Paramedics Pathway Course – Methoxyflurane


Micro-lecture by the Australian Paramedical College

In this micro-lecture, Australian Paramedical College Hon. Snr. Lecturer Sam Willis discusses Methoxyflurane which is used to treat patients who present with acute or chronic pain.  Enrolled students have unlimited access to a rich library of learning materials such as this.


Let’s talk a little bit about  (Methoxyflurane) Penthrox. You may know this also to be called methoxyflurane. Now, when you guys get to the clinical workshops, you will become familiar with Penthrox (Methoxyflurane) as you will be using it to treat patients who present with acute or chronic pain. Now, for those of you who have never heard of it, never seen it or don’t know anything about it, Penthrox is an anesthetic gas type drug. It comes from the very similar family, and it produces anesthesia in your patients at high doses.

As you can see on this image here, methoxyflurane, just remembering that every drug has at least three different names. On here, you can see at least two. You can see methoxyflurane, and you can see Penthrox. Either to these are okay. It doesn’t matter when you call it Penthrox or methoxyflurane. They both refer to exactly the same drug.

As you can see, this is the drug here in this vial, so it’s a three milliliter. Milliliters is the volume, so three milliliters of methoxyflurane. You’ve got the inhaler itself. Inside is a certain type of a wick that allows the drug to be converted into a special inhalation substance. Then, of course, you’ve got the activate carbon filter, which allows any methoxyflurane that’s evaporated into the environment to be filtered to try and keep those responders who are using it, safe.

The carbon filter is an addition to the device itself to try and protect the responders from inhaling the gas. In fact, what you’ll notice in most ambulance service guidelines is it tells the responders that they can only use this with their patients on two separate occasions within any shift for that exact reason.

Now, the dilution hole is designed to give the patients a much more concentrated dose if they feel they need it. Let’s go through together, how we use it. Number one, you recognize that the patient’s in pain. You can use methoxyflurane to not necessarily completely get rid of pain but to numb the pain and to reduce it to the lowest threshold possible. It’s, generally speaking, very safe if you keep it within a certain dosage in therapy, which we’re not going to cover in this lecture.

When you’ve identified that, you need to take the methoxyflurane, open the cap, do all the safety checks that you would do. Ask your crew mate, “What’s that?” Check your [inaudible 00:02:33] guidelines, indications, contraindications, make sure all the seal’s not damaged, all those usual routine things. Pour the drug into the top end of the inhaler. Get your patient in the most comfortable position and then ask him to intake nice, deep breaths.

Now, it takes about 6 to 10 strong inhalations before your patient can actually start to feel the effects of the drug and then, of course, you can tell the patients, put their finger over the top of the carbonated filter if they need stronger doses.

That’s just a micro lecture on methoxyflurane. I hope it’s been useful for you and please make sure you take at your simulated guidelines for the indications and the contraindications. If you’re looking to understand why the indications and contraindications are what they are, you can find plenty of information on the website.

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