Diclofenac is a potent non-steroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class. It is a non-selective cyclooxygenase (COX) inhibitor, exhibiting strong anti-inflammatory, analgesic, and antipyretic properties. It is widely used in India for managing pain and inflammation in various musculoskeletal and arthritic conditions. The 100mg strength is typically used for sustained release formulations for once-daily dosing.
Adult: For SR/ER 100mg tablet: Usually ONE tablet once daily. For acute pain, the lowest effective dose for the shortest duration is recommended. Maximum daily dose: 150mg.
Note: Swallow the SR/ER 100mg tablet WHOLE with a full glass of water, preferably with food or milk to minimize gastric upset. Do NOT crush, chew, or break the tablet. Best taken at the same time each day.
Diclofenac exerts its therapeutic effects primarily by inhibiting the enzyme cyclooxygenase (COX), which is responsible for the conversion of arachidonic acid to prostaglandin precursors (prostaglandin G2/H2). This inhibition reduces the synthesis of prostaglandins (PGs), thromboxanes, and prostacyclins, which are key mediators of inflammation, pain, and fever.
Pregnancy: Category C (first and second trimesters): Use only if potential benefit justifies potential fetal risk. Avoid in third trimester (Category D) due to risk of premature closure of ductus arteriosus, delayed labor, and potential renal dysfunction in the neonate.
Driving: May cause dizziness, vertigo, or visual disturbances. Patients should be cautioned about operating machinery or driving if they experience these effects.
| Aspirin (low-dose) / Other NSAIDs | Increased risk of GI ulceration and bleeding; pharmacodynamic antagonism. | Major |
| Anticoagulants (Warfarin, Acenocoumarol) | Increased risk of bleeding due to antiplatelet effect and potential displacement from protein binding. | Major |
| ACE Inhibitors (Ramipril, Enalapril) / ARBs (Losartan) | Reduced antihypertensive effect; increased risk of renal impairment. | Major |
| Diuretics (Furosemide, Hydrochlorothiazide) | Reduced diuretic and antihypertensive efficacy; risk of renal failure. | Major |
| Corticosteroids (Prednisolone) | Synergistic increase in risk of GI ulceration and bleeding. | Major |
| Methotrexate | Decreased renal clearance of methotrexate, leading to increased toxicity (bone marrow suppression). | Major |
| Lithium | Decreased renal clearance of lithium, leading to increased serum levels and toxicity. | Major |
| Cyclosporine, Tacrolimus | Increased nephrotoxicity. | Major |
| SSRIs (Fluoxetine, Sertraline) | Increased risk of upper GI bleeding. | Moderate |
| Antidiabetics (Glibenclamide, Metformin) | May potentiate hypoglycemic effect; monitor blood glucose. | Moderate |
Same composition (Diclofenac (100mg)), different brands: