| Warfarin Reversal Agent | Not Available | 1 | 5 | Details |
| Water Pollutants | Substances or organisms which pollute the water or bodies of water. Use for water pollu... more | 1 | 3 | Details |
| Water Pollutants, Chemical | Liquid produced when water percolates through landfill waste. | 2 | 4 | Details |
| Watersoluble, Hepatotropic X-Ray Contrast Media | Not Available | 9 | 4 | Details |
| Watersoluble, Nephrotropic, High Osmolar X-Ray Contrast Media | Not Available | 10 | 1 | Details |
| Watersoluble, Nephrotropic, Low Osmolar X-Ray Contrast Media | Not Available | 12 | 0 | Details |
| Waxes | A plastic substance deposited by insects or obtained from plants. Waxes are esters of v... more | 1 | 0 | Details |
| Whey | The liquid components of milk that remain after the CASEIN, fat, and fat soluble compon... more | 0 | 0 | Details |
| Whey Proteins | The protein components of milk obtained from the whey. | 3 | 0 | Details |
| Wolman Disease, drug therapy | Not Available | 1 | 0 | Details |
| Wound Healing | Not Available | 4 | 6 | Details |
| X-Ray Contrast Activity | Not Available | 14 | 1 | Details |
| X-Ray Contrast Media, Iodinated | Not Available | 35 | 5 | Details |
| X-Ray Contrast Media, Non-Iodinated | Not Available | 1 | 0 | Details |
| Xanthenes | Compounds with three aromatic rings in linear arrangement with an OXYGEN in the center ... more | 22 | 63 | Details |
| Xanthine derivatives | A methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial ... more | 43 | 141 | Details |
| Xanthine Oxidase Inhibitors | An xanthine oxidase inhibitor is any substance that inhibits the activity of xanthine o... more | 3 | 18 | Details |
| Xanthines and Adrenergics | Not Available | 6 | 44 | Details |
| Xanthones | A group of XANTHENES that contain a 9-keto OXYGEN. | 1 | 4 | Details |
| Xanthophylls | Oxygenated forms of carotenoids. They are usually derived from alpha and beta carotene. | 3 | 1 | Details |
| Xanthurenates | Cyclic compounds that include atoms other than carbon in their ring structure. | 2 | 3 | Details |
| Xenon Isotopes | Stable xenon atoms that have the same atomic number as the element xenon, but differ in... more | 3 | 0 | Details |
| Yellow Fever Vaccines | Not Available | 1 | 0 | Details |
| Yttrium | An element of the rare earth family of metals. It has the atomic symbol Y, atomic numbe... more | 1 | 0 | Details |
| Yttrium (90Y) Compounds | Not Available | 1 | 0 | Details |