['low back pain']
['sirdalud® 2 mg tablets administered']

        Inclusion Criteria:

          1. Age between 18 and 65 years old

          2. Average low back pain intensity moderate to severe (≥ 60 mm in the VAS) at Visit 1

          3. Positivity to Schober test (i.e. measure < 5 cm) at Visit 1

          4. Acute low back pain started at least 24 hours prior to inclusion in the trial and more
             than 6 weeks after the last episode of acute low back pain

          5. Negative pregnancy test for women of childbearing potential (to be performed at Visit
             1) and use of an acceptable mean of contraception (condom or mechanical methods) in
             the previous 2 months and for whole duration of the study

          6. Signed Informed Consent

        Exclusion Criteria:

          1. History of chronic low back pain

          2. Current treatment with drugs having significant effects at the alpha2 receptors
             whether agonist (i.e., clonidine, methyldopa) or antagonist (i.e., phenothiazines,
             imipramine)

          3. Current treatment with any other muscle relaxant or any drugs having muscle relaxant
             properties

          4. Known allergies, hypersensitivity, or intolerance to tizanidine or paracetamol or any
             excipients used in their manufacture (included patients with known rare hereditary
             problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose
             malabsorption)

          5. Signs of nasal congestion, nasal polyps, mucosal lesions of the nostrils, postnasal
             drip of any etiology or any clinically significant nasal pathology that may affect the
             absorption of study medication or the assessment of safety

          6. Evidence of clinically unstable disease, as determined by medical history, physical
             examination, that, in the Investigator's opinion, preclude entry into the study

          7. Spinal surgery within 1 year of study entry

          8. Evidence of clinical gastrointestinal malabsorption

          9. Use of steroids within 3 months of study entry or any other long-term treatment with
             steroids

         10. Use of NSAID's or other anti-inflammatory drugs 6 hours prior to study inclusion

         11. Use of fluvoxamine or ciprofloxacin, or other inhibitors of CYP1A2 such as
             antiarrhythmics (amiodarone, mexiletine, propafenone), cimetidine, fluoroquinolones
             (enoxacin, pefloxacin, norfloxacin), rofecoxib, oral contraceptives, and ticlopidine

         12. Use of hypnotics or other CNS depressants

         13. Blood pressure <100/70 mmHg

         14. History of lumbar spinal stenosis, fibromyalgia, or ankylosing spondylitis

         15. Severe scoliosis

         16. More severe pain in a region other than the lower back

         17. Acute low back pain associated with chills or fever

         18. Pregnancy, breast feeding

         19. Treatment with another investigational agent within the last 30 days

         20. Known or suspected history of alcohol or drug abuse based on medical history, physical
             examination, or the Investigator's clinical judgment
      