SUFENTANIL CITRATE
Clinical safety rating: avoid
Positive evidence of fetus risks but benefits may outweigh risks in some cases
Selective mu-opioid receptor agonist; inhibits ascending pain pathways and alters pain perception and emotional response to pain.
| Metabolism | Primarily hepatic via N-dealkylation and O-demethylation mediated by CYP3A4; metabolites are mostly inactive; undergoes extensive first-pass metabolism. |
| Excretion | Renal (metabolites, <1% unchanged); fecal (biliary elimination of metabolites); approximately 80% renal, 20% fecal. |
| Half-life | Terminal elimination half-life: 2-4 hours (adults), 1-3 hours (neonates), 3-6 hours (elderly). Context: context-sensitive half-time increases with infusion duration. |
| Protein binding | Approximately 92.5% bound; primarily to alpha-1-acid glycoprotein and albumin. |
| Volume of Distribution | Steady-state Vd: 1.5-3.0 L/kg; large Vd indicates extensive tissue distribution. |
| Bioavailability | Intravenous: 100%; epidural: approximately 90%; intrathecal: approximately 100% (relative to IV); oral: negligible due to first-pass metabolism. |
| Onset of Action | Intravenous: 1-3 minutes; epidural: 5-10 minutes; intrathecal: 5-15 minutes. |
| Duration of Action | Intravenous: 20-30 minutes (analgesic effect, dose-dependent); epidural: 1-4 hours (dose-dependent); context: redistribution limits duration, higher doses prolong effect. |
| Molecular Weight | 386.55 g/mol (for sufentanil base; citrate salt ~578.6 g/mol) |
0.5-5 mcg/kg IV/IM for induction of anesthesia; 0.1-0.3 mcg/kg IV for epidural analgesia; 0.3-0.8 mcg/kg IV for short operative procedures; maintenance with 0.1-0.3 mcg/kg IV every 1-2 hours as needed.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for mild to moderate impairment (eGFR ≥30 mL/min/1.73m²). For severe impairment (eGFR <30 mL/min/1.73m²), consider reducing dose and titrating cautiously due to potential accumulation of metabolites. |
| Liver impairment | For Child-Pugh Class B: reduce dose by 25-50%. For Child-Pugh Class C: avoid use or reduce dose by 50% with careful monitoring. |
| Pediatric use | Neonates: 0.5-1 mcg/kg IV for minor procedures; Children 1-12 years: 0.5-2 mcg/kg IV for induction; maintenance 0.1-0.3 mcg/kg IV every 1-2 hours. Titrate based on response. |
| Geriatric use | Reduce initial dose by 50% (e.g., 0.25-2.5 mcg/kg IV) and titrate slowly due to increased sensitivity and prolonged half-life. Consider lower infusion rates. |
| 1st trimester | Sufentanil citrate is not recommended for use in the first trimester due to potential teratogenic effects, though data are limited. Animal studies have shown fetal harm. Use only if clearly needed. |
| 2nd trimester | Use with caution in the second trimester; may cause maternal respiratory depression and fetal bradycardia. Benefits must outweigh risks. |
| 3rd trimester | Avoid near term as it may cause neonatal respiratory depression and withdrawal syndrome. Use only for labor analgesia under close monitoring. |
Clinical note
CNS depressants including alcohol and benzodiazepines increase sedation risk Life-threatening respiratory depression may occur.
| Placental transfer | Sufentanil rapidly crosses the placenta, achieving fetal concentrations approximately 80% of maternal levels. Binding to fetal plasma proteins may be lower than maternal, leading to potential accumulation. |
| Breastfeeding | Sufentanil is excreted into breast milk in low concentrations. However, due to the potential for neonatal opioid toxicity and respiratory depression, breastfeeding is generally not recommended during maternal use. If used, monitor infant for sedation and feeding difficulties. |
■ FDA Black Box Warning
Risk of respiratory depression, especially in elderly, cachectic, or debilitated patients; risk of addiction, abuse, and misuse; risk of neonatal opioid withdrawal syndrome with prolonged use during pregnancy; risk of interactions with CNS depressants including alcohol; risk of hypotension and bradycardia in patients with compromised cardiovascular function.
| Common Effects | analgesia |
| Serious Effects |
Hypersensitivity to sufentanil or any componentSignificant respiratory depression (in unmonitored settings)Acute or severe bronchial asthmaKnown or suspected gastrointestinal obstruction (including paralytic ileus)Concurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of stoppingMyasthenia gravis (relative, but absolute in some sources)
| Precautions | Monitor respiratory function closely; use with caution in patients with head injury, increased intracranial pressure, or respiratory conditions; may cause muscle rigidity, especially with rapid IV administration; avoid abrupt discontinuation after prolonged use; use with caution in patients with hepatic or renal impairment; concomitant use with other CNS depressants increases risk of adverse effects. |
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| Lactation Rating | L4 (Possibly Hazardous) |
| Teratogenic Risk | Sufentanil citrate is classified as FDA Pregnancy Category C. Animal studies have shown fetal harm, but no adequate human studies exist. First trimester: Potential for teratogenic effects based on animal data; use only if benefit outweighs risk. Second and third trimesters: Risk of fetal respiratory depression and maternal opioid withdrawal if used chronically. Use near term may cause neonatal opioid withdrawal syndrome. |
| Fetal Monitoring | Monitor maternal respiratory rate, oxygen saturation, heart rate, blood pressure, and sedation level. Fetal heart rate monitoring is recommended during prolonged use or near term. Observe neonate for respiratory depression, hypotonia, and withdrawal symptoms. |
| Fertility Effects | Sufentanil may impair male and female fertility based on animal studies. In humans, chronic opioid use can lead to hypogonadism, menstrual irregularities, and reduced libido. Acute use has unclear effects on fertility. |
| Food/Dietary | No known food interactions. However, patients should avoid alcohol and grapefruit juice as they may potentiate central nervous system depression. |
| Clinical Pearls | Sufentanil citrate is 5-10 times more potent than fentanyl and 500-1000 times more potent than morphine. It has a rapid onset (1-3 min) and short duration of action (15-30 min) due to redistribution. Use with caution in patients with bradycardia or hypovolemia. Naloxone reverses respiratory depression but may cause acute withdrawal. Monitor for chest wall rigidity during rapid IV administration; pretreat with a neuromuscular blocker if needed. Hepatic impairment prolongs half-life. Accumulation occurs with repeated doses due to long elimination half-life (2-4 hours). |
| Patient Advice | You will receive this medication only under direct supervision of a healthcare provider in a hospital setting. · This drug may cause drowsiness, dizziness, or blurred vision; do not drive or operate machinery until effects are fully resolved. · Notify your doctor if you have a history of head injury, breathing problems, liver disease, or alcohol/substance abuse. · Avoid alcohol and any other central nervous system depressants after receiving this medication. · If you experience slow or shallow breathing, severe drowsiness, or difficulty awakening, seek immediate medical attention. |