Thiocolchicoside Injection and Capsule in Treatment of Acute Low Back Pain

Inclusion Criteria: * Diagnosis of acute low back pain of recent onset (less than 7 days) and defined by spontaneous pain intensity at rest more than or equal to 50mm of the visual analog scale. * Presence of lumbar muscular contracture Exclusion Criteria: * Acute low back pain due to vertebral collapse or neoplastic, inflammatory (ankylosing spondylitis), or infective origins * Patients with psychiatric or mental diseases, or unable to follow the requests of the protocol * Renal failure (serum creatinine \> 160 µmol/l or \> 1.80 mg/dl) and/or severe hepatic dysfunction (alanine aminotransferase and/or aspartate aminotransferase and/or total bilirubin \> 2 Upper normal limit). * Positive history of cerebro-vascular accidents or myocardial infarction in the six months prior the inclusion. * Severe heart failure. * Myopathy / myasthenia. * Patients treated during two days prior to inclusion with steroidal agents. * Known or suspected hypersensitivity to thiocolchicoside. * Known or suspected hypersensitivity to nonsteroidal anti-inflammatory drugs * History of active peptic ulcer or gastro intestinal bleeding. * History of nonsteroidal anti-inflammatory drugs induced allergic asthma. * Concomitant treatment with 2-agonists (i.e. clonidine). * Pregnant or breast feeding women. * Females of child bearing potential, not taking adequate contraception. * Patients with history of alcohol, drugs or narcotics abuse. * Previous inclusion in this study or in another study in the past 6 months.