Diclofenac
Mechanism :
Diclofenac sodium is a nonsteroidal anti-inflammatory drug (NSAID) that exhibits anti-inflammatory, analgesic, and antipyretic activities. The mechanism of action is not completely understood but may be related to prostaglandin synthetase inhibition.
Indication :
- Juvenile idiopathic arthritis
Contraindications :
Diclofenac sodium is contraindicated in patients with known hypersensitivity to diclofenac and should not be given to patients who have experienced asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. Severe, rarely fatal, anaphylactic-like reactions to NSAIDs have been reported in such patients.
Dosing :
Under 3 years:
Safety and efficacy not established.
>3 years:
2-3 mg/kg/day orally for upto one month.
Adverse Effect :
Nausea, diarrhea, bleeding, ulceration, headache, dizziness, vertigo, hypersensitivity reactions e.g. bronchospasm, rashes, local discomfort, burning or itching. Nephrotic like syndrome rarely.
Interaction :
Aspirin: When administered with aspirin, its protein binding is reduced.
Methotrexate: NSAIDs could enhance the toxicity of methotrexate.
Cyclosporine: May increase cyclosporine nephrotoxicity.
ACE-inhibitors: May diminish the antihypertensive effect of ACE inhibitors.
Diuretics: Can reduce the natriuretic effect of furosemide and thiazides in some patients. This response has been attributed to inhibition of renal prostaglandin synthesis.
Lithium: NSAIDs have produced an elevation of plasma lithium levels and a reduction in renal lithium clearance.
Warfarin: The effects of warfarin and NSAIDs on GI bleeding are synergistic, such that users of both drugs together have a risk of serious GI bleeding higher than users of either drug alone.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function, but avoid if possible |
| <10 | Dose as in normal renal function, but only use if on dialysis |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in normal renal function. |
| HD | Not dialysed. Dose as in normal renal function. |
| HDF/High flux | Not dialysed. Dose as in normal renal function. |
| CAV/VVHD | Not dialysed. Dose as in normal renal function |
Hepatic Dose :
Use with caution. Start with lower dose. Immediately discontinue diclofenac if hepatic disease develops or if systemic manifestations occur (e.g., eosinophilia, rash, etc.) and abnormal liver tests are detected, persist, or worsen.