Intravenous dexketoprofen induces less injection pain than racemic ketoprofen

Ketoprofen has high analgesic efficacy against inflammatory and nociceptive pain. Additionally, when ketoprofen is administered in conjunction with an opioid during pain management, it prevents the development of opioid-induced hyperalgesia. The main limitation for racemic ketoprofen IV administration is venous irritation. Dexketoprofen is the active enantiomer of racemic ketoprofen and has a similar analgesic efficacy in a dose proportion of 1 : 2, but it causes fewer adverse effects than racemic ketoprofen. It has been claimed that dexketoprofen may cause less frequent and less severe injection pain than racemic ketoprofen. In this study, we compared the injection pain of IV administered racemic ketoprofen and dexketoprofen in elective surgical patients.

The ethics committee of our institution approved this randomized, double-blinded, two-treatment, two-period, crossover clinical comparison of ketoprofen and dexketoprofen. A total of 221 ASA I-III adult patients, aged 20-75 years, were initially IV administered either 0·5 mg/kg racemic ketoprofen followed 2 h later with 0·25 mg/kg dexketoprofen (group 1) or vice versa (group 2). Both compounds were diluted in 20 mL of normal saline and were injected over 6 min. Patients reported injection pain on an 11-point numerical rating scale (NRS) (0 = no pain, 10 = most pain).

Significantly less injection pain was reported after dexketoprofen administration. A total of 201 of 209 patients reported pain during racemic ketoprofen injection, and 157 of 210 patients reported pain during dexketoprofen injection, respectively. Moderate or severe pain was reported by 90 (41%) patients during racemic ketoprofen administration and by 43 (20%) during dexketoprofen injection (P = 0·001). The mean of injection pain during racemic ketoprofen injection was 4·2 (SD 2·5) and was 2·5 (2·4) during dexketoprofen injection (P = 0·001). No serious or unexpected adverse events were reported.

Dexketoprofen causes significantly less injection pain than racemic ketoprofen; therefore, it may be a more suitable IV non-steroidal anti-inflammatory than the racemate.