MEDICINES [home] [topic page]
The opiates have produced a variety of very powerful medicines.
Generally the opiates are used as analgesics - pain killing drugs, as they mimic the actions of the enkephaloids in their behaviour, tying to the same receptors in the brain. Unfortunately, the greater pain relief, generally the higher the addiction liability.
Thebaine is a convulsant producing no analgesia. It has no direct medical benefits and is very dangerous in the raw state.
Morphine has, since its discovery in 1809, been used to increase tolerance to pain. It is still one of the main drugs used for the relief of extreme pain. Like most opioids, it also produces a feeling of euphoria but has other side effects like constipation and respiratory depression.
Codeine, by the replacement of the -OH with -OCH3 on the benzene ring reduces the activity to 15% of morphine. ( The bigger the replacement group at this position, the larger the reduction.) Codeine is used in cough medicines as an "antitussive" - literally an anticough agent.
( On the other hand, changing the -OH group to -OCH3 on the cyclohexene ring actually increases the activity to give heterocodeine.)
Oxycodone - The new thebaine production has coincided with the increased use of oxycodone as a substitute for morphine in the USA. It is a very strong pain reliever and is used typically with terminally ill patients.
The similarity of oxycodone to thebaine is quite apparent and the conversion is reasonably simple.
Buprenorphine is a very powerful analgesic that has gained some popularity in medicine and can be derived from both thebaine and oripavine.
Many additional drugs are created directly or indirectly from the natural opioids.
Naltrexone is used to treat former heroin addicts
. .
Naloxone is an antagonist used to block the effects of heroin overdose.
Notice the same basic structures as morphine but with additional chains off the nitrogen and other modifications.
Two terms are common in discussing the interaction of opiates and human chemistry.
What is addiction? Addiction to morphine, heroin and such comes about when the body adapts to these drugs. These replace the standard, natural enkephaloids in the brain, taking over their function and suppressing the enkephaloid production. The body is then deeply ill if supply of the addictive drug is not maintained as inadequate enkephalins are available to maintain the brain's health.
Further reference