Penthrox (methoxyflurane) / Medical Developments International - LARVOL DELTA

A Randomized Controlled Trial of Inhaled Methoxyflurane as an Adjunct to Local Anesthesia in Scrotal Urologic Surgery (AUA 2025) - "The results demonstrate that methoxyflurane, as an adjunct to local anesthesia reduces intra-operative pain and anxiety during scrotal surgeries. This combination enhances the overall experience for patients undergoing outpatient urologic procedures. Further research with larger sample sizes is necessary to validate these findings and assess the long-term safety of methoxyflurane in this context."

Clinical • Surgery • Anesthesia • Pain • Psychiatry • Urology

Penthrox®: the use of inhaled methoxyflurane for analgesia in transperineal prostate biopsies (AUA 2025) - "Our study has demonstrated a statistically significant improvement in pain scores in men using Penthrox in addition to standard LA infiltration for transperineal prostate. This has the potential to improve patient's experiences in what can often be the first step of the rocky path of their prostate cancer journey. These promising findings call for a multi-centre blinded randomised trial to investigate this at scale."

Biopsy • Genito-urinary Cancer • Oncology • Pain • Prostate Cancer • Solid Tumor • Urology

A comparative analysis of local anesthesia, nursing-administered conscious sedation, and deep intravenous sedation for penile plication surgery: patient tolerability and outcomes (AUA 2025) - "The anesthetic options evaluated included LA with oral sedation (methoxyflurane), NACS with midazolam and fentanyl, and DIS with midazolam, ketamine, propofol, and remifentanil. Penile plication is well tolerated when performed using LA with oral sedation, NACS, or DIS, with no significant differences in pain or complication rates between methods. All three anesthetic approaches are viable for outpatient penile plication, offering potential benefits such as reduced costs, minimized risks, and shorter wait times."

Clinical • Surgery • Anesthesia • Pain • Rheumatology

Inhaled methoxyflurane in patients with cancer: current applications and future directions. (PubMed, Curr Opin Support Palliat Care) - "IMF is a safe drug device combination that can reduce discomfort and improve treatment compliance with repeat procedures in cancer patients. Real-world studies should be performed to further evaluate its safety and quality of life in diverse cancer patient populations and guide patient selection."

Journal • Anesthesia • Mood Disorders • Oncology • Pain • Psychiatry

Methoxyflurane for Analgesia During Hysteroscopy (clinicaltrials.gov) - P=N/A | N=54 | Not yet recruiting | Sponsor: Dr. John A. Thiel Medical Professional Corporation

New trial • Anesthesia • Gynecology

Greenhouse gas impact from medical emissions of halogenated anaesthetic agents: a sales-based estimate. (PubMed, Lancet Planet Health) - "The global greenhouse gas impact from halogenated anaesthetic agents is falling due to lower use of desflurane in high-income countries. Efforts to reverse the increased use of desflurane in middle-income countries are needed. Replacing desflurane and isoflurane with sevoflurane constitutes an opportunity to markedly reduce the greenhouse gas impact from halogenated anaesthetic agents."

Journal • Anesthesia

Inhaled methoxyflurane (Penthrox) use in the outpatient and ambulatory setting: a systematic review. (PubMed, BMJ Open) - "Penthrox (methoxyflurane) shows promise as an analgesic for invasive, elective interventional procedures in the outpatient setting, although the relative benefits appear to vary depending on intervention and comparator pain control measures. There is a pressing need for robustly conducted, large, generalisable multicentre RCTs to evaluate the effectiveness of Penthrox."

Journal • Review • Anesthesia • Gastroenterology • Gynecology • Hematological Disorders • Musculoskeletal Diseases • Orthopedics • Pain • Urology

Study of the Use of Methoxyflurane Vs Placebo in the Management of Pain in Oral and Dental Emergencies in Adults: METODO (METhoxyflurane in ODOntology) (clinicaltrials.gov) - P3 | N=192 | Recruiting | Sponsor: University Hospital, Brest | Not yet recruiting ➔ Recruiting | Trial completion date: Aug 2025 ➔ Oct 2026 | Trial primary completion date: Jan 2025 ➔ Oct 2026

Enrollment open • Trial completion date • Trial primary completion date • Pain

Effectiveness of Penthrox vs Placebo in Sinus Procedures, a Clinical Trial (clinicaltrials.gov) - P1/2 | N=100 | Recruiting | Sponsor: St. Paul's Hospital, Canada

New P1/2 trial • Otorhinolaryngology • Pain • Respiratory Diseases • Sinusitis

Methoxyflurane in early analgesic therapy by ski patrol members on Swiss ski slopes - an observational cohort study. (PubMed, Scand J Trauma Resusc Emerg Med) - "The administration of methoxyflurane by trained ski patrol members is a safe and effective option for early pain management in ski slope injuries. Methoxyflurane could thus represent a useful bridging measure, enabling the ski patrol to relieve moderate to severe pain until professional rescue services arrive. However, it does not seem ideal for lower leg injuries."

Journal • Observational data • Retrospective data • Pain

Inhaled methoxyflurane (Penthrox®) as a novel pain relief for outpatient hysteroscopy and other gynaecological procedures. (ESGE 2024) - "No adverse events occurred but 88 (72%) women reported mild, self-limiting side effects.Conclusions Penthrox® appears safe, feasible and acceptable as a pain relief option during outpatient hysteroscopy and other intrauterine procedures. The effectiveness of Penthrox® should be evaluated against conventional pain control in an adequately powered multicentre randomised controlled trial."

Clinical • Anesthesia • Gynecology • Mood Disorders • Pain

Inhaled methoxyflurane (Penthrox®) use in the outpatient and ambulatory setting: a systematic review. (ESGE 2024) - "No serious adverse events were reported.Conclusions Penthrox® (methoxyflurane) shows promise as an analgesic for invasive, elective interventional procedures in the outpatient setting, although the relative benefits appear to vary according to the type of intervention and the comparator pain control measures. As planned and invasive procedures increase across medical specialities, there is a pressing need for robustly conducted, large, generalisable multicentre RCTs to evaluate the effectiveness of Penthrox® to reduce pain and enhance patient experience."

Clinical • Review • Anesthesia • Gastroenterology • Gynecology • Hematological Disorders • Mood Disorders • Musculoskeletal Diseases • Orthopedics • Pain • Psychiatry • Urology

The Role of GABA Receptors in Anesthesia and Sedation: An Updated Review. (PubMed, CNS Drugs) - "Ketamine, nitrous oxide, and xenon are not GABAR agonists and instead inhibit glutamate receptors-mainly NMDA receptors...Isoflurane and sevoflurane might have slightly different binding sites providing unexpected degree of selectivity...Penthrox (Galen, UK) is the special device designed for its administration...Remimazolam, a modified midazolam and methoxycarbonyl-etomidate (MOC-etomidate), an ultrashort-acting etomidate analog are two such examples...Carboetomidate is another soft analog of etomidate with low affinity for 11β-hydroxylase and is, therefore, unlikely to have clinically significant adrenocortical suppressant effects. Alphaxalone, a GABAAR agonist, is recently formulated in combination with 7-sulfobutylether-β-cyclodextrin (SBECD), which has a low hypersensitivity profile."

Journal • Review • Anesthesia • Cardiovascular • CNS Disorders • Depression • Immunology • Pain • Psychiatry

Face the facts: the green whistle is a hit! A review of consecutive emergency department use of methoxyflurane in children requiring wound care above the neck (EUSEM 2024) - "We seek forgiveness, not permission. We wish to present our experience and how we did it."

Clinical • Late-breaking abstract • Review • Anesthesia • Infectious Disease • Musculoskeletal Diseases • Novel Coronavirus Disease • Orthopedics • Pain • Pediatrics

How accurate is and how compliant are paediatric patients with the NHS11 advice given from clinically trained compared to non-clinically trained call-handlers? (EUSEM 2024) - "Introduction Any Emergency Department (ED) caring for children with facial wounds find that often the child and carer will not readily cooperate or remain a non moving target.The lack of on-site specialists (plastic, maxillofacial and 24/7 paediatric anaesthesia), presents significant challenges.Cases requiring emergent management result in transfer, delay or consent to ED treatment.Throughout Europe (& UK), Methoxyflurane (3ml inhaled) is licensed for relieving adult traumatic pain...We seek forgiveness, not permission. We wish to present our experience and how we did it."

Clinical • Anesthesia • Infectious Disease • Musculoskeletal Diseases • Novel Coronavirus Disease • Orthopedics • Pain • Pediatrics

Inhaled Analgesia in Dermatologic Settings: A Comprehensive Overview of Methoxyflurane. (PubMed, Skin Therapy Lett) - "The first-line modalities for procedural analgesia during most dermatologic procedures are topical and injectable local anesthetics, such as lidocaine. The limited side effect profile, ease of patient self-administration, rapid onset and quick resolution of central nervous system effects following cessation makes methoxyflurane an ideal choice for analgesia during outpatient dermatologic procedures. This review provides an overview of the supporting evidence for methoxyflurane inhalers and clinical commentary on potential indications for methoxyflurane use in dermatology."

Journal • Review • Aesthetic Medicine • Allergy • Anesthesia • Dermatology • Immunology • Mood Disorders • Pain

Inhaled analgesics for the treatment of prehospital acute pain-A systematic review. (PubMed, Acta Anaesthesiol Scand) - "We found low-quality evidence suggesting that both MF and N2O are safe and may have a role in the management of pain in the prehospital setting. There is low-quality evidence to support MF as a short-acting single analgesic or as a bridge to IV access and the administration of other analgesics. There may be occupational health issues regarding the prehospital use of N2O."

Journal • Review • Anesthesia • Critical care • Pain

Inhaled methoxyflurane (Penthrox®) as a novel pain relief for outpatient hysteroscopy and other gynaecological procedures. (PubMed, Eur J Obstet Gynecol Reprod Biol) - "Penthrox® appears safe, feasible and acceptable as a pain relief option during outpatient hysteroscopy and other intrauterine procedures. The effectiveness of Penthrox® should be evaluated against conventional pain control in an adequately powered multicentre randomised controlled trial."

Journal • Anesthesia • Gynecology • Mood Disorders • Pain

MAGPIE: Methoxyflurane Analgesia for Paediatric Injuries (clinicaltrials.gov) - P3 | N=192 | Completed | Sponsor: Medical Developments International Limited | Recruiting ➔ Completed

Trial completion • Pain • Pediatrics

Penthrox vs nitrous oxide for painful emergency medicine procedures (ANZCTR) - P3 | N=198 | Not yet recruiting | Sponsor: Eastern Health

New P3 trial • Pain

Managing acute pain with inhaled methoxyflurane in non-cancer patients: a review of the latest evidence. (PubMed, Curr Opin Support Palliat Care) - "Future use in remote medical interventions such as military contexts, in emergency room settings, and administration under the supervision of first responders such as non-paramedic and non-HCPs further broadens the scope of settings where IMF can meaningfully be implemented."

Journal • Review • Mood Disorders • Oncology • Pain • Psychiatry

The safety of methoxyflurane for emergency pain relief in children and adolescents: a retrospective cohort study. (PubMed, Prehosp Emerg Care) - "Compared with methoxyflurane treated patients, patients treated with an opioid analgesic were more likely to be hospitalized (aOR:1.23, 95%CI:1.09-1.39), while patients treated with no analgesic were less likely to be hospitalized (aOR:0.85, 95%CI:0.79-0.92). In children and adolescents transported by ambulance, the use of methoxyflurane was not associated with an increased risk of hospitalization, death, serious adverse drug reactions or liver and kidney toxicity."

Journal • Retrospective data • Pain • Pediatrics

Self-administered inhaled methoxyflurane (Penthrox®) as pre-injection analgesia in Podiatry Outpatients: A blinded, randomised study. (ANZCTR) - P4 | N=40 | Recruiting | Sponsor: Claire Huxtable | Not yet recruiting ➔ Recruiting

Enrollment open • Pain

Analgesic effectiveness of methoxyflurane inhaler during genicular nerve block in knee osteoarthritis: a randomized controlled trial. (PubMed, Reg Anesth Pain Med) - "A methoxyflurane inhaler combined with local anesthesia provided better procedural pain control than local anesthesia alone with no observable differences in adverse effects. Future studies evaluating the impact of a methoxyflurane inhaler on different types of painful procedures are warranted."

Journal • Anesthesia • Critical care • Immunology • Mood Disorders • Osteoarthritis • Pain • Psychiatry • Rheumatology

Synthesis and stability studies of CF2OMe-decorated aliphatic amines (ACS-Fall 2024) - "Since the discovery of methoxyflurane in 1960th, the trifluoromethoxy group has been unjustly neglected...On the other hand, the stability of the CF2OMe-group in common transformation and the impact of this fragment on the physicochemical properties compared to other fluorinated analogs will also be discussed. The set of primary investigated amines is depicted below."