Methoxyflurane

Methoxyflurane is a halogenated volatile anaesthetic agent with potent analgesic effects at sub-anaesthetic doses. Methoxyflurane widely used as an open-circuit anaesthetic in small laboratory animals for several decades. Methoxyflurane has the risk of nephrotoxicity[1][2].

Methoxyflurane is delivered via a hand-held inhaler[3].

The developmental toxicity of trace, subanesthetic, and anesthetic exposure to Methoxyflurane is examined in Swiss/ICR mice. No adverse effects on reproduction or fetal development were demonstrated following exposure to trace (2 ppm) and subanesthetic (60 ppm) concentrations of Methoxyflurane for 4 hours daily on days 6 through 15 of pregnancy. Exposure to an anesthetic concentration (2000 ppm; 0.2%) for the same period resulted in decreased fetal weight, decreased ossification, and delayed renal maturation. Additionally, the incidence of minor skeletal anomalies was increased. It is concluded that gestational exposure of mice to trace of subanesthetic concentrations of Methoxyflurane does not result in reproductive loss or morphologic abnormalities in their offspring[4].

[1]. Occupational exposure to methoxyflurane administered for procedural sedation: an observational study of 40 exposures. Br J Anaesth. 2018 Jun;120(6):1435-1437. [2]. Porter KM, et al. The role of inhaled methoxyflurane in acute pain management. Open Access Emerg Med. 2018 Oct 18;10:149-164. [3]. Methoxyflurane nephrotoxicity. JAMA. 1971 Aug 16;217(7):958-9. [4]. Wharton RS, et al., Developmental toxicity of methoxyflurane in mice. Anesth Analg. 1980 Jun;59(6):421-5.