Morphine is a narcotic analgesic. Morphine is the principal alkaloid obtained from the unripened seed capsules of the opium poppy, Papaver somniferum. It was first isolated in 1803 and is the prototype of the opiate agonists. Today, the poppy is still the source of the drug because synthesis of Morphine is difficult. Morphine is available for administration as the hydrochloride or sulfate salt in all dosage forms. It sulfate is a strong analgesic used primarily for the relief of severe pain. Higher doses are useful for preoperative sedation and as a supplement to anesthesia. Morphine is also used for analgesia during labor. The effect on uterine contractions depends on the stage of labor when Morphine is administered. Morphine is the drug of choice for pain associated with myocardial infarction. it, as well as other opioids, can produce euphoria, feelings of well being, and tranquility, subjecting them to abuse. All opioid drugs can cause physical dependence, so their use is restricted. Morphine is a schedule C-II controlled substance and was in use for many years prior to its approval by the newly-formed FDA in 1939. Another dosage form, MorphiDex, is nearing the end of phase III investigation as of May 1997. It stimulates µ, ? receptors with little or no activity on sigma and delta receptors. Clinically, stimulation of µ and ? receptors produces analgesia, euphoria, respiratory depression, miosis, decreased gastrointestinal motility, and physical dependence.