Opiate-Based Medicines

There are many legal medicines that use opiates or opiate-like substances. Most of the opiate-based medicines used today are not made from natural opiates, but are either synthetic or semi-synthetic. Synthetic opiate drugs are not actually opiates at all they are merely different chemicals that act like opiates. Semi-synthetics are those drugs that involve changing the chemical structure of a natural opiate. An example of this is heroin, which is a human-made variation of morphine. Morphine and codeine are the principal natural opiates used as medicines and what follows are descriptions of the other most frequently used opiate-based medicines. 

Codeine is a natural alkaloid found in the opium plant. As a pharmaceutical, codeine is used as an analgesic, antitussive, and antidiar-rheal. Codeine is also commonly combined with other cough suppressants as well as with aspirin and ibuprofen. In the United States, codeine is a Schedule III controlled substance, which means that its distribution is more tightly regulated than unscheduled drugs. Codeine has pain-relieving qualities principally because, once in the body, about 10 percent of codeine turns into morphine. This conversion occurs in the liver, where an enzyme changes codeine s 

Related to codeine, dihydrocodeine is a rather weak analgesic, usually combined with other drugs and used as a headache suppressant, ft is often, however, prescribed for postoperative pain, dyspnea, and as an antitussive. Dihydrocodeine is twice as potent as codeine. 

Fentanyl is a semi-synthetic opioid, ft is a much more powerful version of morphine. Fentanyl is used during surgery as an anesthetic and is extremely dangerous when taken in a nonmedical context. First created in Belgium in the 1950s, fentanyl is 80 times more powerful than morphine. Due to its strength, fentanyl is listed as a Schedule I narcotic in the United States. 

Even though this very powerful pharmaceutical is extremely dangerous, it has been used illicitly at least since the mid-1970s. 

---

Modern Opiate-Based Medicines 75 Table 8.1 Common Pharmaceuticals Containing Opiates... 

In addition to the medicines mentioned above, a number of opiate- and non-opiate-based analgesics, including COX-2 inhibitors, anaesthetics (e.g. propofol, desflurane, sevoflurane, ropivacaine, levobupivacaine and remifentanil), neuromuscular blockers (e.g. rocuronium bromid, zemuron, cisatracuiium, doxacurium. 

Phyto chemicals can be used to either stimulate or inhibit motility of the GIT. For example, caffeine and other phytochemicals stimulate motility (Lis-Balchim etal, 2001 Boekema et al, 1999), whereas motility is slowed by peppermint oil (Beesley et al, 1996), protease inhibitors (Schwartz et al., 1994) and several other phytochemicals (Abdullahi et al, 2001 Odetola and Acojenu, 2000 Rojas et al, 1999 Amos et al, 1998). Many of the traditional herbal medicines used for treatment of diarrhea are based on aqueous extracts that slow small intestine transit and increase residence time for digesta (Lin et al, 2002). The opiates and derivatives are particularly noteworthy (Williams et al., 1997). 

Naloxone hydrochloride hydrate (Narcan, l-A-allyl-7,8-dihydro-14-hydroxynormorphinone hydrochloride) [51481-60-8] M 399.9, m 200-205°, [aJo -164° (c 2.5, H2O). This opiate antagonist has been recrystd from EtOH + Et2O. or H2O. It is soluble in H2O (5%) and EtOH but insoluble in Et2O. The free base has m 184° (177-178°) after recrystn from EtOAc, [a] -194.5° (c 0.93, CHCI3). [Olofson et al. TET LETT 1567 1977 Gold et al. Medicinal Research Reviews 2 211 7982]. 

We are now going to look in detail at one of the oldest fields in medicinal chemistry, yet one where true success has proved illusive—the search for a safe, orally active, and non-addictive analgesic based on the opiate structure. 

---