Prostaglandin-mediated control of rat brain kynurenic acid synthesis – opposite actions by COX-1 and COX-2 isoforms

Summary. Kynurenic acid (KYNA), an endogenous glutamate-receptor antagonist preferentially blocking NMDA-receptors, has analgesic properties and has also been implicated in the pathophysiology of schizophrenia. Recently, the non-steroid anti-inflammatory drug (NSAID) diclofenac was found to increase rat brain KYNA. Here, we analyze whether cyclooxygenase (COX)-1 or COX-2 modulate the levels of rat brain KYNA. The non-selective COX-inhibitor diclofenac (50mg/kg, i.p.) or indomethacin (50mg/kg, i.p.), a non-selective inhibitor with a preferential selectivity for COX-1, produced an elevation in brain KYNA. In contrast, the COX-2 selective inhibitors parecoxib (25mg/kg, i.p.) or meloxicam (5mg/kg, i.p.) decreased brain KYNA. Both elevation and lowering of brain KYNA by indomethacin or parecoxib, respectively, were prevented by the prostaglandin E₁/E₂ agonist misoprostol (1mg/kg, s.c.). It is proposed that increased brain KYNA formation induced by NSAIDs displaying an inhibitory action on COX-1 contribute to their analgesic efficacy as well as to their psychiatric side effects.     

Propacetamol and diclofenac alone and in combination for analgesia after elective tonsillectomy

BACKGROUND: Diclofenac and paracetamol have different mechanisms and sites of action. Therefore, we tested if their combination is more effective for analgesia after tonsillectomy than either drug alone with respect to rescue analgesic consumption and visual analog scale values. METHODS: The analgesic effects of intravenously administered propacetamol (injectable pro-drug of paracetamol) and diclofenac or a combination on postoperative pain were compared in 71 adult elective tonsillectomy patients in a randomized, double-blind study. After induction of anesthesia the patients received monotherapy with 2 g propacetamol (n = 25) or 75 mg diclofenac (n = 25), or a combined treatment with 2 g propacetamol and 75 mg diclofenac (n = 21) in physiologic saline as an infusion. Postoperatively the propacetamol dosage was repeated twice and diclofenac once on the ward. Oxycodone (0.03 mg kg(-1)) was used as a rescue analgesic by patient-controlled analgesia. RESULTS: On average the patients needed oxycodone 15.3, 13.2 and 10.6 times in the propacetamol, diclofenac and combination groups, respectively (NS). A verbal rating scale and a visual analog scale were employed for assessing post-tonsillectomy pain, nausea and patient satisfaction in all groups. No statistically significant differences were found between the groups. Twelve of the 25 (48%) patients having received propacetamol complained of pain at the cannulation site. CONCLUSION: Combined treatment with propacetamol and diclofenac with the dosages used provided clinically only a minor advantage over monotherapy with propacetamol or diclofenac with respect to postoperative analgesia or the incidence of side-effects in adult tonsillectomy patients.     

Comparison of the effect of diclofenac with hyoscine-N-butylbromide in the symptomatic treatment of acute biliary colic

BACKGROUND: Although non-steroidal anti-inflammatory drugs (NSAID) and spasmolytics have been used to relieve biliary colic, the role of these drugs in the natural history of biliary colic has not been clarified. The objective of the present study is to compare the efficacy of intramuscular diclofenac with intramuscular hyoscine in the treatment of pain of acute biliary colic, and to study their role in the natural history of biliary colic and in the prevention of cholelithiasis-related complications. METHODS: Seventy-two consecutive patients with biliary colic were enrolled in this prospective, randomized, double-blind study. They received either a single 75 mg intramuscular dose of diclofenac (n = 36) or similarly administered 20 mg of hyoscine (n = 36). Pain severity was recorded on a visual analogue scale 30 min, 1 h, 2 h and 4 h after injection of the drug. Patients were then followed closely for the next 72 h for persistence or relapse of pain, or development of acute cholecystitis, or drug related complications. RESULTS: Diclofenac provided much more rapid relief of pain than hyoscine, as shown by significantly lesser pain scores after injection of the drug. 91.7% of patients on diclofenac were completely relieved of pain at 4 h as compared to 69.4% with hyoscine (P = 0.037). Progression to acute cholecystitis was seen in only 16.66% of patients on diclofenac as compared to 52.77% on hyoscine (P = 0.003). CONCLUSIONS: In patients with biliary colic, diclofenac gives much faster and more effective pain relief in a significantly larger number of patients as compared with hyoscine. Most remarkably, diclofenac can prevent progression of biliary colic to acute cholecystitis in a significant number of patients.     

Pharmacokinetics of oral diclofenac and acetaminophen in children after surgery

BACKGROUND: Our aim was to study the pharmacokinetics and pain scores following administration of single oral doses of either diclofenac or high-dose acetaminophen (paracetamol). METHODS: In the morning, the day after tonsillectomy, children 5-15 years of age were randomized in a double-blind manner to receive either diclofenac 1-2 mg.kg-1 (n=11) or acetaminophen 22.5 mg.kg-1 (n=10). Postoperative pain was assessed by self-report and blood samples were drawn every 30 min for 4 h after medication. RESULTS: Large interindividual differences in maximum plasma diclofenac concentrations (Cmax) were found. Mean Cmax was 2.4+/-1.3 microg.ml-1 and mean tmax was 2+/-0.5 h. No significant reduction in pain score with diclofenac was seen at any of the assessments during the study period. Eight of 10 children achieved Cmax of acetaminophen within the 10-20 microg.ml-1 antipyretic range. Mean tabs was 0.7+/-0.3 h and mean Cmax and tmax were 12.7+/-3.8 microg ml-1 and 1.4+/-0.5 h, respectively. No significant reduction in pain score with acetaminophen was seen at any of the assessments during the study period. CONCLUSIONS: The achieved concentrations of diclofenac and acetaminophen were not able to significantly reduce the children's pain score during the 5 h postingestion study period. Analgesic plasma acetaminophen concentrations may be higher than those required for antipyresis.     

Immune hemolytic anemia caused by sensitivity to a metabolite of etodolac, a nonsteroidal anti-inflammatory drug

BACKGROUND: Immune hemolytic anemia can be caused by sensitivity to many different drugs. In some instances, the sensitizing compound can be identified by in vitro testing, but results are often negative. One reason for this is that a drug metabolite formed in vivo can be the sensitizing agent, but the responsible metabolites have rarely been identified at a chemical level. This report describes a patient who developed severe, Coombs-positive hemolytic anemia on two occasions after taking the nonsteroidal anti-inflammatory drug etodolac. Studies were performed to characterize etodolac metabolites to which this patient was sensitive. CASE REPORT: Serum was tested for antibody in the presence and absence of drug using conventional methods and urine from individuals taking etodolac as a source of drug metabolites. Urinary metabolites of etodolac were identified by high-pressure liquid chromatography analysis. Glucuronide conjugates of etodolac and the 6-OH metabolite of etodolac were synthesized in a rat liver microsomal system to obtain reference standards. RESULTS: The patient's serum gave only trace (+/-) reactions with normal RBCs in the presence of etodolac but reacted strongly (4+) in the presence of urine from an individual taking this drug. The active urinary metabolites were identified as etodolac glucuronide and 6-OH etodolac glucuronide. CONCLUSION: This patient appears to have experienced acute, severe immune hemolytic anemia on two occasions because of sensitivity to the glucuronides of etodolac and 6-OH etodolac. In patients suspected of having drug-induced immune hemolytic anemia, RBC-reactive antibodies can sometimes be detected by using urine from an individual taking the implicated medication as the source of drug metabolites in in vitro reactions. For patients who present with acute immune hemolysis, a careful history of drug exposure should be taken, and, where indicated, confirmatory testing should be performed to identify the sensitizing drug and prevent inadvertent reinduction of hemolysis at a later time.     

双氯芬酸选择性抑制表达环氧合酶-2的肝癌细胞的增殖

 目的检测体外培养的人肝细胞癌HepG2,Hep3B细胞和正常肝细胞系QSG7701细胞内环氧酶-2(cyclooxygenase-2,COX-2)的表达,观察环氧酶抑制剂双氯芬酸(diclofenac)对上述细胞增殖的作用,并检测前列腺素E₂(PGE₂)对双氯芬酸作用的影响,以探讨双氯芬酸抗增殖作用与细胞内COX-2的关系。方法采用半定量逆转录聚合酶链反应(RT-PCR)检测COX-2 mRNA的表达水平,免疫印迹技术检测细胞内蛋白水平,cellcounting kit-8(CCK-8)细胞计数法测定细胞增殖活性。结果肝细胞癌HepG2和Hep3B细胞均高表达COX-2 mRNA和COX-2蛋白,正常肝细胞系QSG7701微弱表达COX-2。10～200μmol·L^-1的双氯芬酸浓度依赖性地抑制HepG2和Hep3B细胞的增殖(P<0.01),作用72h的半数抑制浓度(IC₅₀)分别为76.41和35.21μmol·L^-1。双氯芬酸对QSG7701的抑制作用较弱,IC₅₀值为170.23μmol·L^-1。20μmol·L^-1 PGE2与50μmol·L^-1双氯芬酸共同孵育能显著削弱后者抗HepG2和Hep3B细胞增殖的作用(P<0.01)。结论双氯芬酸通过抑制COX-2活性和PGE₂的生成,特异性地抑制表达COX-2的肝癌细胞的增殖。     

双氯灭痛钠对兔眼损伤性瞳孔缩小的作用

目的:评价0.1%双氯灭痛钠(DFNA)滴眼液和0.1%地塞米松磷酸钠(DeX)滴眼液对兔眼损伤性瞳孔缩小的抑制作用.方法:新西兰白兔6O只,随机分成实验对照组.O.1?NA或0.1?X术前术后用药组及仅术后用药组;手术显微镜下刀片开3mm长角膜,并缝合一针.术前及术后1h分别测角膜直径.结果:兔眼角膜损伤后能导致瞳孔缩小,0.1?NA或0.1?X均能抑制瞳孔缩小,和实验对照组比较,前者有非常显著性差异(P<0.01),后者无差异(P>0.5).结论:0.1?NA滴眼液能抑制兔眼损伤性瞳孔缩小.     

双氯芬酸钠搽剂的研制

对双氯芬酸钠搽剂的处方、工艺、质量标准、稳定性等内容进行了实验,结果表明符合搽剂要求,工艺、质量标准可行,药物稳定性好     

新型双氯芬酸钠缓释片的人体相对生物利用度研究

８名健康男性志愿者单剂量交叉口服１００ｍｇ受试双氯芬酸钠缓释片、扶他林或ＶｏｌｔａｒｅｎＳＲ１００后,Ｔｍａｘ分别为２．４±１．０、２．１±０．５和４．４±１．８ｈ;Ｃｍａｘ分别为６０２．６±９２．８、３３３７．６±１０８８．２　７６１．０±３４２．０ｎｇ／ｍｌ;ＭＲＴ分别为１３．２±４．８、２．９±０．８和７．９±１．９ｈ;ＡＵＣ０分别为４８６６．２±６４４．６、５３１４．３±５３４．３和４８２９．１±５８２．８ｎｇ／（ｍｌ－１·ｈ）;双氯芬酸钠缓释片和ＶｏｌｔａｒｅｎＳＲ１００相对于扶他林的生物利用度分别为８８．３±１３．２％和８６．３±１２．６％。另８名志愿者交叉口服受试双氯芬酸钠缓释片（１００ｍｇ,ｐｄ）和扶他林（５０ｍｇ,ｂｉｄ〕,连服５天。Ｃｍａｘ分别为５９３．９±１３４．１、１２４７．８±５２７．５ｎｇ／ｍｌ,峰谷波动率（ＰＴＦ）分别为３．３±１．２、５．３±２．１。本研究将为新型双氯芬酸钠缓释片的临床应用提供依据。     

樟脑对烟酰胺和双氯芬酸钠透皮吸收作用的研究

目的：研究樟脑对烟酰胺和双氯芬酸钠透皮吸收的影响,并与月桂氮苷卓酮的作用进行比较。方法：用两室扩散池体外透皮实验装置,以兔皮为屏障,使用不同浓度的樟脑,分别测定烟酰胺和双氯芬酸钠的透皮百分率。结果：１ ％ 樟脑对烟酰胺没有促皮渗透作用,３ ％ 樟脑对烟酰胺和双氯芬酸钠有促皮渗透作用。结论：樟脑对烟酰胺和双氯芬酸钠均有促皮渗透作用,但作用弱于月桂氮苷卓酮,两药合用时不具有协同作用。