Flupirtine

Flupirtine is an aminopyridine that functions as a centrally acting non-opioid analgesic that was originally used as an analgesic for acute and chronic pain but in 2013 due to issues with liver toxicity, the European Medicines Agency restricted its use to acute pain, for no more than two weeks, and only for people who cannot use other painkillers. In March 2018, marketing authorisations for flupirtine were withdrawn following a European Medicines Agency recommendation based on the finding that the restrictions introduced in 2013 had not been sufficiently followed in clinical practice, and cases of serious liver injury still occurred including liver failure.

Flupirtine is a selective neuronal potassium channel opener (SNEPCO) that also has NMDA receptor antagonist and GABA_A modulatory properties.

It first became available in Europe in 1984 under the brand name Katadolon and after it went off patent many generic brands were introduced.

Flupirtine is used as an analgesic for acute pain, in moderate-to-severe cases. Its muscle relaxant properties make it popular for back pain and other orthopaedic uses, but it is also used for migraines, in oncology, postoperative care, and gynaecology.

In 2013 due to issues with liver toxicity, the European Medicines Agency restricted its use to acute pain, for no more than two weeks, and only for people who cannot use other painkillers.

The most serious side effect is frequent hepatotoxicity which prompted regulatory agencies to issue several warnings and restrictions.

Flupirtine is devoid of negative psychological or motor function effects, or effects on reproductive function.

Although some studies have reported flupirtine has no addictive properties, there was suggestion that it may possess some abuse potential and liability. There were at least two registered cases of flupirtine abuse. Drug tolerance does not develop in most cases, but has individually occurred.