1. Opiates
Option D, Section 3

2. Morphine Naturally occurring in the poppy - only needs to be isolated
Belong to group of alkaloids
Very strong pain reliever but also very addictive (2nd to heroin)
Usually injected but can be smoked, sniffed, or swallowed
Commonly used in hospitals
Large illegal street culture

3. Strong Analgesics Morphine and its derivatives (opiates)
Known as narcotic analgesics
Used to relieve severe pain associated with injuries, heart attacks, or chronic diseases such as cancer
Most strong analgesics are derived from the opium poppy or synthetically produced

4. Mechanism of Strong Analgesics
The human body contains “natural opiates” in the brain called endorphins
These are produced in the body during extreme conditions such as “running high” and extreme injuries.
When these are absorbed by receptors in the brain the body feels analgesia and the pain is reduced.

5. Mechanism of Strong Analgesics
Opiates derived from the poppy act in the same way as endorphins but are not natural to the human body.
The “high” is produced because of the absorption of opiates is quicker than endorphins
Drugs such as naloxone act to fill the receptors in the brain but are not analgesics and thus are used to prevent overdoses on analgesics.
Endorphins are not used as analgesics because they cannot be stored and are unstable.

6. Mechanism of Strong Analgesics
Temporarily bind to opioid receptors in the brain to depress the central nervous system (CNS)

7. Side Effects of Strong Analgesics
Short term
Dulling of Pain
Euphoria
Slow Nervous system
Slowed heart rate
Loss of cough reflex
Nausea
Overdoses can lead to death
Possibility of stroke
Overall slowdown of biological systems
Long Term
Addiction and very strong withdrawal effects
Constipation
Loss of libido
Disruptions in menstruation
“Cross-tolerance”
Loss of appetite
Problems associated with buying street drugs i.e. sharing needles AIDS and prostitution.

8. Crossing the blood-brain barrier
Activity of opiates depends on ability to cross blood-brain barrier – a series of lipophilic cell membranes that cover the blood vessels and prevent polar molecules from entering the CNS.
Lipophilic – dissolves in fats (lipids)
Presence of one amino and two hydroxyl groups makes it polar enough to be soluble, but reduces the ability to reach the opioid receptors in the brain.

9. Codeine Derivative of morphine
Modify one phenolic group to ether group
Can cross the blood brain barrier, but does not bind to opioid receptor because of steric hindrance of ether group.
Metabolized into morphine which can bind opioid receptor.
10x less potent than morphine
Commonly used with Tylenol as a more mild analgesic
Low activity, wide therapeutic window, and limited potential for abuse makes it the most widely used opiate in the world.
Steric hindrance: stopping of a reaction because of shape of molecule (wrong or too bulky to fit receptor).

10. Heroin (diamorphine)
Derivative of morphine – both hydroxyl groups substituted with ester groups.
Prepared from reacting morphine with ethanoic anhydride (?)
Soluble in lipids (crosses blood-brain barrier) and is quickly metabolized into morphine.
5 times more potent than morphine, but has more severe side effects
Most dangerous substances of abuse. Responsible for nearly 50% of all drug-related deaths around the world. Banned or restricted to terminally ill patients with certain forms of cancer or CNS disorders.

11. Heroin (diamorphine)
Originally sold as cough suppressant and a pain killer

12. Methadone Compared to most strong analgesics it is weaker.
Has been synthesized to not have euphoric properties and mild withdrawal effects but is still addictive.
Used as an analgesic but most commonly to help in the withdrawal for heroin addicts.

13. Other Synthetic Strong Analgesics
Vicodin
Is solution of acetaminophen and hydrocodone (the latter being the stronger)
Hydrocodone is addictive and can cause highs.
Usually taken orally
Stronger than codeine but not as strong than Morphine

14. Demerol Demerol (Meperidine)
Used for moderate to severe pain and to stop muscle spasms.
Usually injected or taken orally.