Comparative Pharmacology
Head-to-head clinical analysis: FENTANYL 100 versus FENTANYL CITRATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FENTANYL 100 versus FENTANYL CITRATE.
FENTANYL-100 vs FENTANYL CITRATE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Fentanyl is a μ-opioid receptor agonist. It binds to μ-opioid receptors in the central nervous system, activating G-protein coupled receptor signaling (inhibition of adenylate cyclase, modulation of ion channels), leading to increased potassium conductance and decreased calcium influx, resulting in hyperpolarization and reduced neurotransmitter release. This produces analgesia, sedation, and respiratory depression.
Fentanyl is a potent synthetic opioid agonist that primarily acts on mu-opioid receptors in the central nervous system, leading to analgesia, sedation, and euphoria. It also interacts with kappa and delta opioid receptors to a lesser extent. By binding to these receptors, fentanyl inhibits adenylate cyclase, reduces cAMP production, closes voltage-gated calcium channels, and opens inwardly rectifying potassium channels, resulting in hyperpolarization and reduced neurotransmitter release.
100 mcg intravenously every 1-2 hours as needed for pain; or 100 mcg intramuscularly every 1-2 hours; transdermal patch: 12-100 mcg/hour applied every 72 hours; buccal tablet: 100-200 mcg as a single dose for breakthrough pain.
Initial adult dose 50-100 mcg IV/IM every 1-2 hours as needed for pain; for anesthesia induction 2-20 mcg/kg IV.
None Documented
None Documented
Terminal elimination half-life: 2–4 hours in adults; prolonged in elderly, hepatic impairment, or continuous infusion (due to redistribution).
Terminal elimination half-life: 3-12 hours (mean 4-6 hours in adults). Context: Prolonged with hepatic impairment, elderly, or continuous infusion (context-sensitive half-life increases with infusion duration).
Primarily hepatic metabolism to inactive metabolites (norfentanyl, etc.); ~75% excreted in urine as metabolites, ~9% in feces, <10% unchanged in urine.
Primarily hepatic metabolism (N-dealkylation to norfentanyl and other metabolites); less than 10% excreted unchanged in urine; approximately 9% excreted in feces via biliary elimination.
Category D/X
Category D/X
Opioid Agonist
Opioid Agonist