Visammin (khellin) is a crystalline derivative of the Middle-Eastern plant Ammi visnaga lam; it was identified as a dimethoxy-methyl-furano chromone 1 and was synthesized in 1949. 2 Samaan's 3 pharmacologic studies in the early 1930's indicated that the drug relaxed isolated muscle preparations from the bronchus of the pig and dog by a direct effect on the muscle fibers. Barsoum and associates 4 reported that absorption of visammin from the stomach and small bowel was rapid, with a maximum blood concentration reached within 30 to 60 minutes after oral administration. When the drug was given intramuscularly, there was a rapid increase in the concentration of it in the circulating blood within 15 to 20 minutes; it soon became stabilized at a level similar to that reached after oral administration of the same dose. The destruction and excretion of visammin proceeded slowly, so that repeated doses had a cumulative effect. Since