Codeine chemical properties

Together, the chemistry of codeine and the drug s absorption into the bloodstream, distribution to various compartments and tissues in the body, metabolism (breakdown of the parent compound into smaller molecules, or metabolites), and excretion are intimately related to how codeine exerts its medicinal or therapeutic effects. Codeine s chemical properties and pharmacologic characteristics explain how, figuratively speaking, a spoonful of codeine can relieve pain, suppress cough, or act as an antidiarrheal. 

Many pharmacologically active organic chemicals fonnd in natnre are alkaloids. In general, these componnds contain one or more nitrogen atoms, which in turn impart some basicity to the molecnle. Well-known alkaloid examples are caffeine, cocaine, codeine, ephedrine, morphine, nicotine, qninine, and scopolamine. Heroin is derived from morphine by a chemical modification that increases lipophilicity, making the heroin molecnle inherently more pharmacologically potent than morphine. The exhibition of its basic properties by an alkaloid (Aik) involves (by definition) the acceptance of a proton H+ according to ... 

Codeine is a close chemical relative of morphine, differing in only one chemical group. Once administered, codeine is actually metabolized by enzymatic action, and its actions mimic those of morphine. Codeine is used primarily as a cough suppressant, although it certainly also possesses significant analgesic properties (approximately one tenth those of morphine) as in the relief of pain from toothache. 

The family of the Papaveraceae includes 31 genera and approximately 700 species (2). The alkaloids contained therein are derivatives of the 1-benzyltetrahydroisoquinoline alkaloid reticuline (1). For the classification and chemical data of the described alkaloids (3-5) as well as for the pharmacodynamic properties of morphine and codeine (6, 7) see reviews. Some pharmacological aspects have been dealt with by Shamma (5) and Krueger et al. (8). 

Alkaloids are widespread in plants and include some very well-known poisons (notably coniine and strychnine), hallucinogens (morphine, cocaine and muscimol) and other potentially lethal compounds that are nevertheless used in medical practice (e.g. atropine, codeine, colchicine and morphine). As indicated by the preliminary snap-shot above, alkaloids typically have names ending in -ine and which are often related to the plant source or properties. Thus, morphine was named after Morpheus (the God of sleep) and coniine derives from Conium maculatum (hemlock), the plant used in the judicial murder of Socrates (399 BC). Various chemical tests for alkaloids are used as preliminary indicators of alkaloid presence in crude plant extracts. Finally, it should be noted that alkaloids can also exist as jVoxides of the alkaloid base. 

In contrast to 14-hydroxydihydrocodeine-B the C-isomer is converted by phosphorus pentachloride to substances containing phosphorus. The difference in behaviour of the two isomers is similar to that of the epimeric pair dihydrocodeine and dihydroisocodeine, and there is nothing about the chemical or pharmacological properties of the two isomers incompatible with the view that 14-hydroxydihydrocodeine-B has the codeine and the C-isomer the isocodeine arrangement of groups at C-6 [6]. 

Determine the acid-base character of the functional groups in the two molecules drawn above as well as the salt form of codeine phosphate. As originally drawn above, which of these two agents is more water soluble Provide a rationale for your selection that includes appropriate structural properties. Is the salt form of codeine phosphate more or less water soluble than the free base form of the drug Provide a rationale for your answer based on the structural properties of the salt form of codeine phosphate. What is the chemical consequence of mixing aqueous solutions of each drug in the same IV bag Provide a rationale that includes an acid-base assessment. 

Dextromethorphan, a simplified codeine, is a much-prescribed cough suppressant, with neither analgesic nor addictive properties. Chemically, it is ( + )-3-methoxy-iV-methylmorphinan. Ijts laevo stereoisomer has the analgesic and euphoric properties of morphine and (although not used in medicine) stands at the end of a line of work initiated by Grewe (1947) who was the first to show that the morphinan series can produce strong analgesics. 

In relation to their chemical structure and action, they can be classified into two categories. The first are phenanthrene alkaloids and are under international control morphine (MO), codeine (COD), and thebaine (TB), which act on the central nervous system and are used as analgesics, narcotics, and potentially addicting compounds (pain relievers). Heroin is synthesized from MO. The second group is isoquinoline alkaloids Papaverine (PV) and narcotine (also known as noscapine). Narcotine acts only to relax involuntary smooth muscles, for which it is considered an antitussive, and lacks addictive, analgesic, respiratory, narcotic, depressant, and sedative properties. Next to MO, which constitute about 10% by weight of raw opium, is the second most abundant alkaloid present in opium. The three last alkaloids (PV, narcotine, and narceine) are not under international control specially, narcotine and narceine which have scarcely any medical or other uses. Consequently, the five economically significant alkaloids of opium are MO, COD, TB, PV, and narcotine. 

---