(al FEN ta nil)
Analgesia: Analgesic adjunct for the maintenance of anesthesia with barbiturate/nitrous oxide/oxygen; analgesic with nitrous oxide/oxygen in the maintenance of general anesthesia; analgesic component for monitored anesthesia care
Anesthetic: Primary anesthetic for induction of anesthesia in general surgery when endotracheal intubation and mechanical ventilation are required
Hypersensitivity to alfentanil or any component of the formulation or known intolerance to other opioid agonists
Doses should be titrated to appropriate effects; wide range of doses is dependent upon desired degree of analgesia/anesthesia
Anesthesia: Base dose on actual body weight unless >20% above ideal body weight, then base dose on lean body weight.
AlfentanilIndication
Approx Duration of Anesthesia (min)
Induction Period (Initial Dose) (mcg/kg)
Maintenance Period (Increments/ Infusion)
Total Dose (mcg/kg)
Effects
Incremental injection
≤30
8-20
3-5 mcg/kg every 5-20 minutes or 0.5-1 mcg/kg/min
8-40
Spontaneously breathing or assisted ventilation when required.
30-60
20-50
5-15 mcg/kg every 5-20 minutes
Up to 75
Assisted or controlled ventilation required. Attenuation of response to laryngoscopy and intubation.
Continuous infusion
>45
50-75
0.5-3 mcg/kg/min; average infusion rate 1-1.5 mcg/kg/min
Dependent on duration of procedure
Assisted or controlled ventilation required. Some attenuation of response to intubation and incision, with intraoperative stability.
Anesthetic induction
>45
130-245
0.5-1.5 mcg/kg/min or general anesthetic
Dependent on duration of procedure
Assisted or controlled ventilation required. Administer induction dose slowly (over 3 minutes). Concentration of inhalation agents reduced by 30% to 50% for initial hour.
Monitored Anesthesia Care (MAC)
3-8
3-5 mcg/kg every 5-20 minutes or 0.25-1 mcg/kg/min
3-40
Sedation, responsiveness, spontaneously breathing
Table has been converted to the following text.
Adult Dosage Adjustments
Incremental injection in anesthesia ≤30 minutes:
- Initial dose (induction period): 8-20 mcg/kg
- Maintenance period (increments/infusion): 3-5 mcg/kg every 5-20 minutes or 0.5-1 mcg/kg/min
- Total dose: 8-40 mcg/kg
- Appropriate effects: Spontaneously breathing or assisted ventilation when required
Incremental injection in anesthesia of 30-60 minutes:
- Initial dose (induction period): 20-50 mcg/kg
- Maintenance period (increments/infusion): 5-15 mcg/kg every 5-20 minutes
- Total dose: Up to 75 mcg/kg
- Appropriate effects: Assisted or controlled ventilation required. Attenuation of response to laryngoscopy and intubation.
Continuous infusion >45 minutes:
- Initial dose (induction period): 50-75 mcg/kg
- Maintenance period (increments/infusion): 0.5-3mcg/kg/min; average infusion rate: 1-1.5 mcg/kg/min
- Total dose: Dependent on duration of procedure
- Appropriate effects: Assisted or controlled ventilation required. Some attenuation of response to intubation and incision, with intraoperative stability.
Anesthetic induction >45 minutes:
- Initial dose (induction period): 130-245 mcg/kg
- Maintenance period (increments/infusion): 0.5-1.5 mcg/kg/minute or general anesthetic
- Total dose: Dependent on duration of procedure
- Appropriate effects: Assisted or controlled ventilation required. Administer induction dose slowly (over 3 minutes). Concentration of inhalation agents reduced by 30% to 50% for initial hour.
Monitored Anesthesia Care (MAC):
- Initial dose (induction period): 3-8 mcg/kg
- Maintenance period (increments/infusion): 3-5 mcg/kg every 5-20 minutes or 0.25-1 mcg/kg/min
- Total dose: 3-40 mcg/kg
- Appropriate effects: Sedation, responsiveness, spontaneously breathing
Refer to adult dosing. Appropriately reduce the initial dose in elderly patients; consider the effect of the initial dose in determining supplemental doses.
Children <12 years: Dose has not been established.
Children ≥12 years: Refer to adult dosing.
There are no dosage adjustments provided in the manufacturers labeling; use with caution. The pharmacokinetics of alfentanil were evaluated in adult patients with chronic renal failure and compared to patients with normal renal function. Although Vdss was increased in patients with renal failure, elimination half-life was similar between the 2 groups (Chauvin, 1987). Therefore, prolongation of alfentanil duration of action is not expected and dosage adjustment is not necessary.
There are no dosage adjustments provided in the manufacturers labeling; use with caution.
Administer IV slowly over 3 minutes or by IV continuous infusion.
Undiluted injectable: Store at 20 ‚ °C to 25 ‚ °C (68 ‚ °F to 77 ‚ °F). Protect from light.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Injectable, Injection [preservative free]:
Alfenta: 500 mcg/mL (2 mL, 5 mL)
Generic: 500 mcg/mL (2 mL, 5 mL)
Stable in D5W, NS, LR, D5NS.
Y-site administration:
Compatible: Bivalirudin, cisatracurium, dexmedetomidine, etomidate, fenoldopam, hetastarch in lactate electrolyte injection (Hextend), linezolid, propofol, remifentanil.
Incompatible: Amphotericin B cholesteryl sulfate complex, thiopental.
Compatibility in syringe: Compatible: Atracurium, midazolam, morphine, ondansetron
Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy
Alvimopan: Analgesics (Opioid) may enhance the adverse/toxic effect of Alvimopan. This is most notable for patients receiving long-term (i.e., more than 7 days) opiates prior to alvimopan initiation. Management: Alvimopan is contraindicated in patients receiving therapeutic doses of opioids for more than 7 consecutive days immediately prior to alvimopan initiation. Consider therapy modification
Amphetamines: May enhance the analgesic effect of Analgesics (Opioid). Monitor therapy
Anticholinergic Agents: May enhance the adverse/toxic effect of Analgesics (Opioid). Specifically, the risk for constipation and urinary retention may be increased with this combination. Monitor therapy
Antipsychotic Agents (Phenothiazines): May enhance the hypotensive effect of Analgesics (Opioid). Monitor therapy
Aprepitant: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy
Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination
Beta-Blockers: Anilidopiperidine Opioids may enhance the bradycardic effect of Beta-Blockers. Anilidopiperidine Opioids may enhance the hypotensive effect of Beta-Blockers. Monitor therapy
Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification
Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Calcium Channel Blockers (Nondihydropyridine): Anilidopiperidine Opioids may enhance the bradycardic effect of Calcium Channel Blockers (Nondihydropyridine). Anilidopiperidine Opioids may enhance the hypotensive effect of Calcium Channel Blockers (Nondihydropyridine). Monitor therapy
Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Cimetidine: May increase the serum concentration of Alfentanil. Monitor therapy
CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Monitor therapy
Conivaptan: May increase the serum concentration of CYP3A4 Substrates. Avoid combination
Crizotinib: May increase the serum concentration of Alfentanil. Avoid combination
CYP3A4 Inhibitors (Moderate): May decrease the metabolism of CYP3A4 Substrates. Monitor therapy
CYP3A4 Inhibitors (Strong): May decrease the metabolism of CYP3A4 Substrates. Consider therapy modification
Dasatinib: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy
Desmopressin: Analgesics (Opioid) may enhance the adverse/toxic effect of Desmopressin. Monitor therapy
DiazePAM: May enhance the CNS depressant effect of Alfentanil. Hypotension may also occur. Monitor therapy
DiltiaZEM: May increase the serum concentration of Alfentanil. Monitor therapy
Dimethindene: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Diuretics: Analgesics (Opioid) may enhance the adverse/toxic effect of Diuretics. Analgesics (Opioid) may diminish the therapeutic effect of Diuretics. Monitor therapy
Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy
Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (e.g., opioids, barbiturates) with concomitant use. Consider therapy modification
Eluxadoline: Analgesics (Opioid) may enhance the constipating effect of Eluxadoline. Avoid combination
Enzalutamide: May decrease the serum concentration of Alfentanil. Avoid combination
Fluconazole: May increase the serum concentration of Alfentanil. Management: Monitor for increased anesthetic and respiratory depressant effects if alfentanil is combined with fluconazole. Consider using lower initial doses of alfentanil or an alternative anesthetic. Consider therapy modification
Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification
Fosaprepitant: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy
Fusidic Acid (Systemic): May increase the serum concentration of CYP3A4 Substrates. Avoid combination
HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Consider starting with a 20% to 30% lower hydrocodone dose when using together with any other CNS depressant. Dose reductions in the other CNS depressant may also be warranted. Consider therapy modification
HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Idelalisib: May increase the serum concentration of CYP3A4 Substrates. Avoid combination
Ivacaftor: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy
Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy
Luliconazole: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy
Macrolide Antibiotics: May increase the serum concentration of Alfentanil. Management: For patients receiving an interacting macrolide antibiotic, caution should be used in administering alfentanil; monitor for increased anesthetic and respiratory depressant effects. Consider using lower doses of alfentanil or an alternative anesthetic. Exceptions: Azithromycin (Systemic); Fidaxomicin; Roxithromycin; Spiramycin. Consider therapy modification
Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification
MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy
MiFEPRIStone: May increase the serum concentration of CYP3A4 Substrates. Management: Minimize doses of CYP3A4 substrates, and monitor for increased concentrations/toxicity, during and 2 weeks following treatment with mifepristone. Avoid cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus. Consider therapy modification
Minocycline: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Mirtazapine: CNS Depressants may enhance the CNS depressant effect of Mirtazapine. Monitor therapy
Mixed Agonist / Antagonist Opioids: May diminish the analgesic effect of Analgesics (Opioid). Management: Seek alternatives to mixed agonist/antagonist opioids in patients receiving pure opioid agonists, and monitor for symptoms of therapeutic failure/high dose requirements (or withdrawal in opioid-dependent patients) if patients receive these combinations. Avoid combination
Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Nalmefene: May diminish the therapeutic effect of Analgesics (Opioid). Management: Avoid the concomitant use of nalmefene and opioid analgesics. Discontinue nalmefene 1 week prior to any anticipated use of opioid analgesics. If combined, larger doses of opioid analgesics will likely be required. Consider therapy modification
Naltrexone: May diminish the therapeutic effect of Analgesics (Opioid). Management: Seek therapeutic alternatives to opioids. See full drug interaction monograph for detailed recommendations. Consider therapy modification
Netupitant: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy
Ombitasvir, Paritaprevir, Ritonavir, and Dasabuvir: May increase the serum concentration of Alfentanil. Management: Monitor for increased anesthetic and respiratory depressant effects of alfentanil if these agents are combined. Consider using lower initial doses of alfentanil or an alternative anesthetic. Canadian labeling recommends avoidance of this combination. Consider therapy modification
Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination
Osimertinib: May increase the serum concentration of CYP3A4 Substrates. Osimertinib may decrease the serum concentration of CYP3A4 Substrates. Monitor therapy
OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: When oxycodone is combined with another CNS depressant, a dose reduction of one or both agents should be considered. The extended release oxycodone starting dose should be reduced 50% to 67% when initiated in patients already receiving CNS depressants. Consider therapy modification
Palbociclib: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy
Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination
Pegvisomant: Analgesics (Opioid) may diminish the therapeutic effect of Pegvisomant. Monitor therapy
Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification
Piribedil [INT]: CNS Depressants may enhance the CNS depressant effect of Piribedil [INT]. Monitor therapy
Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy
Propofol: Alfentanil may enhance the adverse/toxic effect of Propofol. Specifically the development of opisthotonus (severe hyperextension and spasticity resulting in arching or bridging position) and/or grand mal seizures. Monitor therapy
Ramosetron: Analgesics (Opioid) may enhance the constipating effect of Ramosetron. Monitor therapy
Rifamycin Derivatives: May decrease the serum concentration of Alfentanil. Management: Monitor closely for decreased alfentanil effectiveness. Increased alfentanil doses will likely be needed. Alternatively, changing from alfentanil to a different opioid anesthetic (e.g., sufentanil) may also be considered. Consider therapy modification
ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy
Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy
Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy
Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy
Serotonin Modulators: Analgesics (Opioid) may enhance the serotonergic effect of Serotonin Modulators. This could result in serotonin syndrome. Exceptions: Nicergoline. Monitor therapy
Simeprevir: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy
Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification
Stiripentol: May increase the serum concentration of CYP3A4 Substrates. Management: Use of stiripentol with CYP3A4 substrates that are considered to have a narrow therapeutic index should be avoided due to the increased risk for adverse effects and toxicity. Any CYP3A4 substrate used with stiripentol requires closer monitoring. Consider therapy modification
Succinylcholine: May enhance the bradycardic effect of Analgesics (Opioid). Monitor therapy
Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification
Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Start tapentadol at a dose of one-third to one-half of the normal dose if being initiated in a patient who is taking another drug with CNS depressant effects. Monitor closely for evidence of excessive CNS depression. Consider therapy modification
Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination
Trimeprazine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification
Continuously monitor respiratory rate, oxygen saturation, blood pressure, heart rate; monitor the patient well after surgery because of the risk for delayed effects
>10%:
Cardiovascular: Bradycardia, peripheral vasodilation
Central nervous system: Drowsiness, increased intracranial pressure, sedation
Endocrine & metabolic: Increased release of antidiuretic hormone
Gastrointestinal: Constipation, nausea, vomiting
Ophthalmic: Miosis
1% to 10%:
Cardiovascular: Cardiac arrhythmia, orthostatic hypotension
Central nervous system: Central nervous system depression, confusion
Ophthalmic: Blurred vision
<1% (Limited to important or life-threatening): Biliary tract spasm, bronchospasm, cold and clammy skin, convulsions, delirium, depression, dizziness, drug dependence, dysesthesia, genitourinary tract spasm, laryngospasm, paradoxical central nervous system stimulation, pruritus, respiratory depression, skin rash, urticaria
Reduced plasma clearance and extended terminal elimination may develop.
Reduced plasma clearance and extended terminal elimination may develop.
Concerns related to adverse effects:
- Hypotension: May cause hypotension; use with caution in patients with hypovolemia, cardiovascular disease (including acute MI), or drugs which may exaggerate hypotensive effects (including phenothiazines or general anesthetics).
- Opioid agonist toxicities: Shares the toxic potentials of opioid agonists, and precautions of opioid agonist therapy should be observed.
Disease-related concerns:
- Bradyarrhythmias: Bradycardia has been observed in patients receiving alfentanil; use with caution when administering to patients with bradyarrhythmias. Degree of bradycardia may be more pronounced when administered with non-vagolytic skeletal muscle relaxants (eg, vecuronium, cisatracurium) or when anticholinergic agents (eg, atropine) are not used.
- Drug abuse: Use with caution in patients with a history of drug abuse or acute alcoholism; potential for drug dependency exists. Tolerance, psychological and physical dependence may occur with prolonged use.
- Head trauma: Use with extreme caution in patients with head injury, intracranial lesions, or elevated intracranial pressure; exaggerated elevation of ICP may occur.
- Hepatic impairment: Use with caution in patients with hepatic impairment; duration of action may be prolonged.
- Obesity: Use with caution in patients who are morbidly obese. Use lean body weight for dosing in patients >20% over ideal body weight.
- Renal impairment: Use with caution in patients with renal impairment.
- Respiratory disease: Use with caution in patients with preexisting respiratory compromise (hypoxia and/or hypercapnia), COPD or other obstructive pulmonary disease, and kyphoscoliosis or other skeletal disorder which may alter respiratory function.
- Skeletal muscle rigidity: Skeletal muscle rigidity is related to the dose and rate of administration. Inject slowly over 3 minutes; rapid IV infusion may result in skeletal muscle and chest wall rigidity, impaired ventilation, or respiratory distress/arrest. Initial doses up to 20 mcg/kg may cause skeletal muscle rigidity. Doses >130 mcg/kg will consistently cause muscle rigidity with an immediate onset. Consider the concomitant use of a nondepolarizing skeletal muscle relaxant to decrease the incidence.
Concurrent drug therapy issues:
- Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
Special populations:
- Debilitated patients: Appropriately reduce the initial dose in debilitated patients; consider the effect of the initial dose in determining supplemental doses.
- Elderly: Appropriately reduce the initial dose in elderly patients; consider the effect of the initial dose in determining supplemental doses. Plasma clearance of alfentanil may be reduced and postoperative recovery may be prolonged.
Other warnings/precautions:
- Trained individuals: Due to the high incidence of apnea, hypotension, tachycardia, and muscle rigidity, alfentanil should be administered by individuals specifically trained in the use of anesthetic agents and should not be used in diagnostic or therapeutic procedures outside the monitored anesthesia setting; opioid antagonist, resuscitative and intubation equipment should be readily available.
C
Adverse events were observed in some animal reproduction studies. Alfentanil is known to cross the placenta, which may result in severe respiratory depression in the newborn (Mattingly, 2003). When used for pain relief during labor, opioids may temporarily affect the heart rate of the fetus (ACOG, 2002). Use during labor and delivery is not recommended by the manufacturer.
Binds with stereospecific receptors at many sites within the CNS, increases pain threshold, alters pain perception, inhibits ascending pain pathways; is an ultra short-acting opioid
Vd:
Newborns (premature): 0.5 to 0.6 L/kg (Davis 1988; Marlow 1990)
Children: 0.163 to 0.4 L/kg (Davis 1989; Meistelman 1987)
Adults: 0.4 to 1 L/kg
Hepatic
Only 1% of dose is excreted unchanged; urine (major route of elimination of metabolites)
Rapid, within 5 minutes
Dose dependent: 30 to 60 minutes
Newborns (premature): 5.33 to 9 hours (Davis 1988; Marlow 1990)
Children: 40 to 63 minutes (Davis 1988; Meistelman 1987; Roure 1987)
Adults: 90 to 111 minutes
Neonates: 67%; Adults: 88% to 92%; bound to alpha1-acid glycoprotein
- Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
- Patient may experience fatigue, vomiting, or nausea. Have patient report immediately to prescriber severe dizziness, passing out, bradycardia, tachycardia, arrhythmia, difficult breathing, slow breathing, shallow breathing, confusion, confusion, sexual dysfunction (males), amenorrhea, decreased libido, infertility, signs of adrenal gland problems (severe nausea, vomiting, severe dizziness, passing out, muscle weakness, severe fatigue, mood changes, lack of appetite, or weight loss), or signs of serotonin syndrome (dizziness, severe headache, agitation, hallucinations, tachycardia, abnormal heartbeat, flushing, tremors, sweating a lot, change in balance, severe nausea, or severe diarrhea) (HCAHPS).
- Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.