SEARCH · PubMed Health

Results for “Mefenamic Acid”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 469 records · Page 26Linked to original sources

PubMed1980

Medicines of choice in low back pain.

The marketed formulations of 6 analgesic preparations were compared in the treatment of patients suffering from acute exacerbations of low back pain using a crossover trial of balanced incomplete block design. Sixty out-patients with symptoms resulting from a mechanical or degenerative condition were each prescribed 3 drugs which were administered consecutively for 1 week each. The medications (and daily dosages) were coded as A --aspirin (3600 mg), B --dextropropoxyphene plus paracetamol (260 mg plus 2600 mg), C --indomethacin (150 mg), D --mefenamic acid (1500 mg), E --paracetamol (4000 mg), and F --phenylbutazone (300 mg). Daily pain scores were significantly lower (p less than 0.05) during treatment D than during treatments E and B, and significantly lower (p less than 0.05) during treatment A than during treatment B. There were large and significant differences between treatments in the percentages of recommended doses acceptable to the patients and in the number of defaults from the prescribed regimens. The patients chose F and D significantly more (p less than 0.05) often than A. Overall, there were consistently superior performances by mefenamic acid and phenylbutazone with little to choose between the two.

Acetaminophen↗

PubMed2006

Interaction between inhibitors of inducible nitric oxide synthase and cyclooxygenase in adjuvant-induced arthritis in female albino rats: an isobolographic study.

We studied the interaction of S-methylisothiourea (a selective inducible nitric oxide synthase inhibitor) with rofecoxib (a selective cyclooxygenase-2 inhibitor) and mefenamic acid (a non-selective cyclooxygenase inhibitor) in adjuvant-induced arthritis in female albino Wistar rats, applying the isobolographic analysis. Each drug was effective in reducing the progressive increase in paw volume less than 50% except rofecoxib, when used alone. Log dose-response curve was obtained for each drug along with the corresponding ED(25). Following isobolographic analysis, combination of S-methylisothiourea with rofecoxib and mefenamic acid revealed supra-additive or synergistic interaction. Experimental ED(25) of the combinations was significantly lower than the theoretical ED(25) of the corresponding drug combination which substantiated the synergistic type of interaction between inducible nitric oxide synthase and cyclooxygenase in adjuvant-induced arthritis in female albino rats. Results suggest that NO regulates the cyclooxygenase enzyme activity as the activity of cyclooxygenase enzymes in the LPS-stimulated leukocyte lysates was significantly low or hardly detectable in the presence of varying concentrations of S-methylisothiourea. Simultaneous inhibition of inducible nitric oxide synthase and cyclooxygenase appears to offer an alternative approach for ameliorating the progression of arthritis.

Animals↗

PubMed2005

Interaction between inhibitors of inducible nitric oxide synthase and cyclooxygenase in Brewer's yeast induced pyrexia in mice: an isobolographic study.

We studied the interaction of S-methylisothiourea (a selective inducible nitric oxide synthase inhibitor) with rofecoxib (selective cyclooxygenase-2 inhibitor) and mefenamic acid (non-selective cyclooxygenase inhibitor) in Brewer's yeast-induced pyrexia in mice by isobolographic analysis. Each drug was effective in reducing pyrexia when used alone. Log-dose-response curves of all the three drugs did not show any significant departure from parallelism indicating thereby, a common mode of antipyretic action. However, rofecoxib exhibited significantly higher potency than S-methylisothiourea. Isobolographic analysis of combination of S-methylisothiourea with rofecoxib and mefenamic acid revealed additive interaction. Experimental ED(50) of the combinations was not significantly different from theoretical additive ED(50) of the corresponding drug combination, that substantiated the additive nature of interaction between inducible nitric oxide synthase and cyclooxygenase in Brewer's yeast-induced fever in mice. Results suggest involvement of a mediator that is subservient to both inducible nitric oxide synthase and cyclooxygenase-2 enzyme activities. For further investigation, peroxynitrite ion may be considered to be the putative mediator.

Animals↗

PubMed1986

Role of prostaglandins in marihuana-induced bronchodilation.

In vitro evidence suggests that physiological effects of marihuana may be mediated by prostaglandins via the stimulation of phospholipase A2. To verify if marihuana could act by this route in vivo, we tested the effects of acetylsalicylic and mefenamic acids, inhibitors of cyclooxygenase, on marihuana-induced bronchodilation and tachycardia. In 11 healthy volunteers, marihuana smoking (7 mg/kg, 1.7% delta 9-tetrahydrocannabinol) produced a significant increase in specific airway conductance (from 0.262 +/- 0.033 to 0.360 +/- 0.050 s-1 X cm H2O-1, mean +/- SE, p less than 0.01), forced expiratory volume in 1 s (4.02 +/- 0.22-4.27 +/- 0.25 liter, p less than 0.05) and heart rate (73.2 +/- 2.0-108.5 +/- 5.2 beats/min, p less than 0.001). In a second session, acetylsalicylic or mefenamic acid was taken for 30 h before marihuana smoking. No inhibition of marihuana-induced increase of specific airway conductance, forced expiratory volume in 1 s and heart rate was found. These findings suggest that the bronchodilation and the tachycardia induced by marihuana smoking in humans are not mediated by prostaglandins.

Adult↗

PubMed2001

Competition of tamoxifen with thyroxine for TBG binding: ligand binding assay and computational data.

OBJECTIVE: Tamoxifen, a nonesteroidal antiesterogen, is widely used in the treatment of breast cancer. Recently, the effect of tamoxifen on thyroid function has caused considerable concern, yet the results of different studies are controversial and the precise mechanism of such influence is obscure. In view of the fact that some drugs such as furosemide, diclofenac and mefenamic acid, based on the structural similarities to thyroxine could compete for binding to thyroxine binding globulin (TBG) and appears that there are some structural similarities between tamoxifen and thyroxine, one can hypothesize that tamoxifen is also able to compete for TBG binding and thereby affecting thyroid function tests. DESIGN AND METHODS: In this study, we designed an in vitro binding assay as well as computational methods using MOPAC 7 package for evaluation of competitive potency of tamoxifen for TBG binding in comparison with well-known TBG competitors (including furosemide, mefenamic acid and diclofenac). RESULTS: The result of competition assay and Scatchard analysis revealed that tamoxifen does not bind to TBG at the T4 binding site, thus it is not a thyroxine competitor. Computational results also indicated that structural characteristics of tamoxifen are significantly different from those of T4 and its well-known competitors. CONCLUSION: In conclusion, the probability of competition between tamoxifen and T4 is ruled out by these results.

Binding, Competitive↗

PubMed2000

Oral contraceptive pills for heavy menstrual bleeding.

BACKGROUND: Menorrhagia (heavy menstrual bleeding) is a benign yet debilitating social and health condition. The widely accepted clinical definition of menorrhagia is blood loss of 80ml or more per period. This figure is derived from population studies that have shown that the average blood loss is between 30 and 40ml, and 90% of women have blood losses of less than 80ml. Excessive menstrual bleeding is the commonest cause of iron deficiency in the United Kingdom affecting 20-25% of the fertile female population. Menorrhagia is a common problem accounting for 12% of all gynaecological referral in the UK. Ranges of medical therapies are prescribed in order to reduce excessive menstrual blood loss, including prostaglandin synthetase inhibitors, antifibrinolytics, the oral contraceptive pill and other hormones. The combined oral contraceptive pill (OCP) is claimed to have a variety of beneficial, inducing a regular shedding of a thinner endometrium and inhibiting ovulation thus having the effect of treating menorrhagia and providing contraception. OBJECTIVES: To determine whether: 1. the OCP is an effective medical therapy to reduce menorrhagia in both the short term and long term. 2. the effectiveness of combined oral contraceptive pills (OCP) compared with other medical therapies for the treatment of menorrhagia. 3. OCP is a more cost effective method than any other medical treatments of menorrhagia. 4. OCP has fewer side effects than other drugs used for menorrhagia. SEARCH STRATEGY: All publications which describe randomised trials of OCP for the treatment of menorrhagia were obtained using the search strategy developed by the Menstrual Disorders Group. SELECTION CRITERIA: All randomised controlled comparisons of OCP versus other medical therapies, placebo or no treatment for the treatment of menorrhagia. Women of reproductive years with regular heavy periods, measured either objectively or subjectively and greater than, or equal to, two months follow up. DATA COLLECTION AND ANALYSIS: All assessments of the quality of trials and data extraction were performed unblinded by at least two reviewers. Only one trial met the inclusion criteria and none were excluded. The included trial involved a total of 45 women. MAIN RESULTS: As the trial used a cross-over design, only data from the first treatment period (cycles 3 and 4 ) were analysed. The results from all the three mefanamic acid groups were combined. There was no significant difference in menstrual blood loss (MBL) between those patients treated with the OCP and danazol, mefenamic acid or naproxen. REVIEWER'S CONCLUSIONS: The one small study identified [Fraser 1991] found no significant difference between groups treated with OCP, mefenamic acid, low dose danazol or naproxen. Overall, the evidence from the one study identified [Fraser 1991] is not sufficient to adequately assess the effectiveness of OCP. This review was unable to achieve its stated objectives because of the paucity of the data.

Contraceptives, Oral↗

PubMed1988

Nimesulide. A preliminary review of its pharmacological properties and therapeutic efficacy in inflammation and pain states.

Nimesulide is a new non-steroidal anti-inflammatory analgesic agent given orally or rectally on a twice daily basis in a number of inflammatory and pain states. Although still at an early stage of clinical assessment, preliminary evidence suggests that nimesulide 200 to 400mg daily is significantly more effective than placebo in reducing the pain, fever and inflammatory symptoms of chronic rheumatoid arthritis or osteoarthritis, respiratory tract infections, otorhinolaryngological diseases, soft tissue and oral cavity inflammation, dysmenorrhoea, phlebitis/thrombosis, urogenital disease and postoperative pain states. In a number of comparative studies, nimesulide has also been shown to be more effective than piroxicam (in osteoarthritis), paracetamol (acetaminophen) [in respiratory tract inflammation], benzydamine or naproxen (in otorhinolaryngological disease), phenylprenazone (in laryngotracheitis/bronchitis, respiratory inflammation and otorhinolaryngological disease), Serratia peptidases (in postoperative or dental pain, trauma and phlebitis), ketoprofen (in postoperative dental pain) and mefenamic acid (in dysmenorrhoea). In addition, the efficacy of nimesulide has been observed to be comparable with that of aspirin, with or without vitamin C, and mefenamic acid (in respiratory tract infection), ibuprofen (in soft tissue disease), naproxen (in respiratory tract inflammation, dysmenorrhoea and postoperative pain states), suprofen and paracetamol (in postoperative pain states), benzydamine (in genitourinary tract inflammation) and dipyrone, paracetamol or diclofenac (in fever). The safety profile of nimesulide has yet to be fully established, although initial evidence suggests the usual adverse effects associated with non-steroidal anti-inflammatory drugs occur, possibly with a lower incidence of gastrointestinal problems than with other members in its therapeutic class. Nimesulide, therefore, appears to offer a useful alternative to other non-steroidal anti-inflammatory drugs in the treatment of patients with inflammatory conditions and/or pain and fever states. However, further definition of its efficacy and tolerability is clearly required, particularly in comparison with established or other new drugs in its therapeutic class.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1983

Reduction of enzyme release from reperfused ischemic hearts by steroidal and non-steroidal prostaglandin synthesis inhibitors.

Exacerbation of heart tissue damage by reperfusion of the ischemic myocardium is a well documented phenomenon. The present study was undertaken to evaluate prostaglandin (PG) involvement in reperfusion-induced damage of isolated globally ischemic rat hearts. Reperfusion produced significant increases in creatinephosphokinase (CPK) and lactic dehydrogenase (LDH) efflux which was accompanied by enhanced PG release. Three non-steroidal antiinflammatory drugs; indomethacin, mefenamic acid and ASA, and the steroidal agents; dexamethasone, hydrocortisone and methylprednisolone significantly reduced both the release of CPK and PGs upon reperfusion whereas only indomethacin and mefenamic acid decreased LDH release. There was a significant correlation between the inhibition of PG synthesis and the attenuation of CPK leakage by both non-steroidal (P less than 0.001) and steroidal (P = 0.02) antiinflammatory agents. In spite of beneficial effects on enzyme release, drug treatment did not enhance recovery of mechanical function after reperfusion. The results suggest that inhibition of PG biosynthesis may be beneficial in preserving membrane, particularly mitochondrial integrity of the reperfused myocardium.

Animals↗

PubMed1988

A possible role for prostaglandins in the expression of morphine dependence in guinea-pig isolated ileum.

1. The effects of the cyclo-oxygenase inhibitors, indomethacin (1.3 microM) and mefenamic acid (10 microM), were investigated on the naloxone-precipitated withdrawal contracture of the morphine-dependent guinea-pig ileum in vitro. 2. Both indomethacin and mefenamic acid prevented expression of the withdrawal contracture on naloxone challenge. 3. The effects of indomethacin were reversed by the concurrent application of a low dose of prostaglandin E1 (10 nM). 4. It was concluded that prostaglandins probably play a role in the expression of morphine withdrawal in this model.

Alprostadil↗

PubMed2003

Ibuprofen for the treatment of a patent ductus arteriosus in preterm and/or low birth weight infants.

BACKGROUND: A patent ductus arteriosus (PDA) complicates the clinical course of preterm infants, increasing their risks of developing chronic lung disease (CLD), necrotizing enterocolitis (NEC), and intraventricular hemorrhage (IVH). Indomethacin is used as standard therapy to close a PDA, but is associated with reduced blood flow to the brain, kidneys and gut. Ibuprofen, another cyclo-oxygenase inhibitor, may be as effective with fewer side effects. OBJECTIVES: To determine the effectiveness and safety of ibuprofen compared to placebo or no intervention for closing a PDA in preterm and/or low birth weight infants. To determine the effectiveness and safety of ibuprofen compared to other cyclo-oxygenase inhibitors (including indomethacin, mefenamic acid) for closing a PDA in preterm and/or low birth weight infants. SEARCH STRATEGY: Randomized (or quasi-randomized) controlled trials (RCTs) comparing ibuprofen to placebo or indomethacin or mefenamic acid for therapy of PDA were identified by searching the Cochrane Controlled Trials Register (Issue 4, 2002), MEDLINE (1996 - January 2003), CINAHL (1982 - November 2002), EMBASE (1980 - January 2002), reference lists of published RCTs and abstracts from the Pediatric Academic Societies and the European Society for Pediatric Research meetings published in Pediatric Research (1991 - 2002). No language restrictions were applied. SELECTION CRITERIA: 1) DESIGN: Randomized or quasi-randomized controlled trials 2) POPULATION: Preterm (< 37 weeks gestational age) or low birth weight infants (< 2500 grams) with a clinically or echocardiographically diagnosed PDA 3) INTERVENTION: Administration of ibuprofen for the closure of PDA 4) OUTCOMES: At least one of the following outcomes were reported: failure to close a PDA, mortality, surgical ligation, intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL), NEC, decreased urine output, retinopathy of prematurity (ROP), CLD, sepsis, days on supplementary oxygen. DATA COLLECTION AND ANALYSIS: At least two reviewers worked independently at each step of the review, then compared results and resolved differences. Methodological quality of eligible studies was assessed according to blinding of randomization, of intervention and of outcome assessment, and completeness of followup. Weighted treatment effects, calculated using Revman 4.1, included typical relative risk (RR), typical risk difference (RD), number needed to treat (NNT) or harm (NNH), and weighted mean difference (WMD), all with 95% confidence intervals (CI). A fixed effect model was used for meta-analyses. Heterogeneity tests were performed to assess the appropriateness of pooling the data. MAIN RESULTS: Eight studies including 509 patients were included. All studies compared the effectiveness of ibuprofen to indomethacin for the closure of a PDA. There was no statistically significant heterogeneity of treatment effect for any of the outcomes. For the primary outcome (failure of ductal closure), there was no statistically significant difference between ibuprofen and indomethacin groups [RR 0.92 (95% CI 0.69, 1.22)]. There were no statistically significant differences in mortality, surgical duct ligation, duration of ventilator support, IVH, PVL, NEC, time to full enteral feeds, ROP, sepsis, duration of hospital stay or gastrointestinal bleed. For many of these outcomes the sample size was small and the estimates imprecise. The incidence of decreased urine output (< 1cc/kg/hr) was lower in the ibuprofen group as compared to the indomethacin group [NNT 9 (95% CI 5-14)]. This was the only statistically significant clinical finding favouring ibuprofen. Chronic lung disease defined as oxygen requirement at 28 days post-natally was statistically significantly more likely to occur in the ibuprofen group [RR 1.37 (95% CI 1.01, 1.86); NNH 7 (95% CI 3 - 100)]. No studies comparing ibuprofen versus placebo for the closure of PDA were identified. REVIEWER'S CONCLUSIONS: We found no statistically significant difference in the effectiveness of ibuprofen compared to indomethacin in closing the PDA. Ibuprofen reduces the risk of oliguria. However, ibuprofen may increase the risk for chronic lung disease, and pulmonary hypertension has been observed in three infants after prophylactic use of ibuprofen. Based on currently available information ibuprofen does not appear to confer a net benefit over indomethacin for the treatment of a PDA. We conclude that indomethacin should remain the drug of choice for the treatment of a PDA. Future research may include a four arm trial where infants are randomized at birth, either to a prophylaxis arm starting at birth or to an arm in which treatment starts after a PDA is diagnosed by echocardiography within the first seven days of life. Within the prophylaxis and treatment arms, the infants would be randomized to either ibuprofen or indomethacin. The primary outcome should be intact survival (survival without handicap) at 18 months corrected age.

Cyclooxygenase Inhibitors↗

PubMedDate not supplied

[The hepatotropic properties of nonsteroidal anti-inflammatory agents].

The hepatotropic effect of nonsteroidal anti-inflammatory drugs (NSAID) such as indomethacin, voltaren, piroxicam, phenylbutazon, mefenamic acid was studied. It was found that according to their level of the pharmacological protection of the liver against tetrachlormethan these agents may be arranged in the following sequence: mefenamic acid, phenylbutazon, voltaren, piroxicam. The hepatoprotective effect of NSAID correlates with the antioxidant properties and fails to correlate with the antioxidant ones. The hepatotoxic effect of NSAID was determined by their ability to suppress synthesis of prostaglandins.

Animals↗

PubMed2005

Occurrence and fate of anti-inflammatory drugs in wastewater treatment plants in Japan.

The fates of anti-inflammatory drugs (e.g., ibuprofen, naproxen, mefenamic acid and ketoprofen), which are frequently detected in the discharges of wastewater treatment plants (WWTPs) and river water in Japan, were clarified in two WWTPs. The concentrations of ibuprofen, naproxen, mefenamic acid and ketoprofen were 69-1080, 179-305, 143-1580 and 160-1060 ng/L in the influent, and N.D. (< 40 ng/L), 74-166, 72-265, 64-107 ng/L in the effluent, respectively. The concentrations of the anti-inflammatory drugs analyzed were almost equal to or lower than those reported in foreign countries. High removal efficiencies of the drugs, except ibuprofen, were observed in the WWTP that has longer hydraulic retention time than that of the other WWTP. For ibuprofen, high removal efficiencies were observed in both WWTPs (84 to 98%). Disinfection by chlorination was not effective to remove the drugs surveyed. On the other hand, the effective removal of ketoprofen by ultraviolet (UV) radiation for disinfection was demonstrated, although the disinfection by-products were not identified.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1987

Inhibition by nonsteroidal anti-inflammatory drugs of superoxide production and granule enzyme release by polymorphonuclear leukocytes stimulated with immune complexes or formyl-methionyl-leucyl-phenylalanine.

The effects of nonsteroidal anti-inflammatory agents on superoxide production and granule enzyme release by human polymorphonuclear leukocytes stimulated with either formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe] or immune complexes were investigated. Cytochrome c reduction and the release of lysozyme, beta-glucuronidase, myeloperoxidase and gelatinase were measured. Auranofin, phenylbutazone, sulfasalazine and the phospholipase A2 inhibitor, 4-bromophenacyl bromide, strongly inhibited these responses in fMet-Leu-Phe stimulated cells, at concentrations below 50 microM. Indomethacin, piroxicam, mefenamic acid, primaquine and quinacrine at 50-250 microM were inhibitory. Up to 1 mM ibuprofen and chloroquine inhibited superoxide production but had little effect on degranulation. With cells stimulated by IgG aggregates (immune complexes), up to 1 mM ibuprofen, mefenamic acid and piroxicam did not inhibit either response. Indomethacin, phenylbutazone, sulfasalazine and primaquine inhibited, but considerably higher concentrations were required than with fMet-Leu-Phe. Quinacrine inhibited superoxide production equally well with both stimuli but inhibited enzyme release only with fMet-Leu-Phe. Only auranofin, 4-bromophenacyl bromide, and the weakly effective chloroquine exerted approximately the same effect with both stimuli. D-Penicillamine did not affect enzyme release with either stimulus and interfered in the superoxide assay. Gelatinase release induced by fMet-Leu-Phe was affected to the same extent, or slightly more, than release of the other granule enzymes. With immune complexes, there was only modest inhibition of gelatinase release by any of the drugs at 250-1000 microM. Our results reinforce previous observations that many anti-inflammatory drugs affect neutrophil functions, but their effects vary with stimulus. The relative insensitivity of immune complex-induced responses to most of the drugs must be taken into account when considering their mode of action.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1996

Mechanism of alpha-2 adrenergic modulation of canine cardiac Purkinje action potential.

We reported recently that stimulation of postjunctional alpha-2 adrenergic receptors prolongs the action potential durations (APD) of isolated canine Purkinje fibers. With standard microelectrode techniques, we examined the ionic mechanism through which alpha-2 adrenergic stimulation prolonged Purkinje APD, by measuring the effects of inhibitors of the various plateau currents on the alpha-2-mediated prolongation of APD. The alpha-2-specific agonist UK 14,304 (0.1 microM) prolonged the Purkinje APD at 50% repolarization and the APD at 90% repolarization, and these effects were inhibited by yohimbine (0.1 microM). The Purkinje APD at 50% repolarization and the APD at 90% repolarization were prolonged significantly with the transient outward potassium current inhibitor 4-aminopyridine (1 mM), the rapid component of delayed rectifier potassium current inhibitor d-sotalol (10 microM), the slow component of delayed rectifier potassium current inhibitor indapamide (0.1 microM) and the chloride current inhibitor mefenamic acid (10 nM) and were shortened significantly with the calcium current inhibitor nifedipine (0.3 microM). Prolongation of Purkinje APD at 50% repolarization and APD at 90% repolarization by UK 14,304 remained intact in the presence of d-sotalol, indapamide, mefenamic acid and nifedipine. All of these UK 14,304 effects were significantly reversed by yohimbine. Only in the presence of 4-aminopyridine did UK 14,304 fail to prolong Purkinje APD. The phase 1 magnitudes of Purkinje action potentials were also significantly inhibited by UK 14,304. This effect was completely abolished only in the presence of 4-aminopyridine. These results suggest that inhibition of the 4-aminopyridine-sensitive transient outward potassium current is the major ionic mechanism by which alpha-2 adrenergic stimulation prolongs Purkinje APD.

Action Potentials↗

PubMed1984

pH-induced difference spectrophotometric methods for drug analysis. Part 2: Determination of mefenamic and flufenamic acid.

On the basis of the spectral changes induced by changing the solvent medium from HCl (0.01 mol . l-1) to NaOH (0.01 mol . l-1), coefficient-difference spectrophotometric methods using the six-points quadratic order of the orthogonal polynomials have been developed. The optimum wavelength ranges were 326 to 386 nm for mefenamic acid and 322 to 382 nm for flufenamic acid, both measured at 12 nm intervals. The respective mean percentage recoveries were 100.1 +/- 0.89 over a concentration range of 0.6-2.6 mg/100 ml of mefenamic acid and 100.7 +/- 0.61 over a range of 0.2-2.4 mg/100 ml for flufenamic acid (p = 0.05). Both methods gave precise results with relative standard deviation less than 1%. Trials to adapt single wavelength difference technique as well as the cubic order of the orthogonal polynomials were also performed; their results were discussed on a statistical basis. The developed procedures have been applied to the analysis of some randomly collected market preparations and the results obtained proved suitability for application in routine analysis.

Capsules↗

PubMed1999

The GC/MS analysis of some commonly used non-steriodal anti-inflammatory drugs (NSAIDs) in pharmaceutical dosage forms and in urine.

All the commonly used non-steriodal anti-inflammatory drugs (NSAIDs), except mefenamic acid, when extracted from the pharmaceutical dosage forms or the urines of users, and derivatized by silylation and then analysed by GC/MS, gave the mono- or the di-trimethylsilyl derivatives (depending on the number of derivatized groups in the drug) as the sole products. Mefenamic acid gave a mixture of products. When extracted from pharmaceutical dosage froms or from the urines of users, and analysed by GC/MS without derivatization, some of the NSAIDs were separated and detected as the unchanged molecules as the sole products, while others were separated and detected in altered forms as sole products or mixtures, depending on: (a) the solvent in which the extract was dissolved for injection into GC/MS, (b) the chemical structure of the drug, and (c) specifically for diflunisal, the presence or absence of potential methylating and/or acetylating agents on the GC column and/or septum. The main thermally-induced reactions of the underivatized NSAIDs included (i) methyl ester formation at the COOH group when the extract was dissolved in methanol, (ii) decarboxylation (i.e., loss of CO2), (iii) dehydration (i.e., loss of H2O) when the chemical structure permitted, such as for diclofenac, and (iv) cleavage at a carbon-heterocyclic nitrogen bond when one is present in an NSAID. Heating the urine in approximately 2 M HCl at 100 degrees C for 30 min, has been found to be a satisfactory means for effecting hydrolysis of the NSAIDs glucuronide conjugates. No metabolites, resulting from aromatic-ring hydroxylation, have been detected in urine for any of the NSAIDs studied.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1994

Involvement of nitric oxide and cyclooxygenase products in photoactivation-induced microvascular occlusion.

Photoactivation of intravascular dyes with high doses of light is a technique used clinically to treat tumors. This procedure results in arteriolar constriction, mast cell degranulation, platelet thrombus formation, and, ultimately, microvascular stasis. In vivo microscopy was utilized in the current study to examine if the endothelial release of prostaglandins and nitric oxide could participate in the microvascular effects of photoactivation. Diameter changes and thrombus formation of arterioles and venules of the cremaster muscle of male Sprague-Dawley rats were quantitated during continuous light activation of intravascular fluorescein isothiocyanate conjugated to bovine serum albumin. Vasoconstriction and thrombus development were assessed separately, using the relationships between the width of the red blood cell column, the inner wall diameter, and the thickness of the plasma layer. Venular photoactivation resulted in thrombus growth which reached 30% of the maximum size by 16.8 +/- 3.71 min and a subsequent growth rate of 6.2 +/- 1.64 microns/min. In arterioles, 30% thrombus growth occurred at 14.0 +/- 2.02 min with a growth rate of 3.0 +/- 0.57 microns/min. Continuous arteriolar photoactivation led to a vasoconstriction of 34.4 +/- 6.87% of the initial vessel diameter. Thirty percent of the maximal constriction occurred after 10.6 +/- 1.26 min of photoactivation. Constriction proceeded at a rate of 3.8 +/- 1.32 microns/min. Topically applied mefenamic acid (a cyclooxygenase inhibitor) and Nw-nitro-L-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor) each enhanced both the arteriolar and the venular thrombus growth due to photoactivation. Photoactivation-induced arteriolar constriction was augmented by L-NAME and inhibited by mefenamic acid. These data suggest that the photoactivation of intravascular dyes is accompanied both by the release of nitric oxide, which inhibits thrombus development and arteriolar constriction, and by the release of cyclooxygenase products, which inhibit thrombus growth and induce vasoconstriction. Rats treated with busulfan to induce thrombocytopenia exhibited a 90% decrease in circulating platelets. In these animals, photoactivation caused significantly delayed thrombus growth in arterioles and venules, while arteriolar constriction remained unaltered, suggesting that the vasoconstrictor prostanoid is not of platelet origin.

Amino Acid Oxidoreductases↗

PubMed1995

Spasmolytic and calmodulin inhibitory effect of non-steroidal anti-inflammatory drugs in vitro.

The effect of several anti-inflammatory drugs (NSAIDs), the calmodulin inhibitor W-7 and cortisol on vanadate-induced tonic contraction and on calmodulin dependent cAMP-phosphodiesterase activity have been assayed. Indomethacin, diclofenac, phenylbutazone, mefenamic acid, naproxen, tolmetin, piroxicam, aspirin and W-7, but not metimazol, produce dose-dependent relaxation of vanadate-induced tonic contraction on isolated rat uterus. Cortisol relaxes the vanadate contraction up to 45%. None of the drugs assayed inhibit the basal activity of phosphodiesterase with concentrations lower than 1 mM. However, indomethacin, diclofenac, phenylbutazone, mefenamic acid, naproxen, piroxicam, aspirin and W-7 inhibit, in a concentration-dependent way, the calmodulin-stimulated activity of phosphodiesterase. The maximum inhibition achieved with tolmetin (1 mM) and cortisol (1 mM) was 38% and 24%, respectively. Metamizol has no effect on basal or/and stimulated phosphodiesterase. This, as far as we know, is the first description of relationship between NSAIDs and calmodulin-dependent processes and our results suggest that the inhibition of calmodulin with NSAIDs may be directly related to their pKa and liposolubility.

3',5'-Cyclic-AMP Phosphodiesterases↗