Transdermal nitroglycerine patch as a coadjuvant analgesic to morphine or diclofenacy for postoperative pain management

ABSTRACT

The aim of this study was to determine whether the application -of transdermal nitroglycerine patch would prolong postoperative analgesia associated with morphine or diclofenac in patients undergoing abdominal, orthopedic and gynecological surgeries under general anaesthesia. The study was conducted on 60 ASA I and II patients of both sexes, aged 22-62 years old, divided into 5 groups. Nitroglycerine group [NG] received 5 mg nitroglycerine alone, morphine group [MG] received 10 mg morphine alone, diclofenac group [DG] received 75 mg diclofenac alone, nitroglycerine-morphine group [NMG] received 5 mg nitroglycerine and 10 mg morphine and finally nitroglycerine-diclofenac group [NDG] received 5 mg nitroglycerine and 75 mg diclofenac. In all groups we used a standard anaesthetic technique and the study medications were given immediately after end of surgery and anaesthesia. Postoperative assessment included pain scores [VAS] for 24 hours, time of first rescue analgesic medication and its pain score, total dose of additional analgesic used within 24 hours and lastly adverse reactions. Our results showed that although neither morphine, diclofenac nor nitroglycerine alone delayed the time to administration of first rescue analgesic medication, the association of 5 mg/day transdermal nitroglycerine and 10 mg, morphine or 75 mg diclofenac resulted in an average of 12 hours, or 8 hours respectively of postoperative analgesia compared with 6 hours for morphine group and 4.5 hours for diclofenc group. We concluded that transdermal nitroglycerine was effective coadjuvant analgesic to morphine or diclofenac for postoperative pain management but more investigations may be required