Spasticity is increased muscular tension. It is nearly always accompanied by muscular weakness. The legs are very often affected, where the interaction of the muscles during movement is disturbed, and consequently walking is impaired.
If movement is more disturbed as a result of spasticity than of muscular weakness, antispasticity drugs can improve movement. The following are examples of drugs used for treating spasticity:
- Drugs for muscular relaxation with an effect on the CNS e.g. baclofen, tizanidine or memantine;
- Drugs for muscular relaxation which acts on the musculature e.g. dantrolene; and
- Drugs active in the CNS with a primary palliative effect and additional muscle-relaxant e.g. tetrazepam and diazepam.
All drugs with an anti-spasticity effects must be administered cautiously and with very careful attention to dosage, since an improvement in spasticity will make the muscular weakness more emphatic. In addition, it is often necessary to retain a certain degree of ‘residual’ spasticity, to make sure, for example, that standing is still possible.
Baclofen
Baclofen has proved very effective in the treatment of spasticity and therefore is very often prescribed. To a certain extent its effect tends to subdue and to calm and it has an especially favourable antispasticity effect. The daily dose is adapted to each patient’s individual requirements.
Tizanidine
Like baclofen, this drug is also used for anti-spasticity treatment.
Memantine
Memantine has a very complex action and the actual anti-spasticity effect is less pronounced than with baclofen and tizanidine. Contrary to the other anti-spasticity drugs its effect is often not palliative, but can increase the degree of arousal. In certain cases, the preferred treatment is a combination of memantine and baclofen or tizanidine.
Dantrolene
Dantrolene is a highly-effective muscle relaxant which acts directly on the muscles. Therefore it is always used either if the effect of baclofen is inadequate or the spasticity is especially pronounced.
Tetrazepam/Diazepam
These drugs belong to the so-called benzodiazepines and have a sedative and anxiety-calming effect, tending to evoke a state of equilibrium. They also have a strong muscle-relaxing effect. Tetrazepam, in particular, has a good muscle-relaxant effect and is less sedative than diazepam.
Long-term antispasticity treatment exclusively with benzodiazepines is not recommended, since habituation (where the body adjusts to the drug and its effects are lessened) is a problem often encountered with these drugs. Accordingly, these drugs should be taken only for a limited period. Use should cease gradually, by reducing the dose over a long period of time.