Mephenesin (
INN
Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway. Before the advent of motorized transportation, they also provided accomm ...
), also called myanesin,
is a centrally acting
muscle relaxant
A muscle relaxant is a drug that affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasms, pain, and hyperreflexia. The term "muscle relaxant" is used to refer to two major therapeu ...
. It can be used as an
antidote
An antidote is a substance that can counteract a form of poisoning. The term ultimately derives from the Greek term φάρμακον ἀντίδοτον ''(pharmakon antidoton)'', "(medicine) given as a remedy". An older term in English which is ...
for
strychnine poisoning
Strychnine poisoning is poisoning induced by strychnine. It can be fatal to humans and other animals and can occur by inhalation, swallowing or absorption through eyes or mouth. It produces some of the most dramatic and painful symptoms of any kno ...
. Mephenesin however presents with the major drawbacks of having a short duration of action and a much greater effect on the spinal cord than the brain, resulting in pronounced respiratory depression at clinical doses and therefore a very low
therapeutic index
The therapeutic index (TI; also referred to as therapeutic ratio) is a quantitative measurement of the relative safety of a drug with regard to risk of overdose. It is a comparison of the amount of a therapeutic agent that causes toxicity to the ...
. It is especially dangerous and potentially fatal in combination with
alcohol
Alcohol may refer to:
Common uses
* Alcohol (chemistry), a class of compounds
* Ethanol, one of several alcohols, commonly known as alcohol in everyday life
** Alcohol (drug), intoxicant found in alcoholic beverages
** Alcoholic beverage, an alco ...
and other depressants. Mephenesin was the inspiration for the synthesis of a derivative of
1,3-propanediol,
meprobamate
Meprobamate—marketed as Miltown by Wallace Laboratories and Equanil by Wyeth, among others—is a carbamate derivative used as an anxiolytic drug. It was the best-selling minor tranquilizer for a time, but has largely been replaced by the benz ...
, by Bernard Ludwig and
Frank Berger, the first tranquilizer to see widespread clinical use. Mephenesin is no longer available in North America but is used in Italy and a few other countries. Its use has largely been replaced by the related drug
methocarbamol, which is better absorbed.
Mephenesin may be an
NMDA receptor antagonist
NMDA receptor antagonists are a class of drugs that work to receptor antagonist, antagonize, or inhibit the action of, the NMDA, ''N''-Methyl-D-aspartate receptor (NMDA receptor, NMDAR). They are commonly used as anesthetics for humans and anima ...
.
Mephenesin was previously used in France as an OTC muscle relaxant called Décontractyl but was taken out of production by Sanofi Aventis and due to a French Health Ministry decree in July 2019.
See also
*
Carisoprodol
Carisoprodol, sold under the brand name Soma among others, is an oral medication used for musculoskeletal pain. Effects generally begin within half an hour and last for up to six hours.
Common side effects include headache, dizziness, and s ...
*
Chlorphenesin
*
Guaifenesin
Guaifenesin, also known as glyceryl guaiacolate, sold under the brand name Mucinex, among others, is an expectorant medication taken by mouth and marketed as an aid to eliminate sputum from the respiratory tract. Chemically, it is an ether of ...
*
Mephenoxalone
*
Methocarbamol
*
Prenderol
External links
*
*
References
Diols
Drugs with unknown mechanisms of action
Muscle relaxants
Phenol ethers
{{musculoskeletal-drug-stub