Thiocolchicoside Duration of Treatment
Thiocolchicoside should be administered for a maximum of 7 days when given orally, and should not exceed 5 days when administered by injection. 1
Regulatory Restrictions and Safety Concerns
- The European Medical Agency has imposed strict time limitations on thiocolchicoside use due to concerns about its metabolite M2, which may cause aneuploidy (abnormal chromosome numbers) 2
- Oral administration: maximum 7 consecutive days 1, 2
- Intramuscular injection: maximum 5 consecutive days 2, 3
- These restrictions apply regardless of the indication (acute low back pain, muscle spasm, or other musculoskeletal conditions) 2, 4
Clinical Evidence Supporting Short-Term Use
- A multicenter randomized controlled trial demonstrated that twice-daily administration of 4 mg thiocolchicoside for 5 days provided efficient and safe treatment for acute low back pain with muscle spasm 3
- Significant pain reduction was observed by day 3, with continued improvement through day 5 3
- A comparative study in Indian patients showed efficacy with 7 days of oral thiocolchicoside for low back pain associated with muscle spasm 4
- The combination of thiocolchicoside (4 mg) with aceclofenac showed statistically significant reduction in pain severity and muscle spasm when administered twice daily for 7 days 5
Important Safety Considerations
- Pregnancy contraindication: Thiocolchicoside should not be used during pregnancy due to potential harm to the developing fetus 2
- Male fertility concerns: The drug has been associated with infertility in men 2
- Thiocolchicoside is generally well-tolerated with minimal adverse effects compared to other muscle relaxants like tizanidine, which causes more sedation, drowsiness, and dizziness 4
- No patients were withdrawn due to adverse effects in the 5-day trial 3
Practical Treatment Algorithm
For acute muscle spasms or low back pain:
- Days 1-5: Thiocolchicoside 4 mg intramuscularly twice daily (if injectable route chosen) 3
- Days 1-7: Thiocolchicoside 4 mg orally twice daily (if oral route chosen) 4, 5
- Reassess at day 3: Significant improvement should be evident; if no response, consider alternative diagnosis or treatment 3
- Maximum duration: Do not exceed 7 days oral or 5 days injectable under any circumstances 2
Common Pitfalls to Avoid
- Never extend treatment beyond the recommended duration even if symptoms persist, as the risk of chromosomal abnormalities increases with prolonged use 2
- Do not use thiocolchicoside as maintenance therapy for chronic conditions 2
- If symptoms require treatment beyond 7 days, switch to alternative muscle relaxants with better safety profiles for longer-term use, such as baclofen (which can be used for extended periods) 1
- Always combine with appropriate analgesics (NSAIDs or paracetamol) rather than using thiocolchicoside as monotherapy 4, 5