Differential analgesic effect of tenoxicam on the wound pain and uterine cramping pain after cesarean section

The analgesic effect of transversalis fascia plane block after caesarean section under spinal anaesthesia with intrathecal morphine: a randomised controlled trial

We aimed to test whether bilateral injection of bupivacaine 0.25% in the transversalis fascia plane reduced 24 h opioid dose after singleton caesarean section, under spinal anaesthesia with intrathecal morphine, compared with saline 0.9% injectate. We allocated randomly 52 women to bilateral injection of 20 ml saline 0.9% on arrival in the post-anaesthesia care unit and 54 women to bilateral injection of 20 ml bupivacaine 0.25% (with adrenaline 2.5 μg.ml-1 ). Mean (SD) cumulative morphine equivalent opioid dose 24 h after saline injection was 32.3 (28.3) mg and 18.7 (20.2) mg after bupivacaine injection, a mean (95%CI) difference of 13.7 (4.1-23.2) mg (p = 0.006). Median (IQR [range]) time to first postoperative opioid dose was 3.0 (1.5-10.3 [0.0-57.4]) h after saline 0.9% and 8.2 (2.7-29.6 [0.2-55.4]) h after bupivacaine 0.25% (p = 0.054). Transversalis fascia plane with bupivacaine 0.25% with adrenaline reduced postoperative pain at rest during 48 h (0-10-point scale) by a mean (95%CI) of 0.9 (0.2-1.6) points (p = 0.013) and on movement by 1.2 (0.4-2.1) points (p = 0.004). We conclude that transversalis fascia plane bupivacaine 0.25% with adrenaline reduces pain and opioid dose after caesarean section compared with saline 0.9%.

Comparison of different nonsteroidal anti-inflammatory drugs for cesarean section: a systematic review and network meta-analysis

BACKGROUND

Cesarean section is associated with moderate to severe pain and nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly employed. The optimal NSAID, however, has not been elucidated. In this network meta-analysis and systematic review, we compared the influence of control and individual NSAIDs on the indices of analgesia, side effects, and quality of recovery.

METHODS

CDSR, CINAHL, CRCT, Embase, LILACS, PubMed, and Web of Science were searched for randomized controlled trials comparing a specific NSAID to either control or another NSAID in elective or emergency cesarean section under general or neuraxial anesthesia. Network plots and league tables were constructed, and the quality of evidence was evaluated with Grading of Recommendations Assessment, Development and Evaluation (GRADE) analysis.

RESULTS

We included 47 trials. Cumulative intravenous morphine equivalent consumption at 24 h, the primary outcome, was examined in 1,228 patients and 18 trials, and control was found to be inferior to diclofenac, indomethacin, ketorolac, and tenoxicam (very low quality evidence owing to serious limitations, imprecision, and publication bias). Indomethacin was superior to celecoxib for pain score at rest at 8-12 h and celecoxib + parecoxib, diclofenac, and ketorolac for pain score on movement at 48 h. In regard to the need for and time to rescue analgesia COX-2 inhibitors such as celecoxib were inferior to other NSAIDs.

CONCLUSIONS

Our review suggests the presence of minimal differences among the NSAIDs studied. Nonselective NSAIDs may be more effective than selective NSAIDs, and some NSAIDs such as indomethacin might be preferable to other NSAIDs.

Intravenous patient-controlled analgesia regimen in postoperative pain management following elective cesarean section: A single-center retrospective evaluation

Intravenous patient-controlled analgesia (IV PCA; IVA) is the most widely used method for postoperative pain management. An appropriate IVA regimen is required, depending on the expected intensity of pain after surgery. This study expected that a decrease in the second prescription rate of IVA after elective cesarean section (CS) would help establish an appropriate regimen for the initial IVA. We retrospectively reviewed the records of 632 patients who were prescribed IVA after CS. We classified patients into phase 1 (basal rate 15.00 mcg/hours, bolus dose 15.00 mcg, total volume 100 mL) and phase 2 (basal rate 31.25 mcg/hours, bolus dose 31.25 mcg, nefopam 60 mg, paracetamol 3 g, total volume 160 mL) according to the IVA regimen, and patients in phase 2 were classified into the basal 15 group and basal 30 group according to the basal rate of IVA. We compared the rates of second prescription, drug removal, and side effects of IVA between the 2 phases and the 1 group. We analyzed the data of 631 eligible patients. The second prescription rate of IVA in phase 2 was 3.77%, a significant decrease compared to that in phase 1 (27.48%); however, the incidence of complications in phase 2 was 6.92%, a significant increase compared to that in phase 1 (0.96%). Within phase 2, in the basal 30 group, the basal rate was almost double that in the basal 15 group. However, there were no significant differences in the rate of second prescription, removed drug IVA, or adverse events between the basal 15, and 30 groups. In the case of CS, which has a high degree of postoperative pain, it is beneficial to control acute pain by properly setting the regimen of the initial IVA with a basal rate infusion to nullify a second prescription.

Nalbuphine May Be Superior to Sufentanil in Relieving Postcesarean Uterine Contraction Pain in Multiparas: A Retrospective Cohort Study

Purpose

Postcesarean pain remains a major complaint from puerperium women who have undergone cesarean section, especially uterine contraction induced visceral pain. The optimal opioid for pain relief after cesarean section (CS) is still unclear. The goal of this study was to compare the analgesic effect of Nalbuphine to Sufentanil in patients who underwent CS.

Patients and Methods

In this single-center retrospective cohort study, we included patients who received Nalbuphine or Sufentanil Patient-Controlled Intravenous Analgesia (PCIA) after CS between 1 January 2018 and 30 November 2020. Data on a Visual Analog Scale (VAS) at uterine contraction, at rest, and at movement, analgesic consumption, and side effects were collected. We performed logistic regression to identify predictors of severe uterine contraction pain.

Results

A total of 674 patients were identified in the unmatched cohort, and 612 patients in the matched one. Compared to the Sufentanil group, lower VAS-contraction was recorded in the Nalbuphine group in both the unmatched and matched cohorts, the mean difference (MD) on POD1 was 0.35 (95% CI: 0.17 to 0.54, p<0.001) and 0.28 (95% CI: 0.08 to 0.47, p<0.001), respectively, and the MD of POD2 was 0.12 (95% CI: 0.03 to 0.40, P=0.019) and 0.12 (95% CI: 0.03 to 0.41, P=0.026), respectively. On POD1 but not POD2, VAS-movement was lower in the Nalbuphine group as compared to the Sufentanil group. No difference was found between VAS-rest on POD1 and POD2 in both unmatched and matched cohorts. Less analgesic consumption, and side effects were recorded in the Nalbuphine group. Logistic regression indicated that multipara and analgesic consumption were risk factors for severe uterine contraction pain. In subgroup analysis, VAS-contraction was meaningfully reduced in the Nalbuphine group compared with the Sufentanil group in multipara patients, but not primiparas.

Conclusion

Compared to Sufentanil, Nalbuphine may provide better analgesia on uterine contraction pain. The superior analgesia may only exhibit in multiparas.

Analgesic outcomes of tramadol alone and in combination with Butorphanol or Flurbiprofen Axetil after cesarean section: a retrospective study with propensity score matching analysis

BACKGROUND

The Society for Obstetric Anesthesia and Perinatology recommends a multimodal analgesia regimen for cesarean delivery analgesia. This study aimed to compare the analgesic effects of tramadol alone and combined with butorphanol or flurbiprofen axetil after a cesarean section.

METHODS

We performed a retrospective analysis based on the electronic medical records of a teaching hospital in China from January 2018 to January 2020. We collected data on demographic characteristics, anesthesia, analgesia strategy, and pain intensity postoperatively during the first 48 hours. Inadequate postoperative analgesia during this period was defined as an NRS score ≥ 4. We also collected data regarding off-bed activity and intestinal function recovery. Participants were classified into three groups according to analgesia regimens. Groups T, TF, and TB received tramadol, a mixture of tramadol and flurbiprofen axetil, and a combination of tramadol and butorphanol, respectively. Analgesic outcomes were compared using propensity score matching analysis.

RESULTS

Data from 2323 cases of caesarean section were included in the analysis, and 521 pairs were matched in each group according to their propensity score. Compared with group T, The inadequate analgesia on pain at rest and pain at movement was lower in group TF (RR: 0.42, 95% CI: 0.36-0.49, P = 0.001 and RR: 0.58, 95% CI: 0.48-0.69, P < 0.001, respectively),and the incidence of inadequate control of pain at movement was higher in group TB (RR: 1.38, 95% CI: 1.22-1.55, P < 0.001). Additionally, the percentage of off-bed activity at 2 days postoperatively was higher in group TB than in groups TF and T (78.7% vs. 68.5 and 78.7% vs. 64.9%, respectively, P < 0.001). The incidence of intestinal function recovery 2 days after cesarean delivery in group TB was higher than that in group TF (73.3% vs. 66.2%, P = 0.013).

CONCLUSIONS

Combining tramadol and flurbiprofen axetil could enhance the analgesic effect and be safely used for analgesia after a cesarean section. However, combining tramadol and butorphanol may produce an antagonistic effect.

Sufentanil Combined with Nalbuphine via Patient-Controlled Intravenous Analgesia After Cesarean Section: A Retrospective Evaluation

Purpose

This retrospective study evaluated the efficacy, opioid consumption, and safety profile of two patient-controlled intravenous analgesia (PCIA) regimens (sufentanil combined with nalbuphine vs sufentanil alone) after cesarean section (CS).

Patients and Methods

Parturients (n = 1808) received sufentanil combined with nalbuphine (SN group) or sufentanil alone (S group) as PCIA after CS. The primary outcome was the numeric rating scale (NRS) pain score with movement (NRS-M) at 24 h after CS. Secondary outcomes were NRS scores at rest (NRS-R) at 24 and 48 h after CS, NRS-M at 48 h after CS, cumulative PCIA bolus times, and opioid consumption during the first 24 and 48 h postoperatively, which was measured in morphine-equivalent doses.

Results

The population comprised 993 and 815 subjects in the SN and S groups, respectively. At 24 and 48 h after CS, the respective NRS-M scores of the SN group (4.62, 3.37) were each significantly lower than those of the S group (5.18, 4.01; P < 0.01 for both). The corresponding NRS-S scores were similarly lower in the SN group (0.96, 0.19) than in the S group (2.05, 0.92; P < 0.01 for both). After adjusting for covariates, the SN group still had lower NRS-M than the S group at 24 h after CS (estimate adjusted = 0.565, P < 0.001). The PCIA bolus times were significantly lower in the SN group than in the S group. The rates of bradycardia and respiratory depression were lower in the SN group than in the S group. However, the rates of dizziness and postoperative hypotension were slightly higher in the SN group, and those of nausea/vomiting were comparable.

Conclusion

Compared with sufentanil alone, sufentanil combined with nalbuphine for PCIA provided superior analgesia in parturient women after CS.

Effectiveness of Patient-Controlled Intravenous Analgesia (PCIA) with Sufentanil Background Infusion for Post-Cesarean Analgesia: A Randomized Controlled Trial

Purpose

To investigate the effectiveness of sufentanil patient-controlled intravenous analgesia pump (PCIA) and background infusion in patients of post-cesarean analgesia.

Patients and Methods

This trial compared two groups of women undergoing cesarean section and receiving PCIA: no background infusion group (n=30), 6-min lockout time, and background infusion group (n=30), 2 mL/h infusion, 10-min lockout time. Both groups with 2 μg/kg sufentanil was diluted to 100 mL with normal saline. VAS scores at rest at 36 h was the primary endpoint. The secondary endpoints were the VAS scores at rest at 6, 12, and 24 h, the total amount of sufentanil consumed, the Ramsay sedation score (RSS) assessed at the same time points, postpartum bleeding within 24 h, the injection/attempt (I/A) ratio, BP and HR, PONV, side effects of sufentanil.

Results

Compared with the no background infusion group, the background infusion group showed lower VAS pain scores at 6, 12, and 24 h (P<0.01), but no differences at 36 h (95% CI = -0.5-0.8. P>0.05). Attempts, injections, and total sufentanil consumption were significantly different between the two groups (P<0.001), but without difference in I/A. Bleeding was less in the background infusion group at 1 h (P=0.03). The minimal respiration rates were not significantly different between groups.

Conclusion

Background infusion increased the total consumption of sufentanil within 36 h after cesarean section. Although it did not reduce uterine contraction pain and wound pain at 36 h, it significantly reduced the pain at 6, 12, and 24 h after cesarean section. It improved patient satisfaction and reduced the amount of bleeding after 1 h. Importantly, it did not increase the incidence of hypertension, PONV and respiratory depression.

Solid Dispersion of Tenoxicam – HPMC by Freeze-Drying: Solid State Properties, Dissolution Study, and Analgesic Activity in Mice

AIM: The aim of this study was to prepare solid dispersion of tenoxicam with hydroxypropyl methylcellulose (HPMC) to improve solubility, dissolution rate, and in vivo analgesic activity. METHODS: Solid dispersion of tenoxicam with HPMC was prepared using the freeze-drying technique in three ratios of drug to carrier (1:1, 1:2, and 2:1 w/w). The s olid-state properties of solid dispersion powders were characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR) spectroscopy, and scanning electron microscope (SEM). Solubility and dissolution rate studies were conducted in an aqueous medium. Analgesic activity was evaluated using the writhing method. RESULTS: Analysis of PXRD and DSC results indicated a decreased degree of crystallinity of tenoxicam in solid dispersion powders. Solid dispersion of tenoxicam exhibited a significant improvement in solubility and dissolution rate compared to intact tenoxicam, in line to the increment on the ratio of HPMC. Analgesic activity study revealed that solid dispersion 1:2 was more effective than intact tenoxicam. CONCLUSIONS: This study concludes that the solid dispersion technique is a promising strategy to improve the solubility and dissolution rate of tenoxicam.

Programmed Intermittent Epidural Bolus in Comparison with Continuous Epidural Infusion for Uterine Contraction Pain Relief After Cesarean Section: A Randomized, Double-Blind Clinical Trial

Purpose

Programmed intermittent epidural bolus (PIEB) was reported to provide superior maintenance of labour analgesia with better pain relief and less motor block than continuous epidural infusion (CEI). Whether this is also evident for uterine contraction pain relief after cesarean section remains unknown.

Patients and Methods

Parturients scheduled for cesarean section were recruited for the study. At the end of the surgery, after a similar epidural loading dose given, patients received either PIEB (6 mL·h⁻¹) or CEI (6 mL·h⁻¹) of 0.1% ropivacaine. The primary outcome was the uterine contraction pain assessed with visual analog scale (VAS-U) at the postoperative 36 h. Secondary outcomes included incision pain at the rest (VAS-R) and in the movement-evoked (VAS-P), and lower extremity motor block (defined as Bromage score > 0). The whole profile of VAS scores between groups was analyzed using linear mixed model. When significant differences were found, the pairwise comparison was done with the Mann Whitney U-test followed by Bonferroni correction.

Results

One hundred and twenty parturients were studied (PIEB, 60; CEI, 60). VAS-U at the postoperative 36 h in the PIEB group was lower than in the CEI group (Bonferroni-adjusted P < 0.01). The linear mixed model indicated that VAS-U, VAS-R and VAS-P were lower in the PIEB group compared with the CEI group (all P < 0.01). Motor block was higher in the CEI group than in the PIEB group during the study period except 2 h (all P < 0.05). No differences of adverse events such as hypotension and urinary retention were observed between the two groups.

Conclusion

Programmed intermittent epidural bolus provides more effective uterine contraction and incision pain relief and less motor block after cesarean section than continuous epidural infusion without an increased risk of urinary retention and blood pressure instability.

Evaluation of ultrasound-guided bilateral low thoracic erector spinae plane block for postoperative analgesia in cesarean delivery patients: a prospective, randomized, controlled clinical trial

BACKGROUND

Erector spinae plane block (ESPB) is a recently described block. In many reports, ESPB has been reported to provide effective postoperative analgesia in patients undergoing cesarean delivery (CD). Herein, we compared the effectiveness of ESPB and control group in postoperative analgesia in patients undergoing CD under spinal anesthesia.

METHODS

This assessor blinded, prospective, randomized, efficiency study was conducted in the postoperative recovery room and ward at a tertiary university hospital. Eighty-six patients (ASA II-III) were recruited. Following exclusion, 80 patients were randomized into two equal groups (block and control group). Standard multimodal analgesia was performed in the control group while ESPB block was performed in the intervention (ESPB) group. Opioid consumption was measured and pain intensity between groups was compared using Numeric Rating Scores (NRS).

RESULTS

NRS was lower in Group ESPB at 3rd and 6th hours. There was no difference between NRS scores at other hours. Opioid consumption was lower in Group ESPB.

CONCLUSION

When added to multimodal analgesia, bilateral ultrasound guided low thoracic ESPB leads to improve the quality of analgesia in the first 24 hours in patients undergoing CD.

Comparison of postoperative pain between patients who underwent primary and repeated cesarean section: a prospective cohort study

BACKGROUND

The differences in post-operative pain are unclear between the primiparas who underwent a primary cesarean section and multiparas who underwent their first repeat cesarean section. The study aimed to explore the possible differences in postoperative pain between primiparas and multiparas.

METHODS

A prospective cohort study was performed only including women who underwent cesarean deliveries under spinal anesthesia. Postoperative patient-controlled intravenous analgesia (PCIA) was administered to all subjects with 0.2 mg/kg hydromorphone and 4 mg/kg flurbiprofen; the pump was programmed as 2.0 mL/h background infusion with a loading dose of 1 mL and a lockout period of 15 min. Postoperative incision and visceral pain intensity were evaluated using the visual analogue scale, and inadequate analgesia was defined as a visual analogue scale score ≥ 40 during 48 h post-operation. Additionally, the patients' pain statuses in postoperative week 1 and week 4 were also assessed during follow-up via telephone.

RESULTS

From January to May 2017, a total of 168 patients (67 primiparas and 101 multiparas) were included. The relative risk for multiparas to experience inadequate analgesia on incision pain was 0.42 (95% CI: 0.25 to 0.74) compared to primiparas. In patients aged < 30 years, inadequate analgesia on visceral pain was higher in multiparas than in primiparas (RR, 3.56 [1.05 to 12.04], P = 0.025). There was no significant difference in the combined incidence of inadequate analgesia in both types of pain between the multiparas and primiparas (33.7% vs. 40.2%, P = 0.381). No difference was found in PCIA use between the two groups (111.1 ± 36.0 mL vs. 110.9 ± 37.3 mL, P = 0.979). In addition, a significantly higher incidence of pain was noted 4 weeks post-surgery in primiparas than that in multiparas (62.2% vs. 37.7%, P = 0.011).

CONCLUSION

Multiparas who underwent their first repeat cesarean section have a lower for inadequate analgesia on incision pain during the first 48 h after surgery than primiparas. Multiparas aged under 30 years may be more prone to experiencing postoperative inadequate analgesia on visceral pain.

TRAIL REGISTRATION

ClinicalTrial.gov: NCT03009955 , Date registered: December 30, 2016.

The Analgesic Efficacy of Nonsteroidal Anti-inflammatory Agents (NSAIDs) in Patients Undergoing Cesarean Deliveries: A Meta-Analysis

BACKGROUND AND OBJECTIVES

Postoperative pain after cesarean delivery, which accounts for approximately 1 in 3 live births in the United States, can be severe in many patients. Nonsteroidal anti-inflammatory agents (NSAIDs) are potent analgesics that are effective in the treatment of postoperative pain. In this meta-analysis, we assessed the analgesic efficacy of NSAIDs in postoperative cesarean delivery patients.

METHODS

An electronic literature search of the Library of Medicine's PubMed, Cochrane CENTRAL, Scopus, and EMBASE databases was conducted in May 2013 and updated in January 2015 (Appendix, Supplemental Digital Content 1, http://links.lww.com/AAP/A174). Searches were limited to randomized controlled trials. The primary outcome variable was visual analog scale or numerical rating scale pain scores. Secondary outcomes included cumulative postoperative opioid consumption and opioid-related adverse effects (drowsiness/sedation, nausea, and vomiting). Data extraction was performed independently by 2 reviewers. Extracted data were input into Review Manager.

RESULTS

Twenty-two randomized controlled trials compared a NSAID (n = 639) to a control (n = 674). Patients in the NSAID group versus control reported lower pain scores at 12 hours (P = 0.003) and at 24 hours (P < 0.001). Subgroup analysis showed a significant difference in pain scores at 24 hours, with patients receiving NSAIDs via intravenous/intramuscular (P < 0.001) route, but not the oral (P = 0.39) or rectal routes (P = 0.99). Significantly lower average pain scores were reported for pain with movement at 24 hours in the NSAID group (P = 0.001). Patients in the NSAID group versus controls consumed significantly less opioids (P < 0.001) and had significantly less drowsiness/sedation (P = 0.03), but there was no significant difference between the groups with regard to nausea or vomiting (P = 0.48 and P = 0.17, respectively).

CONCLUSIONS

The perioperative use of NSAIDs in cesarean delivery patients will result in a significantly lower pain scores, less opioid consumption, and less drowsiness/sedation but no difference in nausea or vomiting compared to those who did not receive NSAIDs. Further research should address the optimal NSAID regimen and examine the effect of improved analgesia on patient-centered outcomes such as patient satisfaction and quality of breastfeeding.

The use of tenoxicam to prevent symptoms of discomfort induced by vagotonia during uterus manipulation in cesarean sections

PURPOSE

Symptoms such as nausea, vomiting, tightness of the chest, bradycardia, and shoulder or abdominal discomfort, caused by vagotonia occurring during uterus manipulation, have concerned healthcare professionals for some time. Patients sometimes report these symptoms when undergoing spinal anesthesia for cesarean sections (CSs). We designed a prospective, double-blind study to investigate the effectiveness of tenoxicam in preventing these symptoms of discomfort.

METHODS

A total of 105 American Society of Anesthesiologists (ASA) class I-II nulliparous pregnant women, who were scheduled for a CS, were enrolled into this prospective, double-blind study. Spinal anesthesia was conducted to reach a peak dermatome level of no more than T3. The 100 patients were randomly divided into 2 groups having completed study course: Group T (N = 50) received a 20 mg dose of tenoxicam in 5 mL of normal saline (NS) immediately after skin incision and Group N (N = 50) only received 5 mL NS. The incidence and severity of the symptoms experienced by the patients were recorded by a nurse anesthetist who was blinded to the injection regimen the patients were receiving. A chi-square test was used for statistical analysis t test and P < .05 was defined as significant.

RESULTS

The incidence and degree of severity of nausea and vomiting were same in both the groups. The incidence and degree of severity of bradycardia, nausea, vomiting, tightness of the chest, shoulder discomfort, and abdominal discomfort were lower in Group T than in Group N.

CONCLUSION

Tenoxicam might theoretically block the parasympathetic vagus pathway and decrease the visceral pain or visceral-specific symptoms, alleviating the symptoms caused by vagotonia. However, the prophylactic effect of tenoxicam in reducing the incidence and severity of nausea and vomiting was not statistically significant. This could be because nausea and vomiting are not solely caused by vagotonia, but also by other mechanisms.

Single dose oral tenoxicam for acute postoperative pain in adults

BACKGROUND

Tenoxicam is a non-steroidal anti-inflammatory drug (NSAID) licensed for use in rheumatic disease and other musculoskeletal disorders in the UK, and is widely available in other countries worldwide. This review sought to evaluate the efficacy and safety of oral tenoxicam in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral tenoxicam in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched The Cochrane Library (Issue 1, 2009), MEDLINE (March 2009); EMBASE via Ovid (March 2009); the Oxford Pain Relief Database.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral tenoxicam for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with tenoxicam experiencing least 50% pain relief over 4 to 6 hours, using validated equations. The number needed to treat to benefit (NNT) was calculated using 95% confidence intervals (CI). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected.

MAIN RESULTS

Not one of sixteen studies identified by the searches and examined in detail studied oral tenoxicam in patients with established postoperative pain and therefore no results are available.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral tenoxicam in acute postoperative pain, its use in this indication is not justified at present. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes which are effective, there is no urgent research agenda for this particular drug.

Improving tenoxicam solubility and bioavailability by cosolvent system

The formulation study of tenoxicam, a poorly water-soluble drug, was developed by use of a ternary cosolvent system and has significantly enhanced the solubility. Additionally, the relative bioavailability of testing formulation was also evaluated by New Zealand rabbit with a single i.m. injection. The three-phase diagram for dimethylsulfoxide (DMSO)/propylene glycol/water, DMSO/ethanol/water, and DMSO/polyethoxylated castor oil/ethanol system was developed. The volume ratio of 5:4:1 in the DMSO/polyethoxylated castor oil/ethanol system resulted in a more suitable vehicle than other systems, with a high solubility (20.73 mg/ml) and low viscosity (10.0 Cp). A pharmacokinetic study of bioequivalence (F (rel) = 0.89) was also obtained. The present study not only provides a novel strategy improving tenoxicam solubility but also helps further scientific knowledge for the development of parenteral formulations.

Postcesarean analgesia: effective strategies and association with chronic pain

PURPOSE OF REVIEW

The management of postoperative pain after cesarean section slightly differs from that of the general surgical population, specifically women need to recover quickly to take care of their newborn baby. Optimal pain management is imperative for the success of immediate-term and long-term rehabilitation and this principle applies to obstetric patients. There is growing evidence that perioperative pain management has consequences extending well beyond the immediate recovery period. Unrelieved postoperative pain is a striking risk factor for the development of residual pain.

RECENT FINDINGS

A recent study has highlighted that chronic pain may be a significant clinical problem after cesarean section. Among the risk factors, recalls of severe acute postoperative pain led to the reconsideration of postoperative pain management after cesarean delivery. Current published data agree that drug combinations, that is, multimodal or balanced analgesia, are mandatory to achieve satisfactory and effective pain relief with reduced side effects.

SUMMARY

The use of balanced analgesia has significantly improved acute pain management after cesarean section. Future studies should extend their investigations beyond the first 48 h and consider the long-term effects of different analgesic regimens, that is, those that alter the development of residual pain.

Chimeric DNA vaccine reverses morphine-induced immunosuppression and tumorigenesis

Although long-term use of morphine has been shown to promote tumor growth, the question whether tumorigenesis occurs as a result of an immunosuppressive effect remains to be investigated. In mice rendered tolerant to morphine, the efficacy and mechanism of a vaccination to rescue morphine-induced immunosuppression and prevent tumor growth was assessed both in vitro and in vivo. Herein, we found that morphine-injected mice exhibited higher tumor growth rates and lower percentages of CD8+ T lymphocytes. The mechanism of morphine suppression of immunity might be through the suppression of E7-specific CD8+ T lymphocyte proliferation and the promotion of apoptosis of these cells by the Bcl-2 and Bax pathways. The suppressive effect of E7-specific CD8+ T lymphocytes by morphine could be reversed by naloxone. We have previously shown that calreticulin linked with E7 (CRT/E7) could enhance the CD8+ T cell response and the anti-tumor effects (W. F. Cheng et al. (2001) J. Clin. Invest. 108, 669-678). CRT/E7 DNA vaccine could overcome the immunosuppressive effect of morphine and suppress tumor growth. Our findings reveal that long-term morphine treatment dose-dependently promotes tumor growth and a DNA vaccine may serve as a useful approach to treat the profound immunosuppressive function and prevent tumorigenesis after long-term morphine treatment.