STUDIES ON THE ABSORPTION, EXCRETION AND METABOLISM OF DIMETHYLSULFOXIDE (DMSO) IN MAN

¹ Merck Sharp & Dohme Research Laboratories, West Point, Pennsylvania

The absorption, excretion and metabolism of dimethylsulfoxide (DMSO) have been studied in man by gas chromatography and radiometric techniques. The drug was readily absorbed when administered dermally, peak serum levels occurring after 4 to 8 hr. Orally administered drug was rapidly absorbed, reaching a peak in serum in 4 hr. Serum levels of DMSO were undetectable after 120 hr. Both unchanged drug and a metabolite, dimethylsulfone (DMSO₂), were isolated from urine. DMSO₂ appeared in serum after about 48 hr and persisted in serum for as long as 400 hr. Urinary excretion of DMSO after dermal and oral administration amounted to approximately 13% and 30 to 68% of the dose, respectively. Excretion of DMSO₂ was about 5 to 10% and 21 to 23%, respectively. Data for subjects given DMSO chronically are also presented, as is evidence that the fraction of DMSO excreted is entirely accounted for by unchanged drug and DMSO₂.