Opioids

(or natural opioids), are morphine and morphine derivatives and are all aromatic

fentanyl and fentanyl-like compounds

• Phenanthrene • Synthetic All interact (bind) with the opioid receptors, predominantly mu opioid receptors, but other opioid receptors exist. Most are agonists, but some are antagonists

Note the presence of the phenyl and piperidine rings. Note the similarity of each compound except for the lipophilic side group.

• Fentanyl is 100x more potent than morphine. • Sufentanil is approx 1000x more potent than morphine. • Alfentanil less potent than fentanyl. • All are more lipid soluble than morphine.

Remifentanil is short-acting due to its rapid metabolism by ester hydrolysis and to a lesser degree by N-dealkylation.

SUBLIMAZE (fentanyl citrate) injection is a potent narcotic analgesic. Each milliliter of solution contains fentanyl citrate equivalent to 50 mcgm of fentanyl base, adjusted to pH 4.0-7.5 with sodium hydroxide.