To evaluate efficacy of Finalgon® cream (1.08% Nicoboxil/ 0.17% Nonivamide) versus placebo in patients with acute low back pain. To investigate the safety and tolerability of repeated use of Finalgon® cream (1.08% Nicoboxil/ 0.17% Nonivamide).

Inclusion criteria:

1. Patients must sign and date an Informed Consent consistent with International Conference on Harmonisation (ICH)/Good Clinical Practice (GCP) guidelines and local regulation prior to participation in the trial.
2. Patients must agree to cooperate with all trial evaluations and perform all required tasks.
3. Patients must have acute nonspecific low back pain, ICD-10 code: M54.5.
4. Patients must have acute low back pain for more than 2 days and less than 21 days (= 3 weeks).
5. Male or female more or equal 18 and less or equal 65 years of age at Visit 1(Baseline).
6. Low back pain Pain intensity more or equal 5 on a 0-10 numerical rating scale (NRS).

Exclusion criteria:

1. Patients with a significant disease other than acute nonspecific low back pain. A significant disease is defined as a disease which, in the opinion of the investigator, may (i) put the patient at risk because of participation in the trial, or (ii) influence the results of the trial, or (iii) cause concern regarding the patient's ability to participate in the trial.
2. Multilocular pain or panalgesia.
3. History of more than 3 low back pain episodes in the last 6 months.
4. Acute low back pain due to vertebral collapse or neoplastic, inflammatory (ankylosing spondylitis), traumatic, or infective origins.
5. Abnormal findings in at least one of the following assessments: Achilles tendon reflex, patella reflex, heel walking, toe walking, cutaneous sensitivity of the legs (including gluteal region), paresis tests in supine position upon dorsiflexion, plantarflexion, hip flexion, knee extension.
6. Neurogenic Bladder and/or rectum dysfunction.
7. Any condition, disease or concomitant treatment that in the judgement of the investigator will affect the patient's ability to participate in the clinical trial or which will influence the trial methodology used.
8. Negative experience in the past with heat treatment for muscle complaints (e. g. hot water bottle, heat pads, hyperemisation-inducing topical creams, ointments or patches).
9. Patients with history of treatment of back pain with centrally acting drugs (e.g. opioids) and muscle relaxants within 6 months prior to enrolment.
10. Surgery due to back pain or rehabilitation due to back pain in the last 12 months.
11. Spinal injection back pain treatment within 6 months prior to enrolment.
12. Intake of antidepressant/antipsychotic medication within 4 weeks prior to enrolment.
13. Treatment of the recent low back pain period with oral analgesics for more than 4 consecutive days.
14. Locally applied medication to the back within 24 hours prior to enrolment (topical treatments, injections).
15. Non-pharmacological low back pain treatment (physiotherapy, heat treatment [e.g. hot water bottle, heat patch], or massages) within 12 hours prior to enrolment.
16. Administration of other analgesics within 12 h prior to enrolment (exception: acetylsalicylic acid [ASS] up to 100 mg/daily for anti-platelet-aggregation therapy).
17. Non-pharmacological low back pain treatment (physiotherapy, heat treatment [e.g. hot water bottle, heat patch], or massages) within 12 hours prior to enrolment.
18. Participation in an investigational drug or device trial within 4 weeks prior to enrolment.
19. History of treatment of back pain with centrally acting drugs (e.g. opioids) and muscle relaxants.
20. Treatment of the recent low back pain period with oral analgesics for more than 4 consecutive days.
21. Surgery due to back pain or rehabilitation due to back pain in the last 12 months.
22. Spinal injection back pain treatment within 6 months prior to enrolment.
23. Intake of antidepressant/antipsychotic medication within 4 weeks prior to enrolment.
24. Known hypersensitivity to nicoboxil, nonivamide, or other ingredients of the cream.
25. Known hypersensitivity to paracetamol.
26. Skin lesions (e.g. rash, bruising, laceration) in the back region.
27. Known history of central nervous system diseases with severe intellectual and memory disorders, psychiatric disorders.
28. History of abuse of alcohol/drugs within six months prior to enrolment.
29. Acute and relapsed chronic kidney diseases.
30. Severe hepatocellular insufficiency.
31. Pregnant or nursing women, including female patients with positive ß-HCG test at Visit 1.
32. Female patients of child-bearing potential not using highly effective method of birth control.
33. Patients who are currently participating in another trial or who have been participating in another trial within one month prior to Visit 1, and patients who have previously been randomised in this trial.

Treated set (TS): All randomised patients who used at least one dose of study medication were included in the treated set.

Adverse Event's collected after the first dose and upto the residual effect period (REP) period after the last drug administration (from first study administration until 24 hours after last study administration) ie. up to 5 days.