Phenanthrene
- Natural opioids
- Morphine and morphine derivatives
- Came from poppyseed plant
Synthetic Opioids
- Fentanyl and fentanyl-like compounds (made in the lab)
2. Greater potency than phenanthrene
Both phenanthrene and synthetic opioids bind to opioid receptors, predominant what type?
- Mu opioid receptors, but other opioid receptors exist
2. Most are agonists, but there are few antagonists (overdose)
Phenanthrene Opioid structures
All had 3 ring structure- all aromatic
- Morphine, strong opioid agonist- has hydroxyl groups in the rings, pyridine rings sharing carbons
- Codeine, opioid agonist (weaker than morphine) demethylates to form active metabolite
- Naloxone, opioid antagonist, binds to receptor to impede drugs from activating the site
Piperidine Opioid Structure
All have the presence of phenyl and piperidine rings.
All have saturated six membered ring that is puckered- not flat aromatic ring
1. Fentanyl- 100X more potent than morphine
2. Sufentanil is approximately 1000X more potent than morphine
3. All 3 are more lipid soluble than morphine*
4. Piperidine opioids are formulated as citrate salts
Carfentil
- In the new lately as a party drug
2. Has an extra phenyl group
Remifentanil and metabolism
- Short acting due to its rapid metabolism by ester hydrolysis and to a less degree by N-dealkylation
- Has ester group
- ester group is more unstable drug and needs to be in a acidic solution. Basic solutions will cause hydrolysis to happen quickly
Chemical description of fentanyl
- Sublimate (fentanyl citrate) injection is a potent narcotic analgesic
- Each ml of soltuions contains fentanyl citation equivalent to 50 mcg of fentanyl base, adjusted to ph 4.0-7.0 with sodium hydroxide
- For every molecule of fentanyl you have a citrate to counter act it
- Citrate form (means basic ionized form)
- Piperidine opioids are formulated as citrate salts*
Meperidine
Note similarity to fentanyl including direct attachment of phenyl group to piperidine ring
-Called “phenylpiperidine”
