Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (1,342 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
A short-acting opioid anesthetic and analgesic derivative of fentanyl. It produces an early peak analgesic effect and fast recovery of consciousness. Alfentanil is effective as an anesthetic during surgery, for supplementation of analgesia during surgical procedures, and as an analgesic for critically ill patients.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Alfentanyl; Alfenta; Rapifen; Limifen; Alfentanil Hydrochloride; R-39209; R39209; R 39209.
Where it fits in the MeSH classification
- Broader topics
- Fentanyl
Related concepts
Research landscape
PubMed indexes 1,775 records tagged with the MeSH heading “Alfentanil” (counts retrieved 2026-10-31). 114 of them (6.4%) were published from 2020 onward, and the busiest period so far is through 1999 with 1,180 records.
Reviews account for 63 records (3.5%) and meta-analyses for 10. Randomized controlled trials number 677 (38.1%) as a share of all records on the topic. Randomized trials make up a comparatively large share of this literature, which means many treatment questions have been tested directly.
Show the data
| Period | Records |
|---|---|
| through 1999 | 1,180 |
| 2000-2009 | 331 |
| 2010-2019 | 150 |
| 2020 onward | 114 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 63 | 3.5% |
| Meta-analyses | 10 | 0.6% |
| Randomized controlled trials | 677 | 38.1% |
Method: PubMed query "Alfentanil"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in drugs and chemicals
Studies of a chemical or drug can answer very different questions: what it is and how it behaves in cells and animals, how the body handles it, and whether it changes outcomes in people. Laboratory and animal findings often do not carry over to patients, and observational studies of exposures are confounded by who uses a substance and why. Nothing on this page is a recommendation to use, avoid, start or stop any substance or medicine; talk to a qualified clinician or pharmacist about your own situation. Check the dose, the species, the comparison group and whether a patient-relevant outcome was measured.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
Sedative effect of remimazolam combined with alfentanil in colonoscopic polypectomy: a prospective, randomized, controlled clinical trial [1]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundRemimazolam is a newer benzodiazepine with properties of rapid onset, short duration of action, and fast recovery.
- Closing excerpt
- Trial registrationThe clinical trial was registered on (16/05/2021, ChiCTR2100046492).
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (230 words)
BackgroundRemimazolam is a newer benzodiazepine with properties of rapid onset, short duration of action, and fast recovery. Our study was to evaluate the effects of different doses of remimazolam combined with alfentanil in colonoscopic polypectomy.MethodsOne hundred twenty patients were randomly divided into four groups: alfentanil and propofol (AP) group, alfentanil and remimazolam 0.1 mg/kg (AR1 group), 0.15 mg/kg (AR2 group), or 0.2 mg/kg (AR3 group). Patients in the four groups received alfentanil 10 μg/kg, followed by propofol 2 mg/kg and three dosages of remimazolam. Modified Observer's Assessment of Alertness and Sedation (MOAA/S) scale, heart rate (HR), oxygen saturation (SpO2), respiratory rate (RR), bispectral index (BIS) values and mean arterial pressure (MAP) were collected at intervals of 5 min and analyzed at different time points: before anesthesia (T0), 5 min (T1), 10 min (T2), 15 min after anesthesia (T3) and at the end of surgery (T4). The average MAP was calculated utilizing the average of all MAP values. The primary outcome was the success rate of sedation. Secondary outcomes included time to full alert and adverse events.ResultsThe success rate of sedation was 100% among the four groups. The incidence of hypotension was significantly decreased (all P ConclusionsRemimazolam combined with alfentanil have a non-inferior sedative effect than propofol during the colonoscopic polypectomy. Moreover, this combination of two short-acting drugs might be a safer alternative.Trial registrationThe clinical trial was registered on (16/05/2021, ChiCTR2100046492).
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 35974309 · DOI · PMC9380378
Efficacy and Safety of Remimazolam Besylate Combined with Alfentanil in Painless Gastroscopy: A Randomized, Single-Blind, Parallel Controlled Study [2]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe efficacy and adverse reactions of remimazolam besylate (RB) in combination with alfentanil in patients with painless gastroscopy remain unclear.
- Closing excerpt
- However, the cases involved in this study are all from a single-center data, which requires further multicenter research and conformation.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (351 words)
BackgroundThe efficacy and adverse reactions of remimazolam besylate (RB) in combination with alfentanil in patients with painless gastroscopy remain unclear.ObjectiveThe aim of the study is to observe the efficacy and adverse reactions of RB in combination with alfentanil in patients with painless gastroscopy RB.MethodsAll patients were randomly divided into two groups: RB combined with the alfentanil group (research group) and propofol combined with the alfentanil group (control group). After full oxygen inhalation and electrocardiographic monitoring, the research group was given 10 μg/Kg alfentanil + RB 0.2 mg/kg intravenously, and the control group was given 10 μg/Kg alfentanil + propofol 1.5 mg/kg. If there is a clinical need, the research group was given 2.5 mg/additional RB, whereas the control group was treated with an additional 0.5 mg/kg propofol. Main outcome measures were as follows: The vital endpoints including diachronic changes in heart rate (HR), blood pressure (BP), respiratory rate (RR), blood oxygen saturation (SPO2), end-expiratory carbon dioxide (etCO2), IPI, modified observer's assessment of alert/sedation (MOAA/S), time-related endpoints, perioperative adverse events, endoscopy, and anesthesiologist satisfaction, and 24-hour follow-up of adverse reactions, IPI scores, and satisfaction were recorded.ResultsThe HR and BP of the patients in the research group and the control group decreased, with a greater decrease in the control group, and the difference was statistically significant (p 2, and IPI in the research group and the control group decreased to the lowest at 2-3 min but the decrease in the control group was more significant. Furthermore, there was no significant difference in the time from the completion of administration to 4 minutes of IPI and the total examination time, but the awakening time in the research group was slightly longer than that in the control group, and the difference was statistically significant (p p p p p ConclusionsRB combined with alfentanil can provide safe and effective sedation for patients undergoing painless gastroscopy. Compared with propofol, RB and alfentanil for injection can avoid large hemodynamic fluctuations and deep sedation, and have fewer adverse reactions. However, the cases involved in this study are all from a single-center data, which requires further multicenter research and conformation.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 36263002 · DOI · PMC9553471
Sedation with propofol during ERCP: is the combination with esketamine more effective and safer than with alfentanil? Study protocol for a randomized controlled trial [3]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundEndoscopic retrograde cholangiopancreatography (ERCP) is a gastrointestinal procedure that requires a relatively motionless patient during the intervention.
- Closing excerpt
- Registered on 17 September 2015.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (286 words)
BackgroundEndoscopic retrograde cholangiopancreatography (ERCP) is a gastrointestinal procedure that requires a relatively motionless patient during the intervention. Deep sedation by intravenous propofol combined with an opioid has recently become the preferred sedation technique. However, when high doses of propofol are used, side effects, namely respiratory depression, may occur. Esketamine has hypnotic, analgesic, and sympathomimetic effects. Our assumption is that a combination of propofol with esketamine reduces the dosage of individual drugs, thereby minimizing sedation side effects while keeping the same satisfaction level of patients and endoscopists.Methods/designThe study will be performed as a randomized controlled multicenter trial. Patients undergoing ERCP, ≥ 18 years old, with American Society of Anesthesiologists (ASA) classification I-III will be randomized after written informed consent to group K (propofol/esketamine) or to group A (propofol/alfentanil). The primary outcome, reflecting effectiveness of sedation, is the total dose of propofol. Secondary outcome parameters are patients' and endoscopists' satisfaction with the procedure and the number of sedation-related pulmonary and cardiovascular events. Data on sedation-related events are collected by recording of oxygen saturation (SpO2), respiratory rate (RR), end-tidal CO2 (etCO2), heart rate (HR), arrhythmias (electrocardiogram (ECG)), and non-invasive blood pressure (NIBP) measurements. Satisfaction parameters are collected by means of questionnaires before and after the procedure and on the following day.DiscussionEsketamine is known for its effective anesthetic and analgesic effects maintaining spontaneous breathing and airway reflexes. Due to an increase in sympathetic tone, hypotension and cardiac depression is less common. Unfortunately esketamine is also known for its psychotomimetic effects. We aim to demonstrate that the combination of esketamine with propofol for sedation in patients subjected to ERCP interventions is nevertheless superior to a combination of propofol with an opioid.Trial registrationNederland's Trial Register, NTR5486 . Registered on 17 September 2015.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 29020995 · DOI · PMC5637240
The median Effective Dose (ED50) and the 95% Effective Dose (ED95) of alfentanil in inhibiting responses to cervical dilation when combined with ciprofol during hysteroscopic procedure: a prospective, double-blind, dose-finding clinical study [4]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundAlfentanil, a short-acting µ opioid receptor agonist, has recently been confirmed that when combined with propofol for daytime hysteroscopy, it provided more stable hemodynamics compared with sufentanil, and has a lower incidence of hypoxemia and postoperative nausea and vomiting.
- Closing excerpt
- Trial registrationThe study was then registered on January 24, 2024 at the Chinese Clinical Trial Registry which participates in the World Health Organization International Clinical Trials Registry Platform (Identifier: ChiCTR2400080232) before enrolling the first participant and written informed consent was obtained by each patient.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (475 words)
BackgroundAlfentanil, a short-acting µ opioid receptor agonist, has recently been confirmed that when combined with propofol for daytime hysteroscopy, it provided more stable hemodynamics compared with sufentanil, and has a lower incidence of hypoxemia and postoperative nausea and vomiting. The object of the trial was to determine the median effective dose (ED50) and the 95% effective dose (ED95) of alfentanil in inhibiting responses to cervical dilation when combined with ciprofol and explore the effect of alfentanil on reducing ciprofol requirement during hysteroscopy.MethodsOne hundred and forty patients scheduled hysteroscopy under monitored anesthesia care were randomized to receive a bolus of 8 µg·kg-1, 10 µg·kg-1, 12 µg·kg-1, 14 µg·kg-1 intravenous alfentanil or 0.15 µg⋅kg-1 intravenous sufentanil followed by a bolus of 0.5 mg·kg-1 ciprofol. Whether there was loss of response to cervical dilation or not in each patient was recorded. We used the probit analysis to determine ED50 and ED95 of alfentanil in inhibiting responses to cervical dilation when combined with ciprofol. The requirement of ciprofol, the emergence time, the visual analogue scale score of pain at five time points, and the incidence of adverse events were recorded.ResultsThe calculated ED50 and ED95 of alfentanil were 9.73 [95% CI 8.57 to 10.56] µg·kg-1 and 15.02 [95% CI 13.57 to 18.12] µg·kg-1, respectively. Ciprofol requirements were lower in patients given 10 µg·kg-1 (0.795 [ 0.707 to 0.889] mg·kg-1), 12 µg·kg-1 (0.799 [0.601 to 0.913] mg·kg-1), and 14 µg·kg-1 (0.789 [0.660 to 0.968] mg·kg-1) alfentanil than those given 8 µg·kg-1 alfentanil (1.082 [ 0.853 to 1.271] mg·kg-1) alfentanil and 0.15 µg⋅kg-1 sufentanil (1.046 [0.861 to 1.427] mg·kg-1) (P -1 (0.9 [0.8 to 1.2] min), 12 µg·kg-1 (0.8 [0.6 to 1.0] min) than those given 8 µg·kg-1 (1.9 [1.0 to 2.8] min) and 14 µg·kg-1 (1.5 [1.0 to 2.3] min) alfentanil, and 0.15 µg·kg-1 sufentanil (1.4 [1.0 to 2.0] min) (P -1, 12 µg·kg-1, and 14 µg·kg-1 alfentanil when compared with 8 µg·kg-1 alfentanil and 0.15 µg⋅kg-1 sufentanil (P -1, 10 µg·kg-1, 12 µg·kg-1 alfentanil, and 14 µg·kg-1 alfentanil than those given 0.15 µg·kg-1 sufentanil (P = 0.044), while the incidence of intraoperative desaturation was higher in patients given 14 µg·kg-1 alfentanil than those given 8 µg·kg-1, 10 µg·kg-1, and 12 µg·kg-1 alfentanil, and 0.15 µg·kg-1 sufentanil (P ConclusionsFor women undergoing hysteroscopic surgery, a dose of 10-12 µg·kg-1 of alfentanil was associated with significant ciprofol-sparing effect, earlier anesthesia emergence, better postoperative analgesia, and less unexpected hemodynamic events compared with sufentanil, but 14 µg·kg-1 alfentanil had the risk of transient desaturation and delayed anesthesia recovery. Indications and the optimal dose of alfentanil in this patient population need further clarification.Trial registrationThe study was then registered on January 24, 2024 at the Chinese Clinical Trial Registry which participates in the World Health Organization International Clinical Trials Registry Platform (Identifier: ChiCTR2400080232) before enrolling the first participant and written informed consent was obtained by each patient.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40684098 · DOI · PMC12275378
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Clinical pharmacokinetics of alfentanil, fentanyl and sufentanil. An update [5]
- Research article Identification of the pharmacogenetic determinants of alfentanil metabolism: cytochrome P-450 3A4. An explanation of the variable elimination clearance [6]
- Research article Comparison of Fentanyl, Remifentanil, Sufentanil and Alfentanil in Combination with Propofol for General Anesthesia: A Systematic Review and Meta-analysis of Randomized Controlled Trials [7]
- Research article Clinical uses of fentanyl, sufentanil, and alfentanil [8]
- Research article Pharmacodynamics, pharmacokinetics, and clinical uses of fentanyl, sufentanil, and alfentanil [9]
- Research article Prolonged alfentanil effect following erythromycin administration [10]
References
- Xin Y, Chu T, Wang J, Xu A. Sedative effect of remimazolam combined with alfentanil in colonoscopic polypectomy: a prospective, randomized, controlled clinical trial. . 2022. PMID 35974309 · DOI · PMC9380378
- Xu C, He L, Ren J, Zhou J, Guo H, Chen N, et al.. Efficacy and Safety of Remimazolam Besylate Combined with Alfentanil in Painless Gastroscopy: A Randomized, Single-Blind, Parallel Controlled Study. . 2022. PMID 36263002 · DOI · PMC9553471
- Eberl S, Koers L, van Hooft JE, de Jong E, Schneider T, Hollmann MW, et al.. Sedation with propofol during ERCP: is the combination with esketamine more effective and safer than with alfentanil? Study protocol for a randomized controlled trial. . 2017. PMID 29020995 · DOI · PMC5637240
- Gao R, Li SX, Zhou YH, Xing L, Fu JP, Shen JJ, et al.. The median Effective Dose (ED50) and the 95% Effective Dose (ED95) of alfentanil in inhibiting responses to cervical dilation when combined with ciprofol during hysteroscopic procedure: a prospective, double-blind, dose-finding clinical study. . 2025. PMID 40684098 · DOI · PMC12275378
- Scholz J, Steinfath M, Schulz M. Clinical pharmacokinetics of alfentanil, fentanyl and sufentanil. An update. Clin Pharmacokinet. 1996. PMID 8896944 · DOI
- Yun CH, Wood M, Wood AJ, Guengerich FP. Identification of the pharmacogenetic determinants of alfentanil metabolism: cytochrome P-450 3A4. An explanation of the variable elimination clearance. Anesthesiology. 1992. PMID 1519785 · DOI
- Sridharan K, Sivaramakrishnan G. Comparison of Fentanyl, Remifentanil, Sufentanil and Alfentanil in Combination with Propofol for General Anesthesia: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Curr Clin Pharmacol. 2019. PMID 30868958 · DOI · PMC7011685
- Clotz MA, Nahata MC. Clinical uses of fentanyl, sufentanil, and alfentanil. Clin Pharm. 1991. PMID 1834393 · DOI
- Willens JS, Myslinski NR. Pharmacodynamics, pharmacokinetics, and clinical uses of fentanyl, sufentanil, and alfentanil. Heart Lung. 1993. PMID 8387987
- Bartkowski RR, McDonnell TE. Prolonged alfentanil effect following erythromycin administration. Anesthesiology. 1990. PMID 2203286 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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