Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ALFENTANIL vs BAFIERTAM
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.
BAFIERTAM (monomethyl fumarate) is a prodrug that is rapidly hydrolyzed to monomethyl fumarate, which activates the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway, leading to upregulation of antioxidant response elements and cytoprotective proteins. It also modulates immune responses by shifting from a pro-inflammatory to an anti-inflammatory state.
Analgesic adjunct during general anesthesia,Induction of anesthesia,Maintenance of anesthesia for short surgical procedures,Off-label: Procedural sedation in monitored settings
FDA-approved: Treatment of relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease.,Off-label: None widely documented.
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.
120 mg orally once daily.
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.
Approximately 12 hours (range 8–15 hours); permits twice-daily dosing in multiple sclerosis.
Alfentanil is primarily metabolized by hepatic cytochrome P450 enzymes, mainly CYP3A4, through oxidative N-dealkylation and O-demethylation to inactive metabolites.
BAFIERTAM is a prodrug that is rapidly metabolized by esterases in the gastrointestinal tract, blood, and tissues to monomethyl fumarate. Monomethyl fumarate is further metabolized via the tricarboxylic acid (TCA) cycle, with no significant involvement of cytochrome P450 enzymes.
Primarily hepatic metabolism via CYP3A4; <1% excreted unchanged in urine; metabolites (mainly noralfentanil) excreted renally. Biliary/fecal excretion of metabolites accounts for ~30%.
Primarily via renal excretion as unchanged drug (approximately 80% of the dose); minimal biliary/fecal elimination (<5%).
~92% bound primarily to alpha-1-acid glycoprotein (AAG) and albumin.
30–40% 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.
Approximately 0.5–0.7 L/kg; indicates distribution into total body water with limited tissue binding.
IV: 100%. IM: ~90%. Epidural: ~30–50% due to local uptake and redistribution. No significant oral bioavailability.
Oral: Approximately 50% (due to first-pass metabolism); administer with food to reduce GI irritation.
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.
No dose adjustment required for GFR ≥30 m L/min. Not recommended for GFR <30 m L/min.
Child-Pugh class A: no adjustment needed; Child-Pugh class B: reduce dose by 50%; Child-Pugh class C: reduce dose by 75%.
Use with caution in hepatic impairment; reduce dose to 60 mg once daily in Child-Pugh Class B or C.
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.
Not established in pediatric patients.
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; use with caution due to age-related decline in renal function.
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.
No black box warning.
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.
Lymphopenia: May cause reduction in lymphocyte counts; monitor complete blood count before and periodically during treatment.,Hypersensitivity reactions: Anaphylaxis and angioedema may occur; discontinue if severe.,Progressive multifocal leukoencephalopathy (PML): Reported in patients with prolonged lymphopenia; consider holding therapy if lymphocyte counts drop below 0.2 x 10^9/L.,Hepatic injury: Elevations of liver enzymes have been reported; monitor in patients with pre-existing liver disease.,Flushing and gastrointestinal events: Common; may be managed by taking with food or using aspirin.
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)
Known hypersensitivity to BAFIERTAM, monomethyl fumarate, or any excipient.,Concomitant use with dimethyl fumarate or other fumaric acid esters.
No significant food interactions known. Avoid grapefruit and grapefruit juice as they may inhibit CYP3A4 metabolism, potentially prolonging effects.
Administer with food to reduce flushing and gastrointestinal adverse effects. Avoid alcohol consumption during treatment as it may exacerbate flushing. No specific dietary restrictions are required.
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.
BAFIERTAM (monomethyl fumarate) is contraindicated in pregnancy. Animal studies show malformations at subclinical doses. No human data; avoid in all trimesters due to teratogenic potential.
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.
No data on presence in human milk. M/P ratio unknown. Risk of infant exposure cannot be excluded. Discontinue breastfeeding or drug, considering importance to mother.
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.
No dose adjustment data; contraindicated in pregnancy. If unintentional exposure occurs, discontinue immediately. Pharmacokinetic changes unknown but drug should not be used.
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.
BAFIERTAM (monomethyl fumarate) is a prodrug of monomethyl fumarate, indicated for relapsing forms of multiple sclerosis. Administer with food to reduce flushing and gastrointestinal adverse effects. Titrate as per recommended schedule to improve tolerability. Monitor complete blood count, liver function tests, and renal function at baseline and periodically. Flushing may be reduced by taking with food or using non-enteric coated aspirin (325 mg) 30 minutes prior. Avoid concurrent use with dimethyl fumarate or other fumaric acid esters.
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.
Take BAFIERTAM exactly as prescribed, usually twice daily with food.,Flushing and gastrointestinal upset are common but may decrease over time; taking with food and gradual dose titration helps.,Do not crush, chew, or open capsules; swallow whole.,Report any signs of infection, unusual bruising or bleeding, or severe abdominal pain to your healthcare provider.,Avoid consuming alcohol, as it may increase flushing risk.,If you miss a dose, take it as soon as you remember unless it is near the time of the next dose; do not double up.,Inform all healthcare providers that you are taking BAFIERTAM.
"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 BAFIERTAM, 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.. BAFIERTAM is a Iron Chelating Agent that works by BAFIERTAM (monomethyl fumarate) is a prodrug that is rapidly hydrolyzed to monomethyl fumarate, which activates the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway, leading to upregulation of antioxidant response elements and cytoprotective proteins. It also modulates immune responses by shifting from a pro-inflammatory to an anti-inflammatory state.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ALFENTANIL and BAFIERTAM 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 BAFIERTAM is: 120 mg orally once daily.. 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 BAFIERTAM 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. BAFIERTAM is classified as Category C. BAFIERTAM (monomethyl fumarate) is contraindicated in pregnancy. Animal studies show malformations at subclinical doses. No human data; avoid in all trimesters due to teratogenic p. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.