Codeine and its metabolites are excreted almost entirely by the kidney, mainly as conjugates with glucuronic acid.The active metabolites of codeine, notably morphine, exert their effects by binding to and activating the μ-opioid receptor. Chemistry
Relation to other opioids
Codeine has been used in the past as the starting material and prototype of a large class of mainly mild to moderately strong opioids; such as hydrocodone (1920 in Germany), oxycodone (1916 in Germany), dihydrocodeine (1908 in Germany), and its derivatives such as nicocodeine (1956 in Austria). However, these opioids are no longer synthesized from codeine and are usually synthesized from other opium alkaloids; specifically thebaine. Other series of codeine derivatives include isocodeine and its derivatives, which were developed in Germany starting around 1920. In general, the various classes of morphine derivatives such as ketones, semisynthetics like dihydromorphine, halogeno-morphides, esters, ethers, and others have codeine, dihydrocodeine, and isocodeine analogues. The codeine ester acetylcodeine is a common active impurity in street heroin as some codeine tends to dissolve with the morphine when it is extracted from opium in underground heroin and morphine base labs. As an analgesic, codeine compares weakly to other opiates. Related to codeine in other ways are codoxime, thebacon, codeine-N-oxide (genocodeine), related to the nitrogen morphine derivatives as is codeine methobromide, and heterocodeine, which is a drug six times stronger than morphine and 72 times stronger than codeine due to a small re-arrangement of the molecule, namely moving the methyl group from the 3 to the 6 position on the morphine carbon skeleton.
A tuberculoma is a clinical manifestation of tuberculosis which conglomerates tubercles into a firm lump, and so can mimic cancer tumors of many types in medical imaging studies. Since these are evolutions of primary complex, the tuberculomas may contain within caseum or calcifications. With the passage of time Mycobacterium tuberculosis can transform into crystals of calcium. These can affect any organ such as the brain, intestine, ovaries, breast, lungs, esophagus, liver, pancreas, bones, and many others. As the histologic and clinical indications, as well as tumor markers such as the CA-125, are similar, it is often difficult to differentiate tuberculoma from cancer. For these reasons, tuberculosis should always be considered in the differential diagnosis of cancer.Tuberculoma is commonly treated through the HRZE drug combination (Isoniazid, Rifampin, Pyrazinamide, Ethambutol) followed by maintenance therapy. == References ==