Semisynthetic opioid drugs

The term opioid refers to any exogenous substance that acts as an agonist at any of several receptors. Opioid antagonists are drugs that bind to a receptor but produce no actions. The poppy plant, Papaver somniferum, from which opium is obtained, is grown in many areas of the world. Morphine constitutes 10% of opium, and codeine can be obtained direcdy from opium. Semisynthetic opioids such as heroin and oxycodone are obtained directly or indirectly from morphine. There are other distinct chemical classes of drugs with opioid actions, including the methadones. 

Oxycodone is a semisynthetic opioid derived from thebaine and used for oral pain relief. It is commonly formulated as an immediate-re lease medication with acetaminophen or aspirin. A con-trolled-release oxycodone formulation is used for the treatment of moderate to severe pain it provides controlled drug delivery over 12 h. The oral bioavailability of this formulation is 60 to 87%.35 The results of clinical studies of patients with postoperative and cancer pain show that oxycodone has a potency 1.5 times that of morphine. 

Opioids 2-3 days typically Up to 6 days with sustained-release formulations Up to 1 week with prolonged or heavy use Since the assay was made to detect morphine, detection of other opioids, such as codeine, oxycodone, hydrocodone, and other semisynthetic opioids, may be limited. Some synthetic opioids, e.g., fentanyl and meperidine, may not be detected. Drugs such as rifampin and some fluoroquinolones may cause false-positive results depending on the assay. 

The number of Americans abusing prescription drugs doubled from 7.8 million in 1992 to 15.1 million in 2003. The painkiller hydrocodone was used by 7.4% of college students in the United States in 2005. It is a semisynthetic opioid derived from two of naturally occurring opiates, codeine and thebaine. Production of this drug has increased in recent years. In Scandinavia, flunitrazapam, a sedative, is sold as Rohypnol, and it is widely known as a date-rape drug. ... 

Table 8.2 Structure of morphine and some chemically related naturally occurring or semisynthetic clinically important opioid drugs...

Natxirally occurring opiates such as morphine or codeine and semisynthetic opiates such as hydrocodone or hydromorphone have been used as essential pain management components for decades. Since drugs such as these are used chronically in pain treatment and because they possess both euphoric and addictive qualities, they are commonly used illicitly as well. Other drugs, which produce morphine-like effects, are labeled as opioid drugs and are commonly used in similar situations. 

Morphine, when extracted from raw opium and treated chemically, yields the semisynthetic narcotics hydromorphone, oxymorphone, oxycodone, and heroin. Heroin is an illegal narcotic in the United States and is not used in medicine. Synthetic narcotics are those man-made analgesics with properties and actions similar to the natural opioids. Examples of synthetic narcotic analgesics are methadone, levorphanol, remifen-tanil, and meperidine Additional narcotics are listed in the Summary Drug Table Narcotic Analgesics. 

Members of the group of natural, semisynthetic, or synthetic alkaloid compounds prepared from opium are referred to as opioids. This group includes natural compounds usually denoted opiates, such as morphine and codeine, and the synthetic and semi synthetic compounds such as oxycodone, buprenorphine, fentanyl, methadone, and tramadol. The pharmacological effects and pharmacokinetic parameters of these drugs share many common characteristics and are illustrated with the prototypic drug in this class, morphine. 

Semisynthetic and synthetic narcotics are also produced that have opiate-like effects these narcotics are collectively known as opioids. They include methadone and the designer drug fentanyl, and a number of commonly prescribed medicines such as Darvon, Demerol, Dilaudid, Orlaam, OxyContin, Percodan, Talwin, and Vicodin. 

Narcotics (opiates and opioids) are natural, semisynthetic, and synthetic derivatives of the opium poppy. Drugs such as morphine, codeine, heroin, methadone, Darvon, and Percodan fall into this category. They are all depressants, but they are also potent painkillers, and except for heroin (which is illegal) they are prescribed to relieve pain and to control coughing and diarrhea. But because of their pleasurable effects and addictive properties, they can cause problems when taken for nonmedical reasons. Most nonmedical users take these drugs to experience euphoria, to avoid pain, and to relieve withdrawal symptoms. —... 

To date more than 50 pharmaceuticals or drugs of abuse have been reported to be detectable in hair after oral or parenteral administration, in addition to the "classical" drugs mentioned above. The present chapter aims to review the papers devoted to these "unusual" compounds, that have been categorized in 11 classes opioids (i.e., semisynthetic or synthetic morphine derivatives), hallucinogens, psychostimulants (including nicotine), barbiturates, benzodiazepines, other sedatives/hypnotics. 

Among opioids, morphinans (Fig. 1) play an important role as therapeutically valuable drugs. Representative examples of the morphinan class of compounds (Fig. 2) are p-opioid analgesic agents for the treatment of moderate-to-severe pain such as naturally occurring alkaloids (e.g. morphine, codeine), semisynthetic derivatives (e.g. oxycodone, oxymorphone, buprenorphine), and synthetic analogs (e.g. levorphanol, butorphanol) [19-21], Codeine is also an effective antitussive drug. The oxymorphone derivatives naloxone [22] and naltrexone [23] represent... 

Opioid The class of drugs that includes opiates, opiopeptins, and all synthetic and semisynthetic drugs that mimic the actions of the opiates... 

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