methoxyflurane [Penthrox]

Question 1

Classification

Penthrox

Answer 1

Inhaled fluorinated hydrocarbon volatile anesthetic

Question 2

INDICATIONs

Penthrox

Answer 2

[EMR]
- self-administered - moderate to severe pain associated with trauma

Question 3

CONTRAINDICATIONs

Penthrox

Answer 3

• Children <18 year
• NOT hemodynamically stable
• Inadaquate understanding/lack of cooperation
• DLOC
• hx sig. renal impairment
• hx liver dysfunction 2nd to previous halogenated anesthetic
• hx // genetic hx of malignant hyperthermia
• dx muscular dystrophy
• pregnancy, intended pregnancy, breast-feeding
• Current use of tetracycline (antibiotic)

Question 4

Dosage - Adult

Penthrox

Answer 4

[EMR]
- 3mL via inhaler

ensure patient exhales through carbon filter

repeat x 1 @20mins // MAX dose - 6mL

Question 5

Pharmacodynamics

Penthrox

Answer 5

• u/k but fast acting

Question 6

Pharmacokinetics

Penthrox

Answer 6

Onset - 1 to 3 mins
Duration - 1 hour
Elimination - metabolized by the liver and excreted by the lungs

Question 7

Warnings // Precautons

Penthrox

Answer 7

• Supratherapeutic doses have been shown to lead to serious irreversible nephrotoxicity (follow dosing limitations)
• Maximum daily dose of 6mL should be used in a single 48 hour perios
• A treatment of Penthrox should be limited to a total dose of 15mL over one week
• EMR//practitioner exposure MAX 3 dose = 9mL/day

Question 8

ADVERSE EFFECTs

Penthrox

Answer 8

• ALOC (drowsiness)
• cough
• discomfort - odour/taste
• hypotension & bradycardia (rare)
• nausea // vomiting
• susceptibility // suggestibility w/ decreased inhibition

Question 9

OVERDOSE

Penthrox

Answer 9

• irreversible nephrotoxicity