Freeman RB, Gillies AJ. Toxicity Following Methoxyflurane AnesthesiaII. Fluoride Concentrations in Nephrotoxicity. JAMA. 1970;214(1):91-95. doi:10.1001/jama.1970.03180010033006