Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
LUPKYNIS vs ALFENTA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Calcineurin inhibitor immunosuppressant that binds to cyclophilin A, inhibiting calcineurin activity, which prevents dephosphorylation and activation of nuclear factor of activated T-cells (NFAT), thereby reducing cytokine production and T-cell activation.
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.
Treatment of lupus nephritis in combination with a background immunosuppressive therapy
Induction and maintenance of anesthesia,Analgesic supplement during surgical procedures,Intravenous use for monitored anesthesia care (MAC)
23.7 mg orally twice daily with food.
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.
Terminal elimination half-life approximately 30 hours; supports once-daily dosing; steady-state reached by day 4.
Terminal elimination half-life: 90–111 minutes (1.5–1.85 hours); prolonged in hepatic impairment.
Primarily metabolized by CYP3A4; minor contribution from CYP3A5.
Hepatic via CYP3A4 to inactive metabolites; major metabolite is desmethylalfentanil (inactive).
Primarily hepatic metabolism; <1% excreted unchanged in urine; approximately 66% of total radioactivity recovered in feces (mainly metabolites) and 22% in urine (mainly metabolites).
Primarily renal (urinary) elimination as metabolites; approximately 80% recovered in urine, 20% in feces.
Greater than 99% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein.
Approximately 92% bound, primarily to alpha-1 acid glycoprotein and albumin.
Apparent Vd/F ~24 L (approximately 0.34 L/kg assuming 70 kg); indicates distribution into tissues.
0.5–1.0 L/kg; reflects moderate tissue distribution; higher Vd in neonates and elderly.
Oral bioavailability approximately 35% (range 20–50%) under fasting conditions; high-fat meal reduces Cmax and AUC by about 50%.
Intravenous: 100%; intramuscular: approximately 90%; intrathecal: approximately 10% (due to systemic absorption following spinal administration).
No dose adjustment required for GFR ≥30 m L/min. Avoid use in severe renal impairment (GFR <30 m L/min) due to lack of data.
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.
Child-Pugh Class A: No adjustment. Child-Pugh Class B: Reduce dose to 15.8 mg orally twice daily. Child-Pugh Class C: Not recommended.
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.
Safety and efficacy not established in pediatric patients; no approved dose.
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.
No specific dose adjustment required; monitor renal function due to age-related decline.
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.
Increased risk of infection and lymphoma; increased risk of nephrotoxicity and hypertension; increased risk of neurotoxicity.
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.
Nephrotoxicity and hypertension require regular monitoring. Neurotoxicity including posterior reversible encephalopathy syndrome (PRES). Increased susceptibility to infections including opportunistic infections. Malignancies including lymphoma. Monitor for Epstein-Barr virus serology. Use with caution with CYP3A4 inhibitors and inducers. Avoid live vaccines.
Respiratory depression; abuse potential; hypotension; bradycardia; muscle rigidity; serotonin syndrome with concurrent serotonergic drugs; adrenal insufficiency; risk of withdrawal with prolonged use.
Concurrent use with chronic immunosuppressive therapies other than mycophenolate mofetil (MMF) or mycophenolic acid (MPA). Known hypersensitivity to voclosporin or any component of the formulation.
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).
Avoid grapefruit and grapefruit juice as they increase voclosporin exposure. No other specific food interactions are known.
No known interactions with food. However, grapefruit juice may increase alfentanil serum concentrations due to CYP3A4 inhibition; avoid concurrent consumption.
LUPKYNIS (voclosporin) is a calcineurin inhibitor. Based on animal studies, there is a risk of fetal harm in all trimesters. In rats and rabbits, voclosporin administration during organogenesis resulted in increased embryofetal mortality and reduced fetal weight at maternally toxic doses. There are no adequate human studies. Avoid use during pregnancy unless potential benefit outweighs risk.
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.
It is unknown if voclosporin is excreted in human milk. In animal studies, voclosporin and its metabolites were detected in milk of lactating rats. No M/P ratio available for humans. Due to potential for serious adverse reactions in nursing infants, advise women not to breastfeed during treatment and for 4 weeks after last dose.
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.
No specific dose adjustments are established for pregnancy. However, pregnancy can increase voclosporin clearance due to expanded plasma volume and enhanced metabolism. Consider therapeutic drug monitoring if available, and adjust dose to maintain therapeutic trough levels (target 30-60 ng/m L) as needed.
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.
Monitor for hematuria, proteinuria, and e GFR during treatment. Lupkynis (voclosporin) is a calcineurin inhibitor; do not co-administer with other CNIs or strong CYP3A4 inhibitors. Reduce dose in patients with e GFR <45 m L/min per 1.73 m². Concomitant use with mycophenolate mofetil and corticosteroids is standard. Check blood pressure and serum potassium regularly. Live vaccines contraindicated.
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.
Take exactly as prescribed; do not stop or change dose without consulting your doctor.,You will need regular blood and urine tests to monitor kidney function and drug levels.,Report any signs of infection (fever, sore throat), high blood pressure (severe headache, vision changes), or changes in urine output/color.,Avoid grapefruit and grapefruit juice during treatment.,Do not receive live vaccines while taking this medication.,Use effective contraception during treatment and for 12 weeks after last dose if of childbearing potential.,Tell your doctor about all medications, including over-the-counter drugs and supplements.
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.
No interactions on record
"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."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about LUPKYNIS vs ALFENTA, answered by our medical review team.
LUPKYNIS is a Calcineurin Inhibitor Immunosuppressant that works by Calcineurin inhibitor immunosuppressant that binds to cyclophilin A, inhibiting calcineurin activity, which prevents dephosphorylation and activation of nuclear factor of activated T-cells (NFAT), thereby reducing cytokine production and T-cell activation.. 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.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between LUPKYNIS and ALFENTA 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 LUPKYNIS is: 23.7 mg orally twice daily with food.. 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.. 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 LUPKYNIS and ALFENTA 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. LUPKYNIS is classified as Category C. LUPKYNIS (voclosporin) is a calcineurin inhibitor. Based on animal studies, there is a risk of fetal harm in all trimesters. In rats and rabbits, voclosporin administration during . 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. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.