Tramadol 
Tramadol hydrochloride (Ultram, Tramal others below) is a centrally acting opioid analgesic, used in treating moderate to severe pain. The drug has a wide range of applications, including treatment for restless leg syndrome and fibromyalgia. It was developed by the pharmaceutical company Grunenthal GmbH in the late 1970s.
Tramadol possesses weak agonist actions at the ?-opioid receptor, releases serotonin, and inhibits the reuptake of norepinephrine.
Tramadol is a synthetic analog of the phenanthrene alkaloid codeine and, as such, is an opioid and also a prodrug (codeine is metabolized to morphine, tramadol is converted to O-desmethyltramadol). Opioids are chemical compounds which act upon one or more of the human opiate receptors. The euphoria and respiratory depression are mainly caused by the ?1 and ?2 receptors; the addictive nature of the drug is due to these effects as well as its serotonergic/noradrenergic effects. The opioid agonistic effect of tramadol and its major metabolite(s) are almost exclusively mediated by the substance's action at the ?-opioid receptor. This characteristic distinguishes tramadol from many other substances (including morphine) of the opioid drug class, which generally do not possess tramadol's degree of subtype selectivity.
Medical uses Tramadol is used similarly to codeine, to treat moderate to moderately severe pain. Tramadol is somewhat pharmacologically similar to levorphanol (albeit with much lower ?-agonism), as both opioids are also NMDA-antagonists which also have SNRI activity (other such opioids to do the same are dextropropoxyphene (Darvon) & M1-like molecule tapentadol (Nucynta, a new synthetic atypical opioid made to mimic the agonistic properties of tramadol's metabolite, M1(O-Desmethyltramadol). Tramadol is also molecularly similar to venlafaxine (Effexor) and has similar SNRI effects, with antinociceptive effects also observed. It has been suggested that tramadol could be effective for alleviating symptoms of depression, anxiety, and phobias[6] because of its action on the noradrenergic and serotonergic systems, such as its "atypical" opioid activity. However, health professionals have not endorsed its use for these disorders, claiming it may be used as a unique treatment (only when other treatments failed), and must be used under the control of a psychiatrist.
In May 2009, the United States Food and Drug Administration issued a Warning Letter to Johnson & Johnson, alleging that a promotional website commissioned by the manufacturer had "overstated the efficacy" of the drug, and "minimized the serious risks". The company which produced it, the German pharmaceutical company Grunenthal GmbH, were the ones alleged to be guilty of "minimizing" the addictive nature and proposed efficacy of the drug, although it showed little abuse liability in preliminary tests. The 2010 Physicians Desk Reference contains several warnings from the manufacturer, which were not present in prior years. The warnings include more compelling language regarding the addictive potential of tramadol, the possibility of difficulty breathing while on the medication, a new list of more serious side effects, and a notice that tramadol is not to be used in place of opiate medications for addicts. Tramadol is also not to be used in efforts to wean addict patients from opiate drugs, nor to be used to manage long-term opiate addiction.
Adverse effects Main side effects of tramadol. Red color denotes more serious effects, requiring immediate contact with health provider.
The most commonly reported adverse drug reactions are nausea, vomiting, sweating, itching and constipation. Drowsiness is reported, although it is less of an issue than for non-synthetic opioids. Patients prescribed tramadol for general pain relief with or without other agents have reported withdrawal symptoms including uncontrollable nervous tremors, muscle contracture, and 'thrashing' in bed (similar to restless leg syndrome) if weaning off the medication happens too quickly. Anxiety, 'buzzing', 'electrical shock' and other sensations may also be present, similar to those noted in Effexor withdrawal. Respiratory depression, a common side-effect of most opioids, is not clinically significant in normal doses. By itself, it can decrease the seizure threshold. When combined with SSRIs, tricyclic antidepressants, or in patients with epilepsy, the seizure threshold is further decreased. Seizures have been reported in humans receiving excessive single oral doses (700 mg) or large intravenous doses (300 mg). However, there have been several rare cases of people having grand-mal seizures at doses as low as 100–400 mg orally. An Australian study found that of 97 confirmed new-onset seizures, eight were associated with tramadol, and that in the authors' First Seizure Clinic, "tramadol is the most frequently suspected cause of provoked seizures". There appears to be growing evidence that Tramadol use may have serious risks in some individuals and it is contra-indicated in patients with uncontrolled epilepsy (BNF 59). Seizures caused by tramadol are most often tonic-clonic seizures, more commonly known in the past as grand mal seizures. Also when taken with SSRIs, there is an increased risk of serotonin toxicity, which can be fatal. Fewer than 1% of users have a presumed incident seizure claim after their first tramadol prescription. Risk of seizure claim increases 2- to 6-fold among users adjusted for selected comorbidities and concomitant drugs. Risk of seizure is highest among those aged 25–54 years, those with more than four tramadol prescriptions, and those with a history of alcohol abuse, stroke, or head injury. Dosages of warfarin may need to be reduced for anticoagulated patients to avoid bleeding complications. Constipation can be severe especially in the elderly requiring manual evacuation of the bowel.[citation needed] Furthermore, there are suggestions that chronic opioid administration may induce a state of immune tolerance,[30] although tramadol, in contrast to typical opioids may enhance immune function. Some have also stressed the negative effects of opioids on cognitive functioning and personality.
Chemistry
Characteristics Structurally, tramadol closely resembles a stripped down version of codeine. Both codeine and tramadol share the 3-methyl ether group, and both compounds are metabolized along the same hepatic pathway and mechanism to the stronger opioid, phenol agonist analogs. For codeine, this is morphine, and for tramadol, it is the O-desmethyltramadol.
Comparison with related substances
Structurally, tapentadol is the closest chemical relative of tramadol in clinical use. Tapentadol is also an opioid, but unlike both tramadol and venlafaxine, tapentadol represents only one stereoisomer and is the weaker of the two, in terms of opioid effect. Both tramadol and venlafaxine are racemic mixtures. Structurally, tapentadol also differs from tramadol in being a phenol, and not an ether. Also, both tramadol and venlafaxine incorporate a cyclohexyl moiety, attached directly to the aromatic, while tapentadol lacks this feature. In reality, the closest structural chemical entity to tapentadol in clinical use is the over-the-counter drug phenylephrine. Both share a meta phenol, attached to a straight chain hydrocarbon. In both cases, the hydrocarbon terminates in an amine.
[edit] Synthesis and stereoisomerism
(1R,2R)-Tramadol (1S,2S)-Tramadol
(1R,2R)-Tramadol (1S,2S)-Tramadol
(1R,2S)-Tramadol (1S,2R)-Tramadol
(1R,2S)-Tramadol (1S,2R)-Tramadol The chemical synthesis of tramadol is described in the literature.[36] Tramadol [2-(dimethylaminomethyl)-1-(3-methoxyphenyl)cyclohexanol] has two stereogenic centers at the cyclohexane ring. Thus, 2-(dimethylaminomethyl)-1-(3-methoxyphenyl)cyclohexanol may exist in four different configurational forms:
(1R,2R)-isomer
(1S,2S)-isomer
(1R,2S)-isomer
(1S,2R)-isomer The synthetic pathway leads to the racemate (1:1 mixture) of (1R,2R)-isomer and the (1S,2S)-isomer as the main products. Minor amounts of the racemic mixture of the (1R,2S)-isomer and the (1S,2R)-isomer are formed as well. The isolation of the (1R,2R)-isomer and the (1S,2S)-isomer from the diastereomeric minor racemate [(1R,2S)-isomer and (1S,2R)-isomer] is realized by the recrystallization of the hydrochlorides. The drug tramadol is a racemate of the hydrochlorides of the (1R,2R)-(+)- and the (1S,2S)-(–)-enantiomers. The resolution of the racemate [(1R,2R)-(+)-isomer / (1S,2S)-(–)-isomer] was described[37] employing (R)-(–)- or (S)-(+)-mandelic acid. This process does not find industrial application, since tramadol is used as a racemate, despite known different physiological effects [38] of the (1R,2R)- and (1S,2S)-isomers, because the racemate showed higher analgesic activity than either enantiomer in animals[39] and in humans.[40]
kfskfgsgdsfdfsdffd
