Recommended Adult Rectal Dose of Diclofenac
The recommended adult rectal dose of diclofenac is 100 mg administered as a single dose. 1
Evidence-Based Dosing Recommendations
The strongest evidence for rectal diclofenac dosing comes from guidelines for preventing post-ERCP pancreatitis:
- The European Society of Gastrointestinal Endoscopy (ESGE) and European Association for the Study of the Liver (EASL) strongly recommend 100 mg of diclofenac administered rectally immediately before or after ERCP to prevent post-ERCP pancreatitis 1
- This recommendation is based on high-quality evidence and carries a strong recommendation grade 1
- Similarly, the British Society of Gastroenterology (BSG) guidelines also recommend 100 mg of diclofenac administered rectally at the time of ERCP 1
Clinical Applications and Timing
Rectal diclofenac administration is beneficial in several clinical scenarios:
Post-ERCP Pancreatitis Prevention
- Administer 100 mg rectally immediately before or after the procedure 1
- This is particularly important in high-risk patients (female sex, previous pancreatitis, difficult cannulation) 1
Postoperative Pain Management
- 100 mg administered rectally has been shown to reduce postoperative pruritus 1
- Rectal diclofenac (100 mg) can reduce postoperative pain when given after induction for abdominal surgery 1
Acute Pain Management
- Diclofenac provides good pain relief with a fast onset and long duration of action 2
Pharmacokinetic Considerations
- Rectal administration provides rapid and complete absorption 3
- The elimination half-life is relatively short (approximately 1.5 hours), but the drug persists in target tissues like synovial fluid 4
- Diclofenac is metabolized in the liver and eliminated through urinary and biliary excretion 4
Safety and Contraindications
Rectal diclofenac should be avoided in patients with:
- Hypersensitivity to NSAIDs
- Active gastrointestinal bleeding
- Severe renal impairment
- Concurrent use with other NSAIDs 5
Special Considerations
While the standard adult rectal dose is 100 mg, there is some evidence that lower doses may be effective in certain populations:
- A Japanese study found that even a 25 mg rectal dose was effective in preventing post-ERCP pancreatitis, which may be relevant for smaller patients 6
- However, the strongest guideline recommendations consistently support the 100 mg dose 1
Important Note
While some formulations of diclofenac are available for topical application or as patches (180 mg daily or twice daily) 1, these are not equivalent to rectal administration and should not be confused with the rectal dosing recommendations.