Background and aims. To ascertain the efficacy and safety of tolperisone hydrochloride (100 mg) and lidocaine (2,5 mg)  trigger zone injections  in alleviating myofascial pain.
Methods.  Fifty patients with myofascial pain, mean age 41,67 years (SD 11,86) were included in the study. The intensity of pain was evaluated using the visual analogue scales and McGill pain questionnaire. Visualization of area in spasm and understanding the vascular environment of trigger zone was carried using ultrasonic imaging of target muscle. To evaluate hypotensive and sedative effects of tolperisone we used the orthostatic test, Schulte’s test and Munsterberg’s test.
Results. The analgesic effects and muscle relaxation of tolperisone become apparent by day 3 post-injection, and the muscle relaxation effect is reaching its maximum on day 10 post-injection. Cardiovascular function following administration of tolperisone was evaluated using the orthostatic test which revealed good orthostatic tolerance. Single injection of tolperisone possessing a central muscle relaxant activity has no sedative effect and does not influence patient response time. The ultrasound examination data demonstrated the improvement of blood circulation in the myofascial trigger zone. 
Conclusions. The myofascial trigger zone is a densely contracted band of muscle with ischemic and hypoxic that can be seen on ultrasound imaging. Clinical study in patients with myofascial pain has demonstrated a positive muscle relaxant and analgesic effect of tolperisone that resulted in restoration of peripheral circulation in the myofascial trigger zone confirmed by ultrasound examination. An important benefit of this drug product is the absence of sedative effect and arterial hypotension

A STUDY OF THE EFFECT OF TOLPERISONE TRIGGER ZONE INJECTIONS IN PATIENTS WITH CHRONIC MYOFASCIAL PAIN