1. Clinical Overview
Aceclofenac (100mg) + Thiocolchicoside (4mg) is a widely prescribed, fixed-dose combination (FDC) analgesic and muscle relaxant in India. It is primarily indicated for the management of painful musculoskeletal conditions, particularly those associated with muscle spasm and inflammation, such as low back pain, cervical spondylosis, and post-operative orthopedic pain. Aceclofenac is a potent non-steroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class, providing anti-inflammatory, analgesic, and antipyretic effects. Thiocolchicoside is a semi-synthetic derivative of colchicine with potent muscle relaxant properties, acting centrally at the spinal cord and brain stem levels. This combination offers synergistic action by targeting both the inflammatory pain pathway and the muscular spasm component, providing comprehensive relief in conditions where pain and spasm coexist. It is considered a rational FDC as per Indian clinical practice guidelines for specific musculoskeletal disorders.
| Onset | Duration | Bioavailability |
|---|---|---|
| Analgesic effect typically begins within 30-60 minutes after oral administration. | Approximately 8-12 hours, supporting a twice-daily dosing regimen. | Aceclofenac: >90%; Thiocolchicoside: Approximately 60-70%. |
2. Mechanism of Action
The combination exerts a dual mechanism: Aceclofenac inhibits the cyclooxygenase (COX) enzymes, preferentially COX-2, thereby reducing the synthesis of prostaglandins (PGs), which are key mediators of pain, inflammation, and fever. Thiocolchicoside acts as a competitive antagonist at the strychnine-sensitive glycine and GABA-A receptors in the spinal cord and brain stem. This blockade reduces the activity of motor neurons, leading to muscle relaxation and relief of spasm. The combined effect provides superior relief in painful muscle spasms compared to either drug alone.
3. Indications & Uses
- Acute low back pain associated with muscle spasm
- Cervical spondylosis with radiculopathy/myofascial pain
- Post-traumatic musculoskeletal pain (e.g., sprains, strains)
- Post-operative orthopedic pain (e.g., after joint surgery, spinal procedures)
4. Dosage & Administration
Adult Dosage: One tablet (Aceclofenac 100mg + Thiocolchicoside 4mg) twice daily, preferably after meals.
Administration: Should be taken with or immediately after food to minimize gastric irritation. Tablet should be swallowed whole with a full glass of water. Do not crush or chew. Treatment should be for the shortest possible duration, typically not exceeding 7-10 days for acute conditions unless specifically advised by a physician.
5. Side Effects
Common side effects may include:
- Dyspepsia (indigestion)
- Nausea
- Abdominal pain
- Diarrhea or constipation
- Headache
- Dizziness
- Drowsiness/sedation (due to thiocolchicoside)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Anticoagulants (Warfarin, Acenocoumarol) | Increased risk of bleeding due to antiplatelet effect of aceclofenac and displacement from protein binding. | Major |
| Anti-platelets (Aspirin, Clopidogrel) | Additive risk of GI bleeding. | Major |
| Other NSAIDs (Ibuprofen, Diclofenac) | Increased risk of GI and renal toxicity without added benefit. | Major |
| Corticosteroids (Prednisolone) | Markedly increased risk of GI ulceration and bleeding. | Major |
| ACE Inhibitors (Ramipril, Enalapril) | Reduced antihypertensive effect; increased risk of renal impairment. | Moderate |
| Diuretics (Furosemide, Hydrochlorothiazide) | Reduced diuretic and antihypertensive efficacy; risk of renal failure. | Moderate |
| Lithium | Aceclofenac can decrease renal clearance of lithium, leading to toxicity. | Major |
| Methotrexate | May decrease methotrexate clearance, increasing risk of bone marrow toxicity. | Major |
| Selective Serotonin Reuptake Inhibitors (SSRIs e.g., Sertraline) | Increased risk of upper GI bleeding. | Moderate |
| Antidiabetic drugs (Sulfonylureas) | Potential for hypoglycemia; monitor blood glucose. | Moderate |
| CNS Depressants (Alcohol, Benzodiazepines, Opioids) | Additive sedative effect with thiocolchicoside, impairing alertness. | Moderate |
7. Patient Counselling
- DO take the tablet with or after food.
- DO inform your doctor about all other medicines you are taking, including over-the-counter pills, vitamins, and herbal supplements.
- DO report any history of asthma, stomach ulcers, kidney, liver, or heart problems.
- DO use the medicine for the shortest duration prescribed.
- DO NOT take a double dose to make up for a missed dose.
- DO NOT consume alcohol while on this medication.
- DO NOT give this medicine to children.
- DO NOT use it for fever or flu-like symptoms unless specifically advised.
8. Toxicology & Storage
Overdose: Aceclofenac Overdose: Nausea, vomiting, epigastric pain, GI bleeding, dizziness, tinnitus, headache, confusion, lethargy, acute kidney injury, metabolic acidosis, seizures, coma, respiratory depression. Thiocolchicoside Overdose: Enhanced CNS depression (profound drowsiness, ataxia, respiratory depression), muscle weakness, diarrhea (colchicine-like effect in high doses).
Storage: Store below 30°C, in a cool, dry place, protected from light and moisture. Keep the container tightly closed. Keep out of reach and sight of children. Do not use after the expiry date printed on the pack.