The most commonly used are the hydrochloride (freebase conversion ratio 0.805, i.e. 10mg of the hydrochloride salt is equivalent in effect to 8.05mg of the freebase form), phosphate (0.736), sulphate (0.859), and citrate (0.842). Others include a salicylate NSAID, codeine salicylate (0.686), a bromide (codeine methylbromide, 0.759), and at least five codeine-based barbiturates, the phenylethylbarbiturate (0.56), cyclohexenylethylbarbiturate (0.559), cyclopentenylallylbarbiturate (0.561), diallylbarbiturate (0.561), and diethylbarbiturate (0.619). The latter was introduced as Codeonal in 1912, indicated for pain with nervousness. Codeine methylbromide is also considered a separate drug for various purposes.Codeine and morphine, as well as opium, were used in an attempt to treat diabetes in the 1880s and thereafter, as recently as the 1950s. Society and culture
Names
It is often sold as a salt in the form of either codeine sulfate or codeine phosphate in the United States, United Kingdom and Australia. Codeine hydrochloride is more common worldwide and the citrate, hydroiodide, hydrobromide, tartrate, and other salts are also seen. The chemical name for codeine is morphinan-6-ol, 7,8-didehydro-4,5-epoxy-3-methoxy-17-methyl-, (5α,6α)-

Recreational use
A heroin (diamorphine) or other opiate/opioid addict may use codeine to ward off the effects of withdrawal during periods where their preferred drug is unavailable or unaffordable.Codeine is also available in conjunction with the anti-nausea medication promethazine in the form of a syrup. Brand named as Phenergan with Codeine or in generic form as promethazine with codeine, it began to be mixed with soft drinks in the 1990s as a recreational drug, called syrup, lean, or purple drank.
Drug withdrawal, drug withdrawal syndrome, or substance withdrawal syndrome, is the group of symptoms that occur upon the abrupt discontinuation or decrease in the intake of pharmaceutical or recreational drugs. In order for the symptoms of withdrawal to occur, one must have first developed a form of drug dependence. This may occur as physical dependence, psychological dependence or both. Drug dependence develops from consuming one or more substances over a period of time. Dependence arises in a dose-dependent manner and produces withdrawal symptoms that vary with the type of drug that is consumed. For example, prolonged use of an antidepressant medication is likely to cause a rather different reaction when discontinued compared to discontinuation of an opioid, such as heroin. Withdrawal symptoms from opiates include anxiety, sweating, vomiting, and diarrhea. Alcohol withdrawal symptoms include irritability, fatigue, shaking, sweating, and nausea. Withdrawal from nicotine can cause irritability, fatigue, insomnia, headache, and difficulty concentrating. Many prescription and legal nonprescription substances can also cause withdrawal symptoms when individuals stop consuming them, even if they were taken as directed by a physician. The route of administration, whether intravenous, intramuscular, oral or otherwise, can also play a role in determining the severity of withdrawal symptoms. There are different stages of withdrawal as well; generally, a person will start to feel bad (crash or come down), progress to feeling worse, hit a plateau, and then the symptoms begin to dissipate. However, withdrawal from certain drugs (barbiturates, benzodiazepines, alcohol, glucocorticoids) can be fatal.