To the editor: In the last 2 years I have seen two patients with the severe pain of ureteral colic. Usually, such patients are given a narcotic, and fluids are forced until the stone, if it is not excessively large, is spontaneously excreted (1). However, the patient may have much pain. It is reasonable to anticipate that a calcium blocker, such as nifedipine, a drug accepted by the Food and Drug Administration that dilates spastic coronary arteries, (2) might have a similar effect on spastic ureters, which have a histologic structure like that of the arteries—an internal epithelial cell lining,