Repeated use of pain relief puffer may damage liver

The case has implications for the way methoxyflurane – which is used for rapid short-term pain relief during brief, painful procedures – is prescribed, the researchers say.

Methoxyflurane is no longer used in general anaesthesia due to its toxic effects on the liver, but side effects are rare from the single-dose puffers carried by paramedics.

Doctors examined a 33-year-old woman who was admitted to the Royal Brisbane and Women’s Hospital with acute hepatitis, four weeks after beginning a series of treatments for varicose veins.

She had no history of alcohol abuse, no risk factors for viral hepatitis and no family history of hepatitis or liver disease, Dr Kacey O’Rourke, the treating medical registrar said.

However, during each of her three vein treatments, she was given methoxyflurane via an inhaler.

“It seems the exposure to methoxyflurane in our patient was the likely cause of acute hepatitis, and it may be that repeated exposure was a contributing factor,” Dr O’Rourke said.

“This observation has implications for the way methoxyflurane is prescribed, including its use for procedural analgesia in cases in which several procedures (and hence, repeated dosing) are required.”

The patient recovered and has been advised to avoid future exposure to methoxyflurane.

The Medical Journal of Australia is a publication of the Australian Medical Association.

The statements or opinions that are expressed in the MJA  reflect the views of the authors and do not represent the official policy of the AMA unless that is so stated.

CONTACT:                 Dr Paul Kubler             07 3636 8111

                               Clinical Pharmacologist, Royal Brisbane Hospital

PS: The authors of this manuscript are unavailable for interviews.