How flupirtine works
Flupirtine has a threefold mechanism of action:
1) The analgesic effect comes from its action at the interfaces (synapses) of nerve cells that conduct the pain stimulus from the body to the brain. Electrical signals are transported via these pathways and reach the synapses, where they are transmitted to the next nerve cell with the help of neurotransmitters.
2) The muscle relaxing effect of flupirtine is based on a similar mechanism. Nerve impulses from the brain to the muscle are only transmitted in a weakened form. Because the active ingredient acts primarily on heavily used muscles, muscle tension is specifically relieved, but there is no general muscle relaxation (muscle relaxation).
Nerve cells become increasingly sensitive to persistent pain stimuli, i.e. their pain threshold decreases. Even a light touch can then be felt as pain. Flupirtine counteracts this mechanism by raising the threshold for stimulus transmission and thus restoring it to normal.
Absorption, degradation and excretion
Most of the active ingredient is excreted in the urine via the kidneys, and a smaller portion is also excreted in the stool via the bile. About seven to ten hours after ingestion, the blood level of flupirtine has dropped by half again.
When was flupirtine used?
How flupirtine was used
When taking Flupirtine hard capsules, the dosage is 100 milligrams of the active ingredient three to four times a day. In cases of severe pain, the single dose can be increased up to 200 milligrams (maximum total daily dose 600 milligrams).
Slow-release tablets containing 400 milligrams of flupirtine, which release their active ingredient slowly throughout the day, are taken only once a day.
What are the side effects of flupirtine?
In more than ten percent of patients, flupirtine causes an increase in certain enzyme levels in the blood (transaminases) and fatigue, especially at the beginning of treatment.
One in ten to one hundred people treated develops dizziness, heartburn, nausea, vomiting, stomach upset, constipation, diarrhea, bloating, increased sweating, sleep disturbances, loss of appetite, depression, tremor, headache, abdominal pain, dry mouth, and nervousness.
In individual cases, a harmless green coloration of the urine is possible.
Since flupirtine can cause severe liver damage, all approved preparations were withdrawn from the market in 2018.
What was to be considered when taking flupirtine?
Contraindications
Flupirtine should not be taken by:
- Known liver damage or liver dysfunction.
- Myasthenia gravis (inherited muscle disease)
- Alcohol abuse
- @ History or presence of tinnitus
Drug interactions
Flupirtine is transported in the blood via transport proteins (albumin), which also transport other drugs. When taken at the same time, flupirtine may therefore displace the other substances from the blood, making them more potent.
Studies suggest that this is the case with sedatives and sleeping pills from the benzodiazepine class (such as diazepam, lorazepam, lormetazepam) and coumarin-type anticoagulants (such as warfarin, phenprocoumon).
Age restriction
Flupirtine was not approved in children and adolescents under 18 years of age. Elderly patients and patients with renal or hepatic impairment were allowed to take only a reduced dose of flupirtine.
Pregnancy and Lactation
Because limited data on tolerability and safety are available for use during pregnancy and lactation, Flupirtine should not be taken during this time.
How to obtain medication with flupirtine
The Coordination Group for Mutual Recognition Procedures and Decentralized Procedures (CMDh) confirmed this recommendation. As a result, corresponding drugs were withdrawn from the market and have not been available since.
