1. Clinical Overview
Nimesulide is a non-steroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic properties. It is a sulfonanilide derivative and a preferential cyclooxygenase-2 (COX-2) inhibitor. It is widely used in India for the short-term management of acute pain and primary dysmenorrhea. Its use is restricted to a maximum of 15 days due to hepatotoxicity concerns.
| Onset | Duration | Bioavailability |
|---|---|---|
| 15-30 minutes after oral administration. | Approximately 4-6 hours. | >90% following oral administration. |
2. Mechanism of Action
Nimesulide inhibits the synthesis of prostaglandins, key mediators of inflammation, pain, and fever, by blocking the cyclooxygenase (COX) enzyme pathway. It shows a preferential selectivity for the inducible COX-2 isoform over the constitutive COX-1 isoform. This may contribute to a lower incidence of gastrointestinal side effects compared to non-selective NSAIDs, though it does not eliminate the risk.
3. Indications & Uses
- Short-term management of acute pain
- Primary dysmenorrhea (painful periods)
4. Dosage & Administration
Adult Dosage: 100 mg twice daily, after meals. The tablet should be swallowed whole with a glass of water.
Administration: Take after food to minimize gastric irritation. The tablet should not be broken, chewed, or crushed. Treatment duration must not exceed 15 days.
5. Side Effects
Common side effects may include:
- Nausea
- Epigastric discomfort/ pain
- Diarrhea
- Dyspepsia
- Heartburn
- Skin rash
- Pruritus (itching)
- Dizziness
- Headache
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Warfarin, Acenocoumarol | Increased risk of bleeding due to displacement from protein binding sites and potential antiplatelet effect. | Major |
| Lithium | Decreased renal clearance of lithium, leading to increased lithium levels and toxicity. | Major |
| Methotrexate | Reduced renal clearance of methotrexate, increasing its hematologic and renal toxicity. | Major |
| Diuretics (Furosemide, Hydrochlorothiazide) | Reduced diuretic and antihypertensive efficacy; increased risk of renal impairment. | Moderate |
| ACE Inhibitors (Ramipril, Enalapril) / ARBs (Losartan) | Reduced antihypertensive effect; increased risk of renal impairment, especially in dehydrated patients. | Moderate |
| Corticosteroids (Prednisolone) | Increased risk of gastrointestinal ulceration and bleeding. | Moderate |
| Selective Serotonin Reuptake Inhibitors (SSRIs) e.g., Fluoxetine | Increased risk of upper gastrointestinal bleeding. | Moderate |
| Other NSAIDs (e.g., Diclofenac, Ibuprofen) | Increased risk of GI side effects and renal toxicity without therapeutic benefit. | Major |
| Cyclosporine, Tacrolimus | Increased risk of nephrotoxicity. | Major |
| Sulfonylureas (Glibenclamide, Glimepiride) | Enhanced hypoglycemic effect due to displacement from protein binding. | Moderate |
7. Patient Counselling
- DO take the tablet after food with a full glass of water.
- DO inform your doctor if you have a history of liver, kidney, heart, or stomach problems.
- DO inform your doctor about all other medicines you are taking, including over-the-counter drugs and supplements.
- DO stop the medication and contact your doctor immediately if you develop yellowing of skin/eyes (jaundice), dark urine, severe stomach pain, black tarry stools, vomiting blood, skin rash, or swelling of the face/lips.
- DONT take for more than 15 days unless specifically advised by your doctor.
- DONT crush, break, or chew the tablet.
- DONT take with other painkillers/NSAIDs (like ibuprofen, diclofenac) unless prescribed.
- DONT consume alcohol during treatment.
8. Toxicology & Storage
Overdose: Symptoms are generally dose-dependent and may include: nausea, vomiting, epigastric pain, gastrointestinal bleeding, lethargy, drowsiness, dizziness, headache, tinnitus, hypertension, acute renal failure, respiratory depression, coma, and rarely, hepatotoxicity. Convulsions have been reported.
Storage: Store below 30°C, in a cool, dry place, protected from light and moisture. Keep out of reach of children. Do not use after the expiry date printed on the pack.