Aceclofenac Time of Action
Aceclofenac 150 mg as a single dose has not been proven effective for acute pain relief and should not be used in this setting; the standard dosing is 100 mg twice daily, though specific onset and peak effect data are limited in the literature. 1
Evidence for Acute Pain Relief
The only systematic review examining aceclofenac in acute postoperative pain found that a single 150 mg dose could not be distinguished from placebo in patients with established pain, while ibuprofen 400 mg in the same trial was clearly superior to placebo. 1 This Cochrane review concluded that in the absence of evidence for efficacy in acute postoperative pain, aceclofenac use in this indication is not justified. 1
Standard Dosing Regimen
- The usual oral dosage is 100 mg twice daily for adults with musculoskeletal pain and inflammatory conditions. 2
- A controlled-release formulation (200 mg once daily) is bioequivalent to conventional aceclofenac and has been studied for 4-week therapy in musculoskeletal pain. 3
- The twice-daily dosing suggests that aceclofenac requires repeated administration rather than single-dose acute pain management. 2, 4
Comparative Context with Other NSAIDs
Oral NSAIDs as a class provide pain relief within less than 2 hours for acute musculoskeletal injuries, with moderate-certainty evidence showing a weighted mean difference of -0.93 cm on a 10-cm visual analog scale compared to placebo. 5 However, aceclofenac specifically was not included in these high-quality guideline analyses, suggesting it is not a preferred agent for acute pain management. 5
Duration of Analgesic Effect
- Aceclofenac 100 mg has been described as having more prolonged analgesic efficacy than acetaminophen 650 mg, though specific duration data were not provided. 4
- In chronic conditions like osteoarthritis, aceclofenac demonstrates sustained efficacy over 12 weeks with significant pain reduction (76-86% of patients reporting improvement). 6
- The twice-daily dosing requirement suggests an approximate 12-hour duration of action. 2
Clinical Implications
For acute musculoskeletal pain, other NSAIDs with proven efficacy should be preferred over aceclofenac. The American College of Physicians and American Academy of Family Physicians guidelines support oral NSAIDs for acute pain relief at less than 2 hours and sustained relief at 1-7 days, but these recommendations are based on agents like ibuprofen and diclofenac, not aceclofenac. 5
The lack of demonstrated efficacy in acute pain studies raises questions about aceclofenac's use even in other indications, despite its theoretical similarity to diclofenac. 1 Given the availability of multiple effective NSAIDs with established acute pain efficacy, aceclofenac should be reserved for chronic inflammatory conditions where its potentially better gastrointestinal tolerability profile may offer advantages. 4, 6