Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ALFENTA vs REVLIMID
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
μ-opioid receptor agonist that activates G-protein coupled receptors to inhibit adenylate cyclase, decreasing c AMP production, leading to reduced neuronal excitability and pain transmission.
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.
Induction and maintenance of anesthesia,Analgesic supplement during surgical procedures,Intravenous use for monitored anesthesia care (MAC)
Multiple myeloma (in combination with dexamethasone),Myelodysplastic syndromes (MDS) associated with deletion 5q abnormality,Mantle cell lymphoma,Follicular lymphoma (in combination with rituximab)
Intravenous: Initial dose 8-20 mcg/kg (0.5-1 min) then 0.5-3 mcg/kg/min or 3-5 mcg/kg q5-20min. For short procedures: 8-20 mcg/kg. For longer procedures: 50-75 mcg/kg followed by 0.5-3 mcg/kg/min.
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); prolonged in hepatic impairment.
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).
Hepatic via CYP3A4 to inactive metabolites; major metabolite is desmethylalfentanil (inactive).
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 renal (urinary) elimination as metabolites; approximately 80% recovered in urine, 20% in feces.
Primarily renal excretion as unchanged drug (approximately 67% of the dose in urine over 24 hours) with minor fecal elimination (<4%).
Approximately 92% bound, primarily to alpha-1 acid glycoprotein and albumin.
Approximately 30% bound to plasma proteins, primarily albumin.
0.5–1.0 L/kg; reflects moderate tissue distribution; higher Vd in neonates and elderly.
Volume of distribution (Vd) is approximately 0.6-1.0 L/kg, indicating distribution into total body water and some tissue binding.
Intravenous: 100%; intramuscular: approximately 90%; intrathecal: approximately 10% (due to systemic absorption following spinal administration).
Absolute oral bioavailability is approximately 33% (range 20-50%) due to first-pass metabolism. Food does not significantly alter bioavailability.
No specific dose adjustment is recommended for renal impairment; however, alfentanil is primarily metabolized in the liver and its pharmacokinetics are not significantly altered in renal failure.
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.
In hepatic impairment (Child-Pugh class A, B, C): Reduce dose by 50% and titrate carefully due to prolonged elimination half-life. Consider lower initial doses and extended dosing intervals.
No specific Child-Pugh based dose adjustments provided in labeling; use caution and monitor for toxicity in hepatic impairment.
Children (1-12 years): Induction of anesthesia: 10-20 mcg/kg IV; maintenance: 5-10 mcg/kg IV or infusion 0.5-1 mcg/kg/min. For neonates and infants: Dose individualization required; titrate to effect.
Safety and efficacy not established; not recommended for pediatric use outside clinical trials.
Elderly patients (>65 years): Reduce initial dose by 30-50% and administer slowly. Due to decreased clearance and increased sensitivity, lower infusion rates (e.g., 0.3-0.5 mcg/kg/min) may be needed.
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, particularly in elderly or debilitated patients. Concomitant use with benzodiazepines or other CNS depressants may cause profound sedation, respiratory depression, coma, and death.
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; abuse potential; hypotension; bradycardia; muscle rigidity; serotonin syndrome with concurrent serotonergic drugs; adrenal insufficiency; risk of withdrawal with prolonged use.
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 or any component; significant respiratory insufficiency; severe asthma; paralytic ileus; concurrent use of MAOIs (or within 14 days); acute or postoperative pain management in children (except for procedural sedation).
Pregnancy (due to teratogenicity),Women of childbearing potential not using effective contraception,Hypersensitivity to lenalidomide or any component of the formulation
No known interactions with food. However, grapefruit juice may increase alfentanil serum concentrations due to CYP3A4 inhibition; avoid concurrent consumption.
Avoid grapefruit and grapefruit juice; they may increase lenalidomide exposure. No other significant food interactions are known.
Alfentanil, a short-acting opioid analgesic, is classified as FDA Pregnancy Category C. No well-controlled studies in pregnant women exist. In animal studies, no teratogenic effects were observed at clinically relevant doses; however, high doses caused embryotoxicity and increased fetal mortality. Trimester-specific risks: First trimester - potential for minor malformations based on limited human data; second trimester - possible risk if used chronically; third trimester - prolonged use may lead to neonatal respiratory depression, withdrawal syndrome, or opioid dependence. Use only if benefits outweigh risks.
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 human breast milk in low concentrations. The milk-to-plasma (M/P) ratio is approximately 0.3. Estimated infant dose is <1% of maternal weight-adjusted dose, which is considered clinically insignificant. However, due to potential for neonatal opioid effects, caution is advised; monitor infant for drowsiness, respiratory depression, and feeding difficulties. Consider alternative analgesics with established safety profiles, such as acetaminophen or ibuprofen, for lactation.
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 pharmacokinetics of alfentanil. Increased plasma volume and distribution may require higher doses to achieve same effect, while decreased plasma protein binding may increase free fraction, potentiating effects. Alpha-1-acid glycoprotein levels change in pregnancy, affecting binding. In third trimester, clearance may be increased by up to 50% due to enhanced hepatic metabolism. Therefore, dose adjustments may be needed: consider starting at low dose and titrating to effect, with close monitoring. For intravenous administration, typical adult doses (5-20 μg/kg) may need adjustments; no standard pregnancy-specific dosing exists. Use the lowest effective dose for the shortest duration. In labor, avoid high doses prior to delivery due to risk of neonatal respiratory depression.
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, rapid-onset, short-acting opioid analgesic used primarily for induction and maintenance of anesthesia. Due to its high protein binding (90%) and rapid redistribution, it has a shorter duration of action than fentanyl, making it suitable for brief, painful procedures. It undergoes hepatic metabolism via CYP3A4, so concomitant use with CYP3A4 inhibitors like ketoconazole or erythromycin can prolong its effects. Use caution in elderly or hypovolemic patients due to increased risk of hypotension. Naloxone reverses respiratory depression. Alfentanil is 5-10 times less potent than fentanyl.
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 is given only by a healthcare professional in a hospital or surgical setting.,You may feel drowsy, dizzy, or nauseated after receiving this drug.,Report any difficulty breathing or slow heart rate to your healthcare provider immediately.,Avoid alcohol and sedatives for 24 hours after administration, as they can increase side effects.,Do not drive or operate machinery until the effects have fully worn off.
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 ALFENTA vs REVLIMID, answered by our medical review team.
ALFENTA is a Opioid Analgesic that works by μ-opioid receptor agonist that activates G-protein coupled receptors to inhibit adenylate cyclase, decreasing c AMP production, leading to reduced neuronal excitability and pain transmission.. 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 ALFENTA 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 ALFENTA is: Intravenous: Initial dose 8-20 mcg/kg (0.5-1 min) then 0.5-3 mcg/kg/min or 3-5 mcg/kg q5-20min. For short procedures: 8-20 mcg/kg. For longer procedures: 50-75 mcg/kg followed by 0.5-3 mcg/kg/min.. 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 ALFENTA 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. ALFENTA is classified as Category C. Alfentanil, a short-acting opioid analgesic, is classified as FDA Pregnancy Category C. No well-controlled studies in pregnant women exist. In animal studies, no teratogenic effect. 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.