A drug may be classified by the chemical type of the active ingredient or by the way it is used to treat a particular condition. Each drug can be classified into one or more drug classes.
When radiopharmaceuticals are used to help diagnose medical problems, only small amounts are given to the patient. The radiopharmaceutical then passes through, or is taken up by, an organ of the body (which organ depends on what radiopharmaceutical is used and how it has been given). Then the radioactivity is detected, and pictures are produced, by special imaging equipment. These pictures allow the nuclear medicine doctor to study how the organ is working and to detect cancer or tumors that may be present in the organ.
Medical conditions associated with diagnostic radiopharmaceuticals: