Methoxyflurane

Question 1

What is the MOA of methoxyflurane?

Answer 1

Inhalational analgesic, MOA is not clear

Question 2

What is the indication for methoxyflurane?

Answer 2

Moderate to servere pain

Question 3

What are contraindcations and cautions for methoxyflurane/use in pregnancy?

Answer 3

1. Known severe allergy
2. Personal or family history of malignant hyperthermia
3. Unable to obey commands
4. Known renal impairment
5. has received methoxy in the last week (freq admin incr risk renal impairment)

Cautions:

• Age>75 esp in presence of illness, dehydration or infection
• Pre-eclampsia - renal impairment is likely and methoxy will worsen this
• Admin within a confined space

Use in pregnancy
May be administered but effect of causing drowsiness in baby should be discussed with LMA esp if known signs of foetal distress
Some LMA’s may prefer to use EtNox and provide their own, this is acceptable provided it is an A size tank and can be restrained

Question 4

What is the dosage for methoxyflurane?

Answer 4

Max of 2x3ml doses (6ml) for a patient aged >/= 12 years

Max of 3ml for a child less than 12 yrs

Question 5

What are common adverse effects of methoxyflurane?

Answer 5

Sedation
Light headedness
Nausea
Dislike of the taste/smell

Question 6

What is malignant hyperthermia?

Answer 6

A muscle metabolism disorder affecting approx 20 families in NZ, most in the manawatu, develop a life threatening state of hyperthermia when exposed to certain anasthetic agents like methoxy

Question 7

Should methoxy be used in cases of dialysis, kidney stones or renal colic

Answer 7

Yes. In case of dialysis kidneys are already muntered, renal colic or kidney stones are rarely associated with renal impairment.