Muscle relaxants of central and peripheral action

In recent years, in clinical practice, widespread use of muscle relaxants of central action. Due to the fact that, in contrast to peripheral action relaxants, they do not disable spontaneous breathing, nor do they adversely affect the cardiovascular system and other vital organs and systems.

For the first time the study of central muscle relaxants was started in 1946 by Benjern Bradley. However, most of these drugs have sedative properties, and sedatives that eliminate anxiety and fear, such as sibazone, have a central muscle relaxant effect. Precisely the mechanism of central muscle relaxant action is not known, although drugs of this type oppress the spinal polysynaptic reflexes and disrupt their supraspinal regulation. Some drugs also affect the reticular neuronal mechanisms that control muscle tone.

Mureluxamts of central action

A drug	Single dose, g (tablets)
Benzodiazepines (sibazone, diazepam)	0.005-0.02
Isoprotane (carisoprodol)	0.25-0.35
Chloroxoxazone (parafon)	0.25-0.5
Metocarbamol (Roboxin)	0.25-0.5
Metaxalone (Relaxin)	0.8
Baclofen (lioresal)	0.01-0.03

Practically, the researchers managed to establish that myocaine - a representative of central muscle relaxants - causes a decrease in electrical excitability of skeletal muscles within 30 minutes after administration. It also has a mild analgesic and sedative effect. Miorelaxation is not accompanied by unpleasant sensations, therefore the drug was widely used in clinical practice. In many countries, this drug is known under various names: myocaine (Austria), Mi-301 (Germany) and GGT-forte - also Germany. In 1962, F. Yu. Rachinsky and O. M. Lerner developed an identical drug - miocene (mefedol). There are more than 50 different names for mephedol.

For clinical use, it is recommended that intravenous mefedol is administered intravenously in the form of a 10% solution of 5% glucose in 20 ml at one time or as a 20% solution of 10 ml in ampoules. In case of insufficient relaxation of the striated musculature, the dose can be increased to 40 ml of the solution. The duration of the initial dose is 25-35 minutes. After this, if necessary, a maintenance dose of 1-2 g (10-20 ml of 10% solution of mephedol) is administered. If a precipitate precipitates in the ampoule, it is recommended that it be heated in warm water, after which the sediment disappears. Accepted inside mefedol does not have an effect.

Absolute contraindications to the use of mephedol in clinical practice is not established due to the low toxicity of the drug and the lack of cumulation. It is not recommended to use the drug in severe cardiovascular diseases, accompanied by severe hypotension. Very rarely there is light dizziness, a feeling of a rush of blood to the head. These sensations can be avoided by injecting the drug slowly. Mefedol approved by the Pharmacological Committee of the Ministry of Health in 1966 and for chemical and pharmacological properties is identical to the above drugs used abroad.

The test of the action of mefedal on the motor function of the uterus was first carried out on pregnant and nonpregnant rabbits VA Strukov and LB Eleshina (1968). It is established that mefedol does not reduce the tone of the pregnant uterus and does not alter its contractile activity. Against the background of mefedol, uterotonic drugs (pituitrin, oxytocin, pachycarpine, etc.) have their usual effect.

When using mephedol in the clinic, it is revealed that the drug weakens the feeling of fear, mental stress, suppresses negative emotions, thus ensuring a calm behavior of the pregnant woman and the mother in childbirth. In addition, in the vast majority of cases when the drug is administered, there is a marked decrease in the response to pain stimuli. This is probably due to the fact that, like other muscle relaxants of the central action, mefedol due to the dual nature of the action refers to two groups of substances - muscle relaxants and tranquilizers.

Mefedol when administered at a dose of 1 g does not adversely affect the fetus and the newborn, due to poor penetration through the placenta. It is shown that mefedol in a dose of 20 ml of a 10% solution administered intravenously does not worsen the conditions of hemostasis in women in labor. Therefore, mefedol can be used in labor to relax the muscles of the pelvic floor and prevent birth trauma. This is important, as modern research (WHO) shows that the side effects of episiotomy (pain, sexual problems) can be more significant when cutting the perineum than with a natural rupture.

Clinical and experimental studies have shown that mefedol is an effective treatment for chills, due to the hypothermic effect (after cavitary operations, blood transfusions). A method for the use of mephedol has been developed - at the end of the period of unfolding in the miscarriages or at the beginning of the period of exile in the primiparas, ie 30-45 min before the birth of the child, a 10% solution of the central muscle relaxant, mephedol (1000 mg) glucose solution (500 mg). Mefedol has a selective relaxing effect on the muscles of the perineum and pelvic floor. The drug contributes to the prevention of gaps in the perineum - the frequency of its damage with the use of the drug is 3 times less than in the control group. With preterm labor with the use of mephedol, it was possible to avoid the perineal incision (surgical trauma) altogether, and also to prevent the head injury of the premature fetus due to the relaxing effect of mephedol on the muscles of the perineum and pelvic floor. Thus, the use of mefedol reduces the birth trauma of the mother, contributes to the prevention of fetal and newborn injuries in normal and complicated childbirth.

[1], [2], [3], [4], [5], [6], [7], [8]