Baclofen was originally developed in the 1960s to treat epilepsy. It works well for spastic seizures. Since 2009 it has also been used to combat alcohol addiction.
What is Baclofen?
Baclofen - chemically C10H12ClNO2 - is one of the muscle relaxants. They release a pathologically increased muscle tension. The active ingredient binds to the GABA-B receptors and acts there as an antagonist. He uses the fact that his molecular structure is similar to that of these proteins.
Synthesized baclofen is an odorless, crystalline, white powder with very poor water solubility. The muscle relaxant can be made in two ways and is available in the drugs Lioresal®, Lebic® and various generic drugs.
In milder disease, it is given orally in tablet form (10 mg or 25 mg). However, if there is, for example, severe multiple sclerosis, the doctor gives the active ingredient into the spinal cord fluid (intrathecally). It is only used orally in children and adolescents under 18 years of age. Corresponding studies on intrathecal use in this group of patients do not exist to date. This dosage form is also dispensed with if the patient has restricted reflexes and slowed circulation of the cerebral and spinal fluid.
Pharmacological effect
The permanent transmission of nerve signals to other nerve cells and from there to muscle cells results in permanent muscle tension, which ultimately leads to muscle spasms. One possible cause of this overuse of the skeletal muscles is the lack of signal control by the brain and / or the spinal cord.
Baclofen uses its chemical structure, which is similar to gamma-aminobutyric acid (GABA), by blocking the transmission of nerve signals between the spinal cord nerve cells. In this way they cannot even get to the muscle. Due to its muscle relaxant effect, it also dampens the activity of the brain. Voluntary muscle activity is also impaired in patients taking baclofen.
Baclofen changes the liver enzyme levels in the blood so that test results can be falsified. It is therefore imperative that the patient inform the attending physician that he is being prescribed baclofen. If people with liver disease need to use the drug, their liver values must be checked regularly. Blood sugar levels should be checked more often in diabetics. Patients who have to take preparations with baclofen should refrain from driving a car or using tools and machines, because the active substance impairs the ability to react.
Medical application & use
Baclofen has been shown to be extremely effective in treating people with multiple sclerosis, spinal cord injuries, central nervous system disorders, polio (cerebral palsy), cerebrovascular disorders, and muscle spasms caused by incorrect signal transmission from the spinal cord and / or brain.
In multiple sclerosis patients who suffer from severe painful spasms, the doctor administers it intrathecally to avoid the severe side effects of oral administration: If taken orally, baclofen would have to be consumed in a very high dose, as the active ingredient would otherwise arrive in too low a concentration where it should do its job. Multiple sclerosis patients are placed in a spinal cord catheter with a computer-controlled pump that is used to permanently deliver baclofen to the body in a much lower dose than when administered orally. The pump depot can be refilled through the skin as required.
The active ingredient works on the reflex arcs of the spinal cord by imitating the antispasmodic effect of the GABA receptors on the Renshaw cells.
If baclofen is administered orally, it is ineffective after 4 hours at the latest. The body excretes it largely unchanged in the urine. As a clinical study from the 1990s shows, in alcohol-dependent people who also suffer from depression and / or anxiety disorders, as an antagonist of the GABA receptors, it apparently combats the craving that is so feared by substance addicts, i.e. the desire for the substance . It has the same high level of effectiveness as diazepam, for example - but without having such harmful side effects as this one. Further clinical studies and innovative imaging techniques support the effectiveness of baclofen in alcohol addicts.
In contrast to France, where the preparation has been approved for this application for several years, in Germany it can only be used as an off-label. Baclofen was also effective in treating depression and anxiety in animal studies.
Risks & side effects
Fatigue, sleepiness, drowsiness and nausea are very common with baclofen use. Depression, nightmares, and in the elderly also confusion, headache, tremors, unsteady gait, dizziness, sleep disorders, blurred vision and other visual disturbances, decreased heart function, low blood pressure, vomiting, diarrhea, constipation, strong urination, rashes, muscle weakness and sweating have been observed frequently .
The agent should not be used in cases of hypersensitivity to the active ingredient, severe kidney damage, Parkinson's disease, brain disease caused by injury and rheumatism. Baclofen should only be administered orally to pregnant women after a thorough risk-benefit assessment, as the active ingredient can pass into the placenta. It can also be found in the breast milk of breastfeeding women. Although baclofen has not yet harmed infants, the drug is best used in low doses, if at all.
Baclofen drugs are taken gradually before stopping to avoid negative effects such as confusion, delusions, seizures, and difficulty concentrating. Baclofen increases the effects of antihypertensive agents, other muscle relaxants, psychotropic drugs, pain relievers, and certain antidepressants. Simultaneous administration of agents containing dopamine can lead to delusions. To avoid unforeseen risks, it must not be taken with alcohol under any circumstances.
