Morphine

Morphine is a narcotic pain reliever. It belongs to the opiate family of drugs and contains the principal alkaloid in opium and the prototype opiate analgesic and narcotic. Morphine suppresses the couch reflex and some side effects are constipation and nausea. Morphine attaches to three specific receptors (mu, delta, and kappa)in the brain and act as an antagonist. Morphine reduces the chances of ion channels to open on these receptors. Meaning, very roughly, less channels open; less neurotransmitters received; less pain and other sensations like that produced; a sense of euphoria is instilled. Another thing morphine does is it debilitates the amount of GABA released. GABA is what is used to suppress the releasing of dopamine. So, if GABA is inhibited, more dopamine is released and more pleasure (along with mood swings and dependence on morphine) is elicited.

If morphine is used for a long time it inhibits the activation of cAMP. But cAMP production is picks up by other mechanisms and if morphine is then dropped (no longer used) there becomes an over production of cAMP which leads to hyperactivity and an intense craving of the drug.

The constipation and nausea side effects are caused by morphine acting on the myenteric plexus and the submucous plexus in the digestive tract. Morphine slows, if in high enough doses stops, the plexus’s functions which causes the constipation because the food is not being broken down or moved along the tract.

If this drug is misused, how to counteract the effects of this drug involves; the use of other drugs to fight off the digestive malfunction side effects, and slowly take less and less of the opiate to make the withdrawals less severe and less frequent. Another effect of morphine is mood swings. If enough morphine is taken mood swing can parallel with those of bipolar and even borderline individuals and it may be necessary to take psychotropic drugs to counteract the mood swings.

http://www.drugs.com/morphine.html

http://wiki.answers.com/Q/What_does_morphine_do_to_you

http://thebrain.mcgill.ca/flash/i/i_03/i_03_m/i_03_m_par/i_03_m_par_heroine.html

http://www.homehealth-uk.com/medical/morphine.htm