Codeine compound

Codeine (compound 3), which differs from morphine by a single methyl, is used for treating moderate pain, coughs and diarrhea. The in vitro assays on isolated receptors indicate that codeine should be 1,000 times less active than morphine. But when codeine is given orally to patients, it is only five times less active. This difference between in vitro and in vitro is due to a demethylation of codeine in the liver, the removal of the R1 methyl group leading to morphine. 

Nurofen Plus contains 12.8 mg of codeine and 200 mg of ibuprofen per tablet, and is prescribed as 1 -2 tablets every 4-6 h as required. When prescribing codeine compounds, caregivers should calculate total daily exposure to acetaminophen, aspirin and ibuprofen to reduce risks of hepatotoxicity and gastrointestinal bleeding Parenteral the recommended starting dose of codeine is 60 mg every 2 h given as intramuscular or subcutaneous injection. 

Partial synthesis is relatively unimportant in the field of alkaloid synthesis, since only a few compounds are available at low price (see table 23). An exception is the derivatization of the morphine base, which leads to codeine, heroin, and other important compounds. These trivial reactions, however, are covered in elementary text books. 

Narcotic Antitussives. Since its isolation in 1832, codeine [76-57-3] (27) has been one of the most widely used and effective compounds for the treatment of cough. Though less potent than morphine [57-27-2] (28), it has become the reference against which most antitussives are measured. 

Codeine, like morphine, is isolated from the opium poppy. However, the low yield of 0.7—2.5% does not provide sufficient material to meet commercial demands. The majority of marketed codeine is prepared by methylating the phenolic hydroxyl group of morphine. Morphine yields from opium poppy are 4—21%. When prescribed for cough, the usual oral dose is 10—20 mg, three to four times daily. At these doses, adverse side effects are very few. Although the abuse potential for codeine is relatively low, the compound can substitute for morphine in addicts (47). 

Molecular modifications of the morphine skeleton have produced numerous derivatives with antitussive properties, some of which have become commercially significant. Ethyknorphine [76-58-4] (29), a simple homologue of codeine, is prepared by ethylating morphine. It is pharmacologically similar to codeine but is seldom used clinically. Pholcodine [509-67-1] (30), the morpholinoethyl derivative of morphine, is used as an antitussive in a number of European countries. It is about one and a half times as potent as codeine, has Htde or no analgesic activity, and produces minimal physical dependence. The compound is prepared by the amino alkylation of morphine (48). 

Modifications of the morphine skeleton have produced butorphanol [42408-82-2] (35) and drotebanol [3176-03-2] (36), which in animal models have demonstrated antitussive activity much greater than that of codeine (51,52). Butorphanol is also a potent analgetic of the narcotic antagonist type (51). Both compounds possess a unique 14-hydroxyl group. 

Levopropoxyphene [2338-37-6] (42), the optical antipode of the dextrorotatory analgetic propoxyphene, is an antitussive without analgetic activity. The 2-naphthalenesulfonate salt has a less unpleasant taste than the hydrochloride salt, and is widely used. Clinical effectiveness has been demonstrated against pathological and artificially induced cough, but the potency is somewhat less than codeine. The compound is reported not to cause addiction. Levopropoxyphene can be prepared (62) by first resolving [ -dimethylamino-CX-methylpropiophenone with dibenzoyl-(+)-tartaric acid. The resolved... 

Another antitussive with weak antihistaminic activity is the Japanese compound picoperine [21755-66-8] (56). This compound is a stmctural isomer of the weU-known antihistamine tripelennamine and is more potent than codeine. The chemistry (79) and pharmacology (80) of picoperine have been reported. 

Oxolamine [959-14-8] (57) is sold in Europe. It is an oxadiazole, and its general pharmacological profile is described (81). The compound possesses analgesic, antiinflammatory, local anesthetic, and antispasmodic properties, in addition to its antitussive activity. Although a central mechanism may account for some of the activity, peripheral inhibition of the cough reflex may be the dominant effect. The compound has been shown to be clinically effective, although it is less active than codeine (82,83). The synthesis of oxolamine is described (84). 

Dia2epam [439-14-5] (60) and clona2epam [1622-61 -3] (61) suppress cough induced by electrical stimulation of the lower brainstem of cats (90). Clona2epam and dia2epam adrninistered intravenously are about thirty-five times and six times more potent than codeine, respectively. Nevertheless, the compounds have not been widely used as antitussives in humans. Dia2epam is used in the treatment of anxiety, and clona2epam as an anticonvulsant. 

Jsomerides of Morphine and Codeine. When morphine is treated with thionyl chloride, phosphorus trichloride or tribromide, the alcoholic hydroxyl group is replaced by the halogen, forming a-chloromorphide and bromomorphide respectively. The former on treatment with concentrated hydrochloric acid is converted into /3-chloromorphide. Schopf and Hirsch have provided evidence that the two are structural isomerides. With the same reagents codeine yields a parallel set of compounds, viz., a- and -chlorocodides, and bromocodide. The chief characteristics of these products may be summarised thus —... 

This experiment33 illustrates how adjustment of pH may be used to control fluorescence and so make the determination more specific. The alkaloids codeine and morphine can be determined independently because whilst both fluoresce strongly at the same wavelength in dilute sulphuric acid solution, morphine gives a generally negligible fluorescence in dilute sodium hydroxide. The fluorescence intensities of the two compounds are assumed to be additive. 

In addition the role played by the sorbent on which the chromatography is carried out must not be neglected. For instance, it is only on aluminium oxide layers and not on silica gel that it is possible to detect caffeine and codeine by exposure to chlorine gas and treatment with potassium iodide — ben2idine [37]. The detection limits can also depend on the sorbent used. The detection limit is also a function of the h/ f value. The concentration of substance per chromatogram zone is greater when the migration distance is short than it is for components with high h/ f values. Hence, compounds with low h/ f values are more sensitively detected. 

Note Tertiary amines and quaternary ammonium compounds yield stronger colors than primary amines [25]. The dipping solution can also be used as spray solution [44]. Other reagent compositions have also been reported in the literature (1, 3, 6, 12, 13, 15, 18, 21, 23, 41] In some cases the reagents have been made up in acetone [38, 39], methanol [14] or ethanol [37] and/or acidified with hydrochloric acid [3, 33, 37-40]. The concentrations of hexachloroplatinic(IV) acid have been in the range of 0.05 -0.4 those of potassium iodide between 0.5 and 24spray solution containing 2% potassium iodide and 0.23170 hexachloroplatinic(IV) acid hexahydrate in N-hydro-chloric acid is reported to yield the best coloration results with respect to detection sensitivity and color differentiation in the detection of morphine, codeine, quinine, methadone and cocaine [46]. Acidic reagent solutions have been recommended for benzodiazepines [10, 11]. Sulfones do not react [39]. 

Morphine and related opiates are known to suppress the cough reflex these compounds have thus been used extensively in antitussive preparations. Since this activity is not directly related to the analgesic potency, the ideal agent is one that has much reduced analgesic activity and thus, presumably, lower addiction potential. The weak analgesic codeine (4) is... 

Reference compounds. Diazepam Rf 75, chlorprothixene Rf 56, codeine Rf 33, atropine Rf 18. 

Reference compounds. Dipipanone Rf 66, pethidine Rf 37, desipramine Rf 20, codeine Rf 06. 

Alkaloids are compounds that contain nitrogen in a heterocyclic ring and are commonly found in about 15-20% of all vascular plants. Alkaloids are subclassified on the basis of the chemical type of their nitrogen-containing ring. They are formed as secondary metabolites from amino acids and usually present a bitter taste accompanied by toxicity that should help to repel insects and herbivores. Alkaloids are found in seeds, leaves, and roots of plants such as coffee beans, guarana seeds, cocoa beans, mate tea leaves, peppermint leaves, coca leaves, and many other plant sources. The most common alkaloids are caffeine, theophylline, nicotine, codeine, and indole... 

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