Extract Thiabendazole (MK 360) (Merck) is a new anthelmintic about which there has been no literature published as yet† †Paper received for publication 29 August, 1961. View all notes, but unpublished information supplied by the manufacturers showed it to be a very promising addition to the existing series. It is rapidly absorbed and readily excreted, and therefore does not accumulate in the body. The compound is non-staining and has a wide safety margin. It may be administered in the form of a drench, bolus or capsule.