A Milestone Moment: FDA Approves Addyi® for Hypoactive Sexual Desire Disorder in Postmenopausal Women
December 17, 2025
Free CME credits
Both our subscription plans include Free CME/CPD AMA PRA Category 1 credits.
Brand Name :
Penthrox
Synonyms :
methoxyflurane
Class :
General anesthetics/ inhalation anesthetics
Brand Name :
Penthrox
Synonyms :
methoxyflurane
Class :
General anesthetics/ inhalation anesthetics
Dosage Forms & Strengths
Inhalation
3ml bottle
The contents of the bottle must be inhaled using the inhaler device as needed.
When finished, a third 3 ml dose might be given if more analgesia is needed.
6 milliliters is the maximum total dose per treatment session.
It is advised to refrain from administering medication on consecutive days. The weekly total dosage shouldn't be more than 15ml
indications: it is indicated in the treatment of moderate to severe pain
Not recommended for use in the pediatric population
Refer to adult dosing
the serum levels of methoxyflurane may be increased
the rate of metabolism of methoxyflurane may be increased
the rate of metabolism of abiraterone may be decreased
the rate of metabolism of abrocitinib may be reduced
the rate of metabolism of abiraterone may be decreased
the risk of hypertension may be increased
the risk of hypertension may be increased
the rate of metabolism of acenocoumarol may be reduced
the hepatotoxic activity of acetaminophen may be increased
the risk of CNS depression may be increased
the rate of metabolism of methoxyflurane may be decreased
the antihypertensive activity of aliskiren may be reduced
the cardio depressant activity of methoxyflurane may be increased
the rate of metabolism of methoxyflurane may be decreased
the rate of metabolism of methoxyflurane may be increased
the risk of hypertension may be increased
the antihypertensive activity of atenolol may be reduced
the risk of hypertension may be increased
the risk of CNS depression may be increased
Actions and spectrum:
Methoxyflurane affects the body in a few key ways. First, it slows down the transfer of ions and molecules between cells. It does this by reducing the time gap junction channels stay open and increasing the time they stay closed. Second, methoxyflurane makes lipid membranes more fluid. This increased fluidity helps activate calcium-dependent ATPase within the sarcoplasmic reticulum. Third, methoxyflurane interacts with various cellular receptors and channels. These include NADH dehydrogenase, ATP synthase D subunits, glutamate receptor, glycine receptor, large conductance Ca2+ activated potassium channel, and GABA receptor. By interacting with these receptors and channels, methoxyflurane influences synaptic transmission and ion channel activity.
Frequency not defined
Agitation
Amnesia
Blurred vision
Choking
Cough
Diplopia
Drowsiness
Dysarthria
Euphoria
Fatigue
Headache
Hypotension
Hypoxia
Jaundice
Liver damage
Nausea
Oral discomfort
Paraesthesia
Renal failure
Somnolence
Hyperhidrosis
Dysgeusia
Black Box Warning
Do not operate machinery or drive vehicles
Contraindication/Caution:
Contraindication:
Impaired consciousness
Predisposition to malignant hyperthermia
Respiratory depression
Previous episodes of malignant hyperpyrexia
Severe renal impairment
Pregnancy consideration:
To be used with caution in pregnancy
Lactation:
To be used with caution in lactating mothers as the data about the excretion of methoxyflurane into breast milk is not known
Pregnancy category:
Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester.
<b>Category B: There was a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.
Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.
Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.
Category X: Drugs listed in this category outweigh the risks over benefits. Hence, these categories of drugs need to be avoided by pregnant women.
Category N: There is no data available for the drug under this category
Pharmacology:
Methoxyflurane is a gas people breathe to make them sleep during surgery. It works fast to take away pain. This gas helps doctors control how deeply someone is asleep. Methoxyflurane leaves the body quickly after the surgery. That makes it easier for people to wake up.
Pharmacodynamics:
Methoxyflurane, an anesthetic, causes anesthesia. It changes how tissues act. This relaxes muscles and reduces pain. Methoxyflurane affects channels that make action potentials. It also reduces cell-to-cell connections through gap junctions.
Pharmacokinetics:
Absorption:
Methoxyflurane enters the body through inhalation. It quickly begins working as it turns into vapor in the lungs.
Distribution:
Methoxyflurane spreads easily into fatty tissues because it is lipophilic, meaning it dissolves well in oils and fats.
Metabolism:
The liver is the main place where methoxyflurane is broken down. Enzymes like CYP450 help with this by removing the methyl group (O-demethylation) and chlorine atoms (dichlorination). This creates byproducts such as oxalic acid and dichloroacetic acid.
Elimination:
When methoxyflurane leaves the body, about 60% exits through urine as organic fluorine and oxalic acid. The rest is breathed out unchanged or as carbon dioxide.
Administration:
The instructions for using methoxyflurane are very important. People should follow them exactly. They need to adjust how much they take based on their pain level. Taking it in bursts may help the pain relief last longer, around 25-30 minutes, compared to breathing it in steadily. Using the inhaler with the activated carbon part reduces risks of being exposed too much. The right way to use methoxyflurane is key.
Patient information leaflet
Generic Name: methoxyflurane
Why do we use methoxyflurane?
When you inhale methoxyflurane, it makes you feel sleepy. But doctors don’t use it much for surgery or childbirth these days. If they do use it, they mix it with nitrous oxide. This gives a mild anesthetic effect. Doctors also give medicine to relax your muscles during the procedure. The medicine makes your muscles very relaxed and loose.
Both our subscription plans include Free CME/CPD AMA PRA Category 1 credits.
On course completion, you will receive a full-sized presentation quality digital certificate.
A dynamic medical simulation platform designed to train healthcare professionals and students to effectively run code situations through an immersive hands-on experience in a live, interactive 3D environment.
When you have your licenses, certificates and CMEs in one place, it's easier to track your career growth. You can easily share these with hospitals as well, using your medtigo app.
