Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ALFENTANIL vs REVLIMID
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Alfentanil is a potent, short-acting synthetic opioid analgesic that primarily acts as a mu-opioid receptor agonist. It binds to mu-opioid receptors in the central nervous system, leading to G-protein coupled activation of inwardly rectifying potassium channels and inhibition of voltage-gated calcium channels, resulting in hyperpolarization and reduced neurotransmitter release. This produces analgesia, sedation, and respiratory depression.
Revlimid (lenalidomide) is an immunomodulatory agent with antiangiogenic and antineoplastic properties. It inhibits tumor necrosis factor-alpha, stimulates T-cell proliferation and IL-2 production, and inhibits angiogenesis by blocking VEGF and b FGF. It also modulates the ubiquitin E3 ligase cereblon, leading to degradation of transcription factors Ikaros and Aiolos, which results in direct tumor cell apoptosis and enhanced immune function.
Analgesic adjunct during general anesthesia,Induction of anesthesia,Maintenance of anesthesia for short surgical procedures,Off-label: Procedural sedation in monitored settings
Multiple myeloma (in combination with dexamethasone),Myelodysplastic syndromes (MDS) associated with deletion 5q abnormality,Mantle cell lymphoma,Follicular lymphoma (in combination with rituximab)
Initial IV bolus of 5-20 mcg/kg; maintenance infusion of 0.5-1.5 mcg/kg/min; incremental boluses of 5-10 mcg/kg as needed. Induction of anesthesia: 50-100 mcg/kg IV.
5-10 mg orally once daily for 21 days of a 28-day cycle; dose depends on indication (e.g., 10 mg for transfusion-dependent anemia due to low- or intermediate-1-risk myelodysplastic syndromes).
Terminal elimination half-life: 90–111 minutes (1.5–1.85 hours). Clinically, context-sensitive half-time is short (~40 min after 3-hour infusion) due to rapid redistribution and metabolism.
Terminal elimination half-life of approximately 3-5 hours in patients with normal renal function. Half-life is prolonged in renal impairment (up to 9 hours in severe impairment).
Alfentanil is primarily metabolized by hepatic cytochrome P450 enzymes, mainly CYP3A4, through oxidative N-dealkylation and O-demethylation to inactive metabolites.
Lenalidomide is primarily metabolized via hydrolysis, with minor involvement of CYP1A2 and CYP3A4. The major route of elimination is renal excretion of unchanged drug; approximately 67% of the dose is excreted unchanged in urine.
Primarily hepatic metabolism via CYP3A4; <1% excreted unchanged in urine; metabolites (mainly noralfentanil) excreted renally. Biliary/fecal excretion of metabolites accounts for ~30%.
Primarily renal excretion as unchanged drug (approximately 67% of the dose in urine over 24 hours) with minor fecal elimination (<4%).
~92% bound primarily to alpha-1-acid glycoprotein (AAG) and albumin.
Approximately 30% bound to plasma proteins, primarily albumin.
Vd: 0.4–1.0 L/kg (mean ~0.75 L/kg). Moderate Vd reflecting rapid distribution to tissues, especially brain and muscle.
Volume of distribution (Vd) is approximately 0.6-1.0 L/kg, indicating distribution into total body water and some tissue binding.
IV: 100%. IM: ~90%. Epidural: ~30–50% due to local uptake and redistribution. No significant oral bioavailability.
Absolute oral bioavailability is approximately 33% (range 20-50%) due to first-pass metabolism. Food does not significantly alter bioavailability.
GFR 10-50 m L/min: administer with caution, consider dose reduction of 25-50%; GFR <10 m L/min: reduce dose by 50% and extend dosing interval.
For Cr Cl ≥60 m L/min: start at 10 mg daily; Cr Cl 30-60 m L/min: start at 5 mg daily; Cr Cl <30 m L/min: 5 mg every other day; for dialysis patients: 5 mg three times weekly after dialysis.
Child-Pugh class A: no adjustment needed; Child-Pugh class B: reduce dose by 50%; Child-Pugh class C: reduce dose by 75%.
No specific Child-Pugh based dose adjustments provided in labeling; use caution and monitor for toxicity in hepatic impairment.
Initial IV bolus of 5-20 mcg/kg; maintenance infusion of 0.5-2 mcg/kg/min. For neonates, reduce dose by 30-50% due to immature clearance.
Safety and efficacy not established; not recommended for pediatric use outside clinical trials.
Reduce initial IV bolus by 30-50% to 3-10 mcg/kg; titrate carefully; monitor for prolonged sedation and respiratory depression.
No specific dose adjustment based solely on age; monitor renal function and adjust per renal guidelines as elderly often have decreased Cr Cl.
Risk of respiratory depression: Alfentanil can cause severe, life-threatening, or fatal respiratory depression. Monitor for respiratory depression, especially during initiation or following dose increases. Accidental ingestion of even one dose can be fatal. Concomitant use with central nervous system depressants (e.g., benzodiazepines, alcohol) may increase risk. Alfentanil is an opioid agonist and a Schedule II controlled substance with high potential for abuse and addiction.
Revlimid (lenalidomide) can cause fetal harm. Women of childbearing potential must use effective contraception and undergo pregnancy testing prior to and during therapy. There is an increased risk of venous thromboembolism, including deep vein thrombosis and pulmonary embolism. The drug is contraindicated in pregnant women.
Respiratory depression: Potentially fatal; monitor oxygenation and ventilation.,Abuse potential: Schedule II controlled substance; risk of addiction, abuse, and diversion.,Concomitant use with CNS depressants: Increases risk of profound sedation, respiratory depression, coma, and death; limit use or monitor closely.,Geriatric and cachectic patients: Increased sensitivity; reduce initial dose.,Hepatic impairment: Alfentanil clearance is reduced in patients with cirrhosis; consider dose adjustment.,Bradycardia and hypotension: Use with caution in patients with hypovolemia or reduced cardiac reserve.,Serotonin syndrome: Risk with concurrent serotonergic drugs (e.g., MAOIs, SSRIs, triptans); monitor for symptoms.,Withdrawal: Prolonged use may lead to physical dependence; taper dose gradually.
Hematologic toxicity: Neutropenia and thrombocytopenia are common, requiring dose adjustments.,Thromboembolism: Increased risk of DVT, PE, and stroke; consider prophylactic anticoagulation or antiplatelet therapy.,Second primary malignancies: Risk of development of other cancers (e.g., AML, MDS) in patients receiving lenalidomide.,Hepatotoxicity: Elevations of liver enzymes have been reported.,Allergic reactions: Including angioedema and Stevens-Johnson syndrome.,Renal impairment: Requires dose adjustment; monitor renal function.
Hypersensitivity to alfentanil, fentanyl, or any opioid,Significant respiratory depression (e.g., acute asthma, COPD in acute exacerbation),Acute or severe bronchial asthma,Suspected or known paralytic ileus,MAO inhibitor use within 14 days (serotonin syndrome risk),Myasthenia gravis (relative contraindication due to risk of respiratory muscle weakness),Morbid obesity with sleep apnea (relative contraindication; increased risk of respiratory depression)
Pregnancy (due to teratogenicity),Women of childbearing potential not using effective contraception,Hypersensitivity to lenalidomide or any component of the formulation
No significant food interactions known. Avoid grapefruit and grapefruit juice as they may inhibit CYP3A4 metabolism, potentially prolonging effects.
Avoid grapefruit and grapefruit juice; they may increase lenalidomide exposure. No other significant food interactions are known.
Alfentanil is an opioid analgesic; limited human data. No clear evidence of major malformations, but third trimester use may cause neonatal opioid withdrawal syndrome (NOWS). Avoid prolonged use or high doses near term; use during labor may cause respiratory depression in neonate.
REVLIMID (lenalidomide) is an analog of thalidomide, a known human teratogen. It is absolutely contraindicated in pregnancy. Fetal exposure can cause severe, life-threatening birth defects including limb reduction, cardiac anomalies, and neural tube defects. Risk is highest during the first trimester but extends throughout gestation.
Alfentanil is excreted into breast milk in very low concentrations; estimated relative infant dose is low (<2% of maternal weight-adjusted dose). M/P ratio not determined in humans. Compatible with breastfeeding with caution; monitor infant for drowsiness, feeding difficulties.
It is unknown if lenalidomide is excreted in human breast milk. Due to the potential for serious adverse reactions in nursing infants, breastfeeding is contraindicated. M/P ratio is not available.
Pregnancy can alter alfentanil pharmacokinetics: increased volume of distribution, decreased plasma clearance, prolonged elimination half-life. Dose reduction may be needed for prolonged use; titrate to effect. During labor, use smallest effective dose.
There are no dose adjustments for pregnancy because the drug is contraindicated; it must be discontinued immediately if pregnancy occurs. No pharmacokinetic studies in pregnancy are available.
Alfentanil is a potent, short-acting synthetic opioid (4-5 times more potent than fentanyl) with rapid onset (1-2 min) and brief duration (5-10 min). Primarily used for induction and maintenance of anesthesia, especially in short procedures. Requires careful monitoring of respiratory depression and chest wall rigidity, particularly during rapid IV administration. Hepatic metabolism (CYP3A4) affected by liver disease; reduce dose. Decrease dose in elderly and hypovolemic patients. Not recommended for chronic pain due to short half-life.
Monitor for thromboembolic events; use with aspirin or anticoagulant prophylaxis. Perform pregnancy tests weekly during first month, then monthly in women of childbearing potential. Dose reduce for Cr Cl <60 m L/min. Avoid in severe hepatic impairment (Child-Pugh C).
This medication causes drowsiness and dizziness; avoid driving or operating machinery for at least 24 hours after administration.,Report any difficulty breathing, chest tightness, or feeling faint immediately.,Alfentanil is used only in hospital settings under direct supervision of healthcare professionals.,Inform your doctor if you have a history of liver disease, lung disease, or drug/alcohol abuse.,Do not consume alcohol or other sedatives while under the effects of alfentanil.
Do not share this medication with others; it can cause severe birth defects.,Use two forms of contraception or abstain from sex during treatment and for 4 weeks after stopping.,Report any new shortness of breath, chest pain, or leg swelling immediately.,Avoid grapefruit and grapefruit juice while taking this medication.,Do not donate blood during treatment and for 4 weeks after stopping.
"Propantheline, an anticholinergic agent, can competitively antagonize muscarinic acetylcholine receptors, potentially reducing gastrointestinal motility and secretion. Alfentanil, a mu-opioid receptor agonist, also decreases gastrointestinal motility through central and peripheral opioid receptors. Concomitant use may synergistically inhibit peristalsis, leading to severe constipation, paralytic ileus, or delayed gastric emptying, which can increase the risk of aspiration and complicate anesthesia recovery."
"Alfentanil, a potent opioid analgesic, can cause significant hypotension and respiratory depression. When combined with furosemide, a loop diuretic that reduces blood volume and vascular resistance, there is a synergistic decrease in blood pressure, which may precipitate cardiovascular collapse, especially in patients with compromised circulatory reserves. Additionally, furosemide may enhance the sedative and respiratory depressant effects of alfentanil, leading to increased risk of respiratory acidosis and altered mental status."
"Alfentanil, a potent mu-opioid receptor agonist, can enhance the bradycardic effects of nebivolol, a beta-1 selective blocker with additional nitric oxide-mediated vasodilation. The combination may lead to excessive slowing of heart rate, reduced cardiac output, and potential hemodynamic instability, particularly in patients with underlying cardiac conduction abnormalities or hypovolemia."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ALFENTANIL vs REVLIMID, answered by our medical review team.
ALFENTANIL is a Opioid Analgesic that works by Alfentanil is a potent, short-acting synthetic opioid analgesic that primarily acts as a mu-opioid receptor agonist. It binds to mu-opioid receptors in the central nervous system, leading to G-protein coupled activation of inwardly rectifying potassium channels and inhibition of voltage-gated calcium channels, resulting in hyperpolarization and reduced neurotransmitter release. This produces analgesia, sedation, and respiratory depression.. REVLIMID is a Immunomodulatory Agent that works by Revlimid (lenalidomide) is an immunomodulatory agent with antiangiogenic and antineoplastic properties. It inhibits tumor necrosis factor-alpha, stimulates T-cell proliferation and IL-2 production, and inhibits angiogenesis by blocking VEGF and b FGF. It also modulates the ubiquitin E3 ligase cereblon, leading to degradation of transcription factors Ikaros and Aiolos, which results in direct tumor cell apoptosis and enhanced immune function.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ALFENTANIL and REVLIMID depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ALFENTANIL is: Initial IV bolus of 5-20 mcg/kg; maintenance infusion of 0.5-1.5 mcg/kg/min; incremental boluses of 5-10 mcg/kg as needed. Induction of anesthesia: 50-100 mcg/kg IV.. The standard adult dose of REVLIMID is: 5-10 mg orally once daily for 21 days of a 28-day cycle; dose depends on indication (e.g., 10 mg for transfusion-dependent anemia due to low- or intermediate-1-risk myelodysplastic syndromes).. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ALFENTANIL and REVLIMID in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ALFENTANIL is classified as Category C. Alfentanil is an opioid analgesic; limited human data. No clear evidence of major malformations, but third trimester use may cause neonatal opioid withdrawal syndrome (NOWS). Avoid. REVLIMID is classified as Category C. REVLIMID (lenalidomide) is an analog of thalidomide, a known human teratogen. It is absolutely contraindicated in pregnancy. Fetal exposure can cause severe, life-threatening birth. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.