D.3 - Opiates Flashcards
What ability does a drug that crosses the blood-brain barrier depend on?
The chemical structure and solubility in water and lipids.
What are opiates?
They are natural narcotic analgesics (pain relief) which are derived from the opium poppy.
What are some examples of strong analgesics?
Morphine and codeine.
How do strong analgesics work?
They temporarily bond to receptor sites in the brain, preventing the transmission of pain impulses without depressing the central nervous system.
What are the medical use and addictive properties of opiate compounds related to?
The presence of opioid receptors in the brain.
What are the advantages and disadvantages of strong analgesics?
Advantages: relieve severe pain caused by injury e.g. heart attacks, cancer. There is also a faster distribution of the drug because it is administered intravenously.
Disadvantages: side-effects (feel euphoria, lack of self-control, indulge in dangerous behaviour), dependency and addiction (this is why they are only available when given a prescription), increased risks associated with intravenous drug administration.
How is diamorphine produced?
From morphine in an esterification reaction in which both OH groups are converted into ester (ethanoate) groups.
How is codeine produced?
From morphine in a methylation reaction. This is where and OH group is converted into a method (OCH3) group.
