Diclofenac Epolamine

In an open‑label exploratory study using microdialysis in healthy volunteers, topical diclofenac epolamine plasters (180 mg over 4 days) did not alter resting or exercise‑induced interstitial PGE₂ concentrations in the vastus lateralis muscle. However, unlike the baseline phase where PGE₂ increased significantly during recovery from exercise, after diclofenac treatment no such rise occurred, suggesting the plaster limits the post‑exercise inflammatory prostaglandin surge. The isoprostane 8‑iso‑PGF₂α, formed via free radical‑catalyzed lipid peroxidation independent of cyclooxygenases, was unaffected by either exercise or diclofenac. Local and systemic diclofenac concentrations were variable but consistent with prior pharmacokinetic studies.

Fig. 1 Mean ± SD PGE2 microdialysate concentrations (pg ml−1) measured on day 0 (baseline) and on day 4 of treatment at rest, during dynamic exercise and during the recovery interval (n = 12). (Burian A, et al., 2013)

In an open‑label phase IV study, 104 children aged 6–16 years with minor soft tissue injuries received the FLECTOR diclofenac epolamine topical system twice daily for up to 14 days. Local tolerability was excellent (maximum redness score 1, faint redness). Fourteen nonserious adverse events possibly related to treatment occurred in nine patients (8.7%). Pain relief was somewhat greater in the younger cohort (6–11 years), who also had higher plasma diclofenac concentrations (2.49 vs. 1.11 ng/mL at last assessment). The patch safely provided effective analgesia with minimal systemic NSAID exposure and low local toxicity.

Fig. 2 Change from baseline in pain scores. (Jones CA, et al., 2022)