Prodrug not its intended target. This reduces adverse or unintended effects of a drug, especially important in treatments like chemotherapy, which can have severe unintended and undesirable side effects. Many herbal extracts historically used in medicine contain glycosides (sugar derivatives) of the active agent, which are hydrolyzed in the intestines to release the active and more bioavailable aglycone. For example, salicin is a β-D-glucopyranoside that is cleaved by esterases to release salicylic acid. Aspirin, acetylsalicylic acid, first made by Felix Hoffmann at Bayer in 1897, is a synthetic prodrug of salicylic acid. However, in other cases, such as codeine and morphine,
Technetium (99mTc) medronic acid Technetium (99mTc) medronic acid Technetium (Tc) medronic acid (MDP) is a pharmaceutical product used in nuclear medicine to localize bone metastases as well as other diseases that can alter the natural turn-over in the bone by bone scintigraphy. The drug is a complex of medronic acid, the simplest bisphosphonate, with technetium-99m (Tc), a radionuclide that emits gamma rays. The exact structure of the complex is not known. Tc-MDP must be prepared in a radiopharmacy. It is usually supplied as a "cold kit" to which radioactive Tc from a generator is added. Kit composition may vary between suppliers, but contents typically