Cesarean section constitutes a public health priority (
1,
11) because it is one of the main surgeries in the obstetrics and gynecologist wards and its rate is increasing due to increased marital age, legal issues in obstetric/gynecologic ward, and socio-economic status of the community, and prevention of its postoperative complications is of great importance (
2). One of the main postoperative complications of cesarean is pain (
3). Several methods are available for pain relief after cesarean surgery (
12,
13), each with its performance and efficacy. Therefore in this study we compared the pain reduction effects of Diclofenac suppository and Paracetamol compared to intravenous Meperidine after the operation under spinal anesthesia. Results of this study indicated that combination therapy especially with using an analgesic with central effect similar to Paracetamol would have a greater efficacy than single-therapy without increasing the rate of complications.
In a study conducted by Gleeson and colleagues in England it was declared that Meperidine use caused analgesia in 87% of patients at postoperative phase (
14), but in our study this rate was 61.7% at the end of the 12 hours which is less than the results obtained in the mentioned study which could be due to the shorter follow-up period in our study in comparison with them. In a study conducted by Siddik and colleagues in London it was declared that Meperidine has good effects on pain relief after cesarean section (
15). In our study also Meperidine had a good effect in postoperative pain reduction in three of every five patients (about 60%). In a study conducted by Davis et al. in the United States, it was declared that using Paracetamol caused significant postoperative pain reduction (
16), which in this study this rate was 87% in Paracetamol and Diclofenac combination therapy.
In a study conducted by Kilicaslan and colleagues in Turkey it was declared that Paracetamol increases analgesia and reduces the need to Tramadol (
17) which is consistent with our findings in the current study. In a study conducted by Munishankar et al. in England it was declared that simultaneous use of Paracetamol and Diclofenac caused 38% reduction in the Morphine use in comparison to the use of Paracetamol alone (
18), which in our study combination therapy was significantly more effective than single-therapy. In a study conducted by Remy and colleagues it was declared that Acetaminophen use induced analgesic effect of Morphine postoperatively without changing the incidence of postoperative complications (
19). This synergic drug reaction in postoperative pain reduction by analgesic use was observed in our study using Diclofenac and Paracetamol.
In Wilder-Smith and associates study the effect of Diclofenac and Tramadol use in pain reduction after cesarean surgery was evaluated in 120 cases, and it was found that the effect of the two intramuscular drugs including Diclofenac 75 mg and Tramadol 100 mg simultaneously was significantly over the effects of each one alone in reducing pain after cesarean (
20), which the greater efficacy of combination therapy was approved in our study compared with single-therapy. In a research by Ong et al. it was concluded that combined use of Paracetamol and a nonsteroidal anti-inflammatory drug may have a greater analgesic effect compared with using each one separately (
21), which is consistent with our findings.
In a study in Sweden conducted by Legeby and colleagues on 50 women undergoing mastectomy, it was found that using Diclofenac suppositories with a dose of 100 mg reduced narcotic drugs consumption significantly up to 34% compared to placebo (
22), which our study also revealed the good effectiveness of Diclofenac use in combination with Paracetamol. In a study conducted by Fayaz et al. on 60 patients in England, it was found that using Diclofenac suppository with a dose of 100 mg as well as a combination of Diclofenac and Paracetamol had a significant effect on reducing the need for narcotic drugs use in comparison with placebo (
23), which is in line with our study findings.
In a study by Sylaidis and colleagues conducted on twenty patients in England it was stated that a single 100 mg rectal dose of Diclofenac had a good effect on reduction of postoperative pain and the need to use other narcotic analgesics (
24) which complies with our study findings. Also another study by Hosseini Jahromi et al. (
25) evaluated the effects of suppository Acetaminophen, Bupivacaine Wound Infiltration, and Caudal Block with Bupivacaine on postoperative pain in management of inguinal herniorrhaphy in children, and it was seen that bupivacaine infiltration and caudal block with bupivacaine provide better analgesia than suppository acetaminophen. However in our study also the combination treatment resulted in a better analgesic response.
Totally, according to the results of this study and comparison with other studies performed in this field of health, it may be concluded that combination of Diclofenac and Paracetamol effectiveness is far better at reducing pain after cesarean section and the amount of required analgesics compared to Meperidine. However further studies are required to confirm and validate the findings obtained in the current study.