A fixed-dose combination (FDC) analgesic, antipyretic, and centrally-acting muscle relaxant. Aceclofenac is a potent NSAID with preferential COX-2 inhibition, Paracetamol is a centrally-acting analgesic and antipyretic, and Chlorzoxazone is a centrally-acting skeletal muscle relaxant. This combination is widely used in India for the management of acute painful musculoskeletal conditions with associated muscle spasm, such as low back pain, cervical spondylosis, and post-traumatic pain. It provides synergistic action for pain relief, inflammation reduction, and muscle relaxation.
Adult: One tablet twice daily, after meals. Maximum: Two tablets in a day (i.e., Aceclofenac 200mg, Paracetamol 650mg, Chlorzoxazone 1000mg).
Note: To be taken orally with or immediately after food with a full glass of water to minimize GI upset. Do not crush or chew. The tablet should be swallowed whole. Do not lie down for at least 10 minutes after taking the dose.
The combination exerts a multi-modal action. Aceclofenac inhibits the cyclooxygenase (COX) enzymes, preferentially COX-2, thereby reducing the synthesis of prostaglandins (PGs) responsible for pain, inflammation, and fever at the peripheral site. Paracetamol's exact mechanism is not fully elucidated but is believed to act centrally by inhibiting prostaglandin synthesis in the CNS, possibly via COX-3 inhibition, and modulating the serotonergic and cannabinoid pathways, providing analgesic and antipyretic effects. Chlorzoxazone acts primarily at the level of the spinal cord and subcortical areas of the brain by inhibiting polysynaptic reflex arcs involved in producing and maintaining skeletal muscle spasm.
Pregnancy: Category C (Aceclofenac/Chlorzoxazone) and Category B (Paracetamol) as per US FDA. Avoid in first and second trimester unless potential benefit justifies risk. Contraindicated in third trimester due to risk of premature closure of ductus arteriosus, delayed labor, and maternal bleeding. Paracetamol is the preferred analgesic for short-term use.
Driving: May impair mental and/or physical abilities required for driving or operating machinery due to dizziness and drowsiness caused by Chlorzoxazone. Patients should be cautioned not to drive until they know how the medication affects them.
| Warfarin/Acenoocumarol | Increased risk of bleeding due to Aceclofenac's antiplatelet effect and displacement from protein binding. | Major |
| Other NSAIDs (e.g., Aspirin, Ibuprofen) | Increased risk of GI toxicity and reduced antiplatelet effect of aspirin. | Major |
| Methotrexate | Aceclofenac may decrease methotrexate clearance, increasing toxicity risk. | Major |
| Lithium | Aceclofenac may decrease renal lithium clearance, raising lithium levels and risk of toxicity. | Major |
| Diuretics (Furosemide, Thiazides) | Reduced diuretic and antihypertensive efficacy; increased risk of nephrotoxicity. | Moderate |
| ACE Inhibitors (Ramipril) / ARBs (Losartan) | Reduced antihypertensive effect; increased risk of renal impairment. | Moderate |
| Corticosteroids (Prednisolone) | Markedly increased risk of GI ulceration and bleeding. | Major |
| Selective Serotonin Reuptake Inhibitors (SSRIs e.g., Sertraline) | Increased risk of upper GI bleeding. | Moderate |
| Anticoagulants (Heparin, DOACs) | Increased bleeding risk. | Major |
| Antiepileptics (Phenobarbital, Carbamazepine, Phenytoin) | Increased metabolism of Paracetamol to toxic NAPQI, raising hepatotoxicity risk. | Moderate |
| Isoniazid | Increased risk of Paracetamol hepatotoxicity. | Moderate |
| Alcohol | Chronic use increases risk of Aceclofenac GI bleeding and Paracetamol hepatotoxicity. Potentiates CNS depression from Chlorzoxazone. | Major |
| CNS Depressants (Benzodiazepines, Opioids, Antihistamines) | Additive sedation, dizziness, and impaired motor skills with Chlorzoxazone. | Major |
Same composition (Aceclofenac (100mg) + Paracetamol (325mg) + Chlorzoxazone (500mg)), different brands: