Last reviewed 2026-04-22 · How we verify

Methoxyflurane, MEOF

Methoxyflurane is a volatile halogenated ether anesthetic that depresses the central nervous system to produce anesthesia and analgesia.

Methoxyflurane is a volatile halogenated ether anesthetic that depresses the central nervous system to produce anesthesia and analgesia. Used for Acute pain relief (trauma, musculoskeletal injury), Anxiety relief in acute settings.

At a glance

Mechanism of action

Methoxyflurane acts as a general anesthetic by enhancing inhibitory GABAergic neurotransmission and inhibiting excitatory glutamatergic signaling in the central nervous system. It was historically used for general anesthesia and analgesia but has been largely withdrawn from many markets due to nephrotoxicity concerns. In recent years, it has been reintroduced in some regions at sub-anesthetic doses for acute pain relief and anxiety.

Approved indications

• Acute pain relief (trauma, musculoskeletal injury)
• Anxiety relief in acute settings

Common side effects

• Dizziness
• Nausea
• Headache
• Nephrotoxicity (at high/prolonged exposure)

Key clinical trials

• PENTHROX™ in the Canadian Emergency Department (ED) (PHASE4)
• Low Dose Methoxyflurane for Pain Relief During Minor Out-patient Urologic Procedures (PHASE4)

Primary sources

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Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Methoxyflurane, MEOF CI brief — competitive landscape report
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• Sunnybrook Health Sciences Centre portfolio CI