Determination of indomethacin and mefenamic acid in plasma by high-performance liquid chromatography

Design and application of potentiometric sensors for the determination of mefenamic and phenylanthranilic acids

Characteristics, performance and applications of potentiometric membrane sensors are described for the determination of mefenamic and phenylanthranilic ions. Ion associates of mefenamic, ClO₄^-, and phenylanthranilic ions with crystal violet (counter-cation) as ion exchange sites have been used as ionophores in the plasticized one- and two-layer membrane ion-selective electrodes. The LOD is reported to be 8.4 × 10^-5 M for mefenamic acid, and 5.1 × 10^-5 M for phenylanthranilic acid. The cations of basic dyes (crystal violet) are characterized by significant delocalization of the positive charge and polarizability. This may explain the better selectivity of the developed sensors. These sensors were used for the direct assay of mefenamic and N-phenylanthranilic acids in model solutions and applications studied in commercial pharmaceutical preparations.

Ibuprofen for the treatment of patent ductus arteriosus in preterm or low birth weight (or both) infants

BACKGROUND

Indomethacin is used as standard therapy to close a patent ductus arteriosus (PDA) but is associated with reduced blood flow to several organs. Ibuprofen, another cyclo-oxygenase inhibitor, may be as effective as indomethacin with fewer adverse effects.

OBJECTIVES

To determine the effectiveness and safety of ibuprofen compared with indomethacin, other cyclo-oxygenase inhibitor(s), placebo, or no intervention for closing a patent ductus arteriosus in preterm, low-birth-weight, or preterm and low-birth-weight infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 10), MEDLINE via PubMed (1966 to 30 November 2017), Embase (1980 to 30 November 2017), and CINAHL (1982 to 30 November 2017). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of ibuprofen for the treatment of a PDA in preterm, low birth weight, or both preterm and low-birth-weight newborn infants.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of the Cochrane Neonatal Review Group. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included 39 studies enrolling 2843 infants. Ibuprofen (IV) versus placebo: IV Ibuprofen (3 doses) reduced the failure to close a PDA compared with placebo (typical relative risk (RR); 0.62 (95% CI 0.44 to 0.86); typical risk difference (RD); -0.18 (95% CI -0.30 to -0.06); NNTB 6 (95% CI 3 to 17); I² = 65% for RR and I² = 0% for RD; 2 studies, 206 infants; moderate-quality the evidence). One study reported decreased failure to close a PDA after single or three doses of oral ibuprofen compared with placebo (64 infants; RR 0.26, 95% CI 0.11 to 0.62; RD -0.44, 95% CI -0.65 to -0.23; NNTB 2, 95% CI 2 to 4; I² test not applicable). Ibuprofen (IV or oral) compared with indomethacin (IV or oral): Twenty-four studies (1590 infants) comparing ibuprofen (IV or oral) with indomethacin (IV or oral) found no significant differences in failure rates for PDA closure (typical RR 1.07, 95% CI 0.92 to 1.24; typical RD 0.02, 95% CI -0.02 to 0.06; I² = 0% for both RR and RD; moderate-quality evidence). A reduction in NEC (necrotising enterocolitis) was noted in the ibuprofen (IV or oral) group (18 studies, 1292 infants; typical RR 0.68, 95% CI 0.49 to 0.94; typical RD -0.04, 95% CI -0.07 to -0.01; NNTB 25, 95% CI 14 to 100; I² = 0% for both RR and RD; moderate-quality evidence). There was a statistically significant reduction in the proportion of infants with oliguria in the ibuprofen group (6 studies, 576 infants; typical RR 0.28, 95% CI 0.14 to 0.54; typical RD -0.09, 95% CI -0.14 to -0.05; NNTB 11, 95% CI 7 to 20; I² = 24% for RR and I² = 69% for RD; moderate-quality evidence). The serum/plasma creatinine levels 72 hours after initiation of treatment were statistically significantly lower in the ibuprofen group (11 studies, 918 infants; MD -8.12 µmol/L, 95% CI -10.81 to -5.43). For this comparison, there was high between-study heterogeneity (I² = 83%) and low-quality evidence. Ibuprofen (oral) compared with indomethacin (IV or oral): Eight studies (272 infants) reported on failure rates for PDA closure in a subgroup of the above studies comparing oral ibuprofen with indomethacin (IV or oral). There was no significant difference between the groups (typical RR 0.96, 95% CI 0.73 to 1.27; typical RD -0.01, 95% CI -0.12 to 0.09; I² = 0% for both RR and RD). The risk of NEC was reduced with oral ibuprofen compared with indomethacin (IV or oral) (7 studies, 249 infants; typical RR 0.41, 95% CI 0.23 to 0.73; typical RD -0.13, 95% CI -0.22 to -0.05; NNTB 8, 95% CI 5 to 20; I² = 0% for both RR and RD). There was low-quality evidence for these two outcomes. There was a decreased risk of failure to close a PDA with oral ibuprofen compared with IV ibuprofen (5 studies, 406 infants; typical RR 0.38, 95% CI 0.26 to 0.56; typical RD -0.22, 95% CI -0.31 to -0.14; NNTB 5, 95% CI 3 to 7; moderate-quality evidence). There was a decreased risk of failure to close a PDA with high-dose versus standard-dose of IV ibuprofen (3 studies 190 infants; typical RR 0.37, 95% CI 0.22 to 0.61; typical RD - 0.26, 95% CI -0.38 to -0.15; NNTB 4, 95% CI 3 to 7); I² = 4% for RR and 0% for RD); moderate-quality evidence). Early versus expectant administration of IV ibuprofen, echocardiographically-guided IV ibuprofen treatment versus standard IV ibuprofen treatment, continuous infusion of ibuprofen versus intermittent boluses of ibuprofen, and rectal ibuprofen versus oral ibuprofen were studied in too few trials to allow for precise estimates of any clinical outcomes.

AUTHORS' CONCLUSIONS

Ibuprofen is as effective as indomethacin in closing a PDA. Ibuprofen reduces the risk of NEC and transient renal insufficiency. Therefore, of these two drugs, ibuprofen appears to be the drug of choice. The effectiveness of ibuprofen versus paracetamol is assessed in a separate review. Oro-gastric administration of ibuprofen appears as effective as IV administration. To make further recommendations, studies are needed to assess the effectiveness of high-dose versus standard-dose ibuprofen, early versus expectant administration of ibuprofen, echocardiographically-guided versus standard IV ibuprofen, and continuous infusion versus intermittent boluses of ibuprofen. Studies are lacking evaluating the effect of ibuprofen on longer-term outcomes in infants with PDA.

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

BACKGROUND

Patent ductus arteriosus (PDA) complicates the clinical course of preterm infants and increases the risk of adverse outcomes. Indomethacin has been the standard treatment to close a PDA but is associated with renal, gastrointestinal, and cerebral side effects. Ibuprofen has less effect on blood flow velocity to important organs.

OBJECTIVES

Primary objectives To determine the effectiveness and safety of ibuprofen compared to placebo/no intervention, or other cyclo-oxygenase inhibitor drugs in the prevention of PDA in preterm infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 10), MEDLINE via PubMed (1966 to 17 October 2018), Embase (1980 to 17 October 2018), and CINAHL; 1982 to 17 October 2018). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing ibuprofen with placebo/no intervention or other cyclo-oxygenase inhibitor drugs to prevent PDA in preterm or low birth weight infants.

DATA COLLECTION AND ANALYSIS

We extracted outcomes data including presence of PDA on day three or four of life (after 72 hours of treatment), need for surgical ligation or rescue treatment with cyclo-oxygenase inhibitors, mortality, cerebral, renal, pulmonary, and gastrointestinal complications. We performed meta-analyses and reported treatment estimates as typical mean difference (MD), risk ratio (RR), risk difference (RD) and, if statistically significant, number needed to treat to benefit (NNTB) or to harm (NNTH), along with their 95% confidence intervals (CI). We assessed between-study heterogeneity by the I-squared test (I²). We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

In this updated analysis, we included nine trials (N = 1070 infants) comparing prophylactic ibuprofen (IV or oral) with placebo/no intervention or indomethacin. Ibuprofen (IV or oral) probably decreases the risk of PDA on day 3 or 4 (typical RR 0.39, 95% CI 0.31 to 0.48; typical RD -0.26, 95% CI -0.31 to -0.21; NNTB 4, 95% CI 3 to 5; 9 trials; N = 1029) (moderate-quality evidence). In the control group, the spontaneous closure rate was 58% by day 3 to 4 of age. In addition, ibuprofen probably decreases the need for rescue treatment with cyclo-oxygenase inhibitors (typical RR 0.17, 95% CI 0.11 to 0.26; typical RD -0.27, 95% CI -0.32 to -0.22; NNTB 4; 95% CI 3 to 5),and the need for surgical ductal ligation (typical RR 0.46, 95% CI 0.22 to 0.96; typical RD -0.03, 95% CI -0.05 to -0.00; NNTB 33, 95% CI 20 to infinity; 7 trials; N = 925) (moderate-quality evidence). There was a possible decrease in the risk of grade 3 or 4 intraventricular haemorrhage (IVH) in infants receiving prophylactic ibuprofen (typical RR 0.67, 95% CI 0.45 to 1.00; I² = 34%; typical RD -0.04, 95% CI -0.08 to- 0.00; I² = 60%; 7 trials; N = 925) (moderate-quality evidence). High quality evidence showed increased risk for oliguria (typical RR 1.45, 95% CI 1.04 to 2.02; typical RD 0.06, 95% CI 0.01 to 0.11; NNTH 17, 95% CI 9 to 100; 4 trials; N = 747). Low quality results from four studies (N = 202) showed that administering oral ibuprofen may decrease the risk of PDA (typical RR 0.47, 95% CI 0.30 to 0.74) and may increase risk of gastrointestinal bleeding (NNTH 7, 95% CI 4 to 25). No evidence of a difference was identified for mortality, any intraventricular haemorrhage (IVH), or chronic lung disease.

AUTHORS' CONCLUSIONS

This review shows that prophylactic use of ibuprofen, compared to placebo or no intervention, probably decreases the incidence of patent ductus arteriosus, the need for rescue treatment with cyclo-oxygenase inhibitors, and for surgical ductal closure. Adverse effects associated with ibuprofen (IV or oral) included increased risks for oliguria, increase in serum creatinine levels, and increased risk of gastrointestinal haemorrhage. There was a reduced risk for intraventricular haemorrhage (grade III - IV) but no evidence of a difference in mortality, chronic lung disease, necrotising enterocolitis, or time to reach full feeds. In the control group, the patent ductus arteriosus had closed spontaneously by day 3 or 4 in 58% of neonates. Prophylactic treatment exposes a large proportion of infants unnecessarily to a drug that has important side effects without conferring any important short-term benefits. Current evidence does not support the use of ibuprofen for prevention of patent ductus arteriosus. Until long-term follow-up results of the trials included in this review have been published, no further trials of prophylactic ibuprofen are recommended. A new approach to patent ductus arteriosus management is an early targeted treatment based on echocardiographic criteria within the first 72 hours of life, that have a high sensitivity for diagnosing a patent ductus arteriosus that is unlikely to close spontaneously. Such trials are currently ongoing in many parts of the world. Results of such trials will be included in updates of our "Ibuprofen for treatment of PDA" review.

Fabrication of novel combinatorial drug encapsulated micelles for enhanced tumor targeting in intestinal cancer in mouse model

Hindrance to successful therapy of colon cancer is generally characterized with reduced potency of a single drug at the active site of cancer, poor drug release, and most importantly, potential toxic side effects of the drug resulting in cytotoxicity. Therefore, we investigated combinatorial drug micelles which are a potent combination of twin anticancer drugs (indomethacin and piroxicam, IND+PIR mc) for successful therapeutics of colon cancer. The novel combinatorial micelles showed improved drug encapsulation efficiency, an in vitro burst release of the dual drugs, increased cytocompatibility and increased efficacy in tumor reduction (weight and volume) than in single drug micelles (IND mc or PIR mc). The improved IND+PIR MC were to have small size 150.36 ± 15.13 nm (to avoid being taken up by liver, lungs or kidney or to sediment) with poly dispersity index (PDI) value at 0.24 ± 0.01. The PDI values suggest homogenous distribution. Encapsulation efficiency of IND+PIR mc was calculated at 86%. IND+PR mc had improved biocompatibility as demonstrated by CRL-1459™ (normal colon) cell line than IND mc or PIR mc individually. The in vivo studies in mice model clearly depict that subcutaneous tumor weight reduced by almost 75% and volume reduced drastically by 55% on administration of IND+PIR mc than IND mc or PIR mc. Furthermore, fewer side effects were found with IND+PIR mc. To conclude, IND+PIR mc may be a potential anticancer strategy to be explored more in the future.

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

BACKGROUND

Patent ductus arteriosus (PDA) complicates the clinical course of preterm infants and increases the risk of adverse outcomes. Indomethacin has been the standard treatment to close a PDA but is associated with renal, gastrointestinal, and cerebral side effects. Ibuprofen has less effect on blood flow velocity to important organs.

OBJECTIVES

Primary objectivesTo determine the effectiveness and safety of ibuprofen compared to placebo/no intervention, or other cyclo-oxygenase inhibitor drugs in the prevention of PDA in preterm infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 10), MEDLINE via PubMed (1966 to 17 October 2018), Embase (1980 to 17 October 2018), and CINAHL; 1982 to 17 October 2018). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing ibuprofen with placebo/no intervention or other cyclo-oxygenase inhibitor drugs to prevent PDA in preterm or low birth weight infants.

DATA COLLECTION AND ANALYSIS

We extracted outcomes data including presence of PDA on day three or four of life (after 72 hours of treatment), need for surgical ligation or rescue treatment with cyclo-oxygenase inhibitors, mortality, cerebral, renal, pulmonary, and gastrointestinal complications. We performed meta-analyses and reported treatment estimates as typical mean difference (MD), risk ratio (RR), risk difference (RD) and, if statistically significant, number needed to treat to benefit (NNTB) or to harm (NNTH), along with their 95% confidence intervals (CI). We assessed between-study heterogeneity by the I-squared test (I²). We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

In this updated analysis, we included nine trials (N = 1070 infants) comparing prophylactic ibuprofen (IV or oral) with placebo/no intervention or indomethacin. Ibuprofen (IV or oral) probably decreases the risk of PDA on day 3 or 4 (typical RR 0.39, 95% CI 0.31 to 0.48; typical RD -0.26, 95% CI -0.31 to -0.21; NNTB 4, 95% CI 3 to 5; 9 trials; N = 1029) (moderate-quality evidence). In the control group, the spontaneous closure rate was 58% by day 3 to 4 of age. In addition, ibuprofen probably decreases the need for rescue treatment with cyclo-oxygenase inhibitors (typical RR 0.17, 95% CI 0.11 to 0.26; typical RD -0.27, 95% CI -0.32 to -0.22; NNTB 4; 95% CI 3 to 5),and the need for surgical ductal ligation (typical RR 0.46, 95% CI 0.22 to 0.96; typical RD -0.03, 95% CI -0.05 to -0.00; NNTB 33, 95% CI 20 to infinity; 7 trials; N = 925) (moderate-quality evidence). There was a possible decrease in the risk of grade 3 or 4 intraventricular haemorrhage (IVH) in infants receiving prophylactic ibuprofen (typical RR 0.67, 95% CI 0.45 to 1.00; I² = 34%; typical RD -0.04, 95% CI -0.08 to- 0.00; I² = 60%; 7 trials; N = 925) (moderate-quality evidence). High quality evidence showed increased risk for oliguria (typical RR 1.45, 95% CI 1.04 to 2.02; typical RD 0.06, 95% CI 0.01 to 0.11; NNTH 17, 95% CI 9 to 100; 4 trials; N = 747). Low quality results from four studies (N = 202) showed that administering oral ibuprofen may decrease the risk of PDA (typical RR 0.47, 95% CI 0.30 to 0.74) and may increase risk of gastrointestinal bleeding (NNTH 7, 95% CI 4 to 25). No evidence of a difference was identified for mortality, any intraventricular haemorrhage (IVH), or chronic lung disease.

AUTHORS' CONCLUSIONS

This review shows that prophylactic use of ibuprofen, compared to placebo or no intervention, probably decreases the incidence of patent ductus arteriosus, the need for rescue treatment with cyclo-oxygenase inhibitors, and for surgical ductal closure. Adverse effects associated with ibuprofen (IV or oral) included increased risks for oliguria, increase in serum creatinine levels, and increased risk of gastrointestinal haemorrhage. There was a reduced risk for intraventricular haemorrhage (grade III - IV) but no evidence of a difference in mortality, chronic lung disease, necrotising enterocolitis, or time to reach full feeds. In the control group, the patent ductus arteriosus had closed spontaneously by day 3 or 4 in 58% of neonates. Prophylactic treatment exposes a large proportion of infants unnecessarily to a drug that has important side effects without conferring any important short-term benefits. Current evidence does not support the use of ibuprofen for prevention of patent ductus arteriosus. Until long-term follow-up results of the trials included in this review have been published, no further trials of prophylactic ibuprofen are recommended.A new approach to patent ductus arteriosus management is an early targeted treatment based on echocardiographic criteria within the first 72 hours of life, that have a high sensitivity for diagnosing a patent ductus arteriosus that is unlikely to close spontaneously. Such trials are currently ongoing in many parts of the world. Results of such trials will be included in updates of our "Ibuprofen for treatment of PDA" review.

Ibuprofen for the treatment of patent ductus arteriosus in preterm or low birth weight (or both) infants

BACKGROUND

Indomethacin is used as standard therapy to close a patent ductus arteriosus (PDA) but is associated with reduced blood flow to several organs. Ibuprofen, another cyclo-oxygenase inhibitor, may be as effective as indomethacin with fewer adverse effects.

OBJECTIVES

To determine the effectiveness and safety of ibuprofen compared with indomethacin, other cyclo-oxygenase inhibitor(s), placebo, or no intervention for closing a patent ductus arteriosus in preterm, low-birth-weight, or preterm and low-birth-weight infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 10), MEDLINE via PubMed (1966 to 30 November 2017), Embase (1980 to 30 November 2017), and CINAHL (1982 to 30 November 2017). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of ibuprofen for the treatment of a PDA in preterm, low birth weight, or both preterm and low-birth-weight newborn infants.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of the Cochrane Neonatal Review Group. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included 39 studies enrolling 2843 infants.Ibuprofen (IV) versus placebo: IV Ibuprofen (3 doses) reduced the failure to close a PDA compared with placebo (typical relative risk (RR); 0.62 (95% CI 0.44 to 0.86); typical risk difference (RD); -0.18 (95% CI -0.30 to -0.06); NNTB 6 (95% CI 3 to 17); I² = 65% for RR and I² = 0% for RD; 2 studies, 206 infants; moderate-quality the evidence). One study reported decreased failure to close a PDA after single or three doses of oral ibuprofen compared with placebo (64 infants; RR 0.26, 95% CI 0.11 to 0.62; RD -0.44, 95% CI -0.65 to -0.23; NNTB 2, 95% CI 2 to 4; I² test not applicable).Ibuprofen (IV or oral) compared with indomethacin (IV or oral): Twenty-four studies (1590 infants) comparing ibuprofen (IV or oral) with indomethacin (IV or oral) found no significant differences in failure rates for PDA closure (typical RR 1.07, 95% CI 0.92 to 1.24; typical RD 0.02, 95% CI -0.02 to 0.06; I² = 0% for both RR and RD; moderate-quality evidence). A reduction in NEC (necrotising enterocolitis) was noted in the ibuprofen (IV or oral) group (18 studies, 1292 infants; typical RR 0.68, 95% CI 0.49 to 0.94; typical RD -0.04, 95% CI -0.07 to -0.01; NNTB 25, 95% CI 14 to 100; I² = 0% for both RR and RD; moderate-quality evidence). There was a statistically significant reduction in the proportion of infants with oliguria in the ibuprofen group (6 studies, 576 infants; typical RR 0.28, 95% CI 0.14 to 0.54; typical RD -0.09, 95% CI -0.14 to -0.05; NNTB 11, 95% CI 7 to 20; I² = 24% for RR and I² = 69% for RD; moderate-quality evidence). The serum/plasma creatinine levels 72 hours after initiation of treatment were statistically significantly lower in the ibuprofen group (11 studies, 918 infants; MD -8.12 µmol/L, 95% CI -10.81 to -5.43). For this comparison, there was high between-study heterogeneity (I² = 83%) and low-quality evidence.Ibuprofen (oral) compared with indomethacin (IV or oral): Eight studies (272 infants) reported on failure rates for PDA closure in a subgroup of the above studies comparing oral ibuprofen with indomethacin (IV or oral). There was no significant difference between the groups (typical RR 0.96, 95% CI 0.73 to 1.27; typical RD -0.01, 95% CI -0.12 to 0.09; I² = 0% for both RR and RD). The risk of NEC was reduced with oral ibuprofen compared with indomethacin (IV or oral) (7 studies, 249 infants; typical RR 0.41, 95% CI 0.23 to 0.73; typical RD -0.13, 95% CI -0.22 to -0.05; NNTB 8, 95% CI 5 to 20; I² = 0% for both RR and RD). There was low-quality evidence for these two outcomes. There was a decreased risk of failure to close a PDA with oral ibuprofen compared with IV ibuprofen (5 studies, 406 infants; typical RR 0.38, 95% CI 0.26 to 0.56; typical RD -0.22, 95% CI -0.31 to -0.14; NNTB 5, 95% CI 3 to 7; moderate-quality evidence). There was a decreased risk of failure to close a PDA with high-dose versus standard-dose of IV ibuprofen (3 studies 190 infants; typical RR 0.37, 95% CI 0.22 to 0.61; typical RD - 0.26, 95% CI -0.38 to -0.15; NNTB 4, 95% CI 3 to 7); I² = 4% for RR and 0% for RD); moderate-quality evidence).Early versus expectant administration of IV ibuprofen, echocardiographically-guided IV ibuprofen treatment versus standard IV ibuprofen treatment, continuous infusion of ibuprofen versus intermittent boluses of ibuprofen, and rectal ibuprofen versus oral ibuprofen were studied in too few trials to allow for precise estimates of any clinical outcomes.

AUTHORS' CONCLUSIONS

Ibuprofen is as effective as indomethacin in closing a PDA. Ibuprofen reduces the risk of NEC and transient renal insufficiency. Therefore, of these two drugs, ibuprofen appears to be the drug of choice. The effectiveness of ibuprofen versus paracetamol is assessed in a separate review. Oro-gastric administration of ibuprofen appears as effective as IV administration. To make further recommendations, studies are needed to assess the effectiveness of high-dose versus standard-dose ibuprofen, early versus expectant administration of ibuprofen, echocardiographically-guided versus standard IV ibuprofen, and continuous infusion versus intermittent boluses of ibuprofen. Studies are lacking evaluating the effect of ibuprofen on longer-term outcomes in infants with PDA.

Different Chromatographic Methods for Simultaneous Determination of Mefenamic Acid and Two of Its Toxic Impurities

Two sensitive, accurate and precise chromatographic methods mentioned as TLC-densitometric method and RP-HPLC-DAD method, were developed and validated for the simultaneous determination of mefenamic acid (MEF) and its two toxic impurities, benzoic acid (BA) and 2,3-dimethylaniline (DMA). In the proposed TLC-densitometric method a developing system consisting of chloroform:acetone:acetic acid:ammonia solution(70:30:2:2, v/v/v/v) was used, TLC aluminum plates 60 F254 was used as a stationary phase and the separated bands were UV-scanned at 225 nm. While the proposed RP-HPLC-DAD method depended on chromatographic separation on C18 column using 0.05 M KH2PO4 buffer: acetonitrile (40:60, v/v) as a mobile phase at constant flow rate of 1 mL/min with UV detection at 225 nm. Linear relationships were obtained in the ranges of 0.3-2, 0.3-2 and 0.3-1.8 μg/band (for TLC-densitometric method) and in the ranges of 7-50, 10-50 and 7-50 μg/mL (for HPLC-DAD method) for MEF, BA and DMA, respectively. Factors affecting the developed methods have been studied and optimized. Moreover ,the proposed methods were successfully applied for determination of the studied drug in its pharmaceutical dosage form. The methods showed no significance difference when compared with the reported method using F-test and Student's-t test. The low of detection and quantization limits of the proposed methods get them suitable for quality control and stability studies of MEF in pharmaceutical formulation. The developed methods have advantages of being more selective and sensitive than the published methods.

Ibuprofen for the treatment of patent ductus arteriosus in preterm or low birth weight (or both) infants

BACKGROUND

Indomethacin is used as standard therapy to close a patent ductus arteriosus (PDA) but is associated with reduced blood flow to several organs. Ibuprofen, another cyclo-oxygenase inhibitor, may be as effective as indomethacin with fewer adverse effects.

OBJECTIVES

To determine the effectiveness and safety of ibuprofen compared with indomethacin, other cyclo-oxygenase inhibitor, placebo or no intervention for closing a patent ductus arteriosus in preterm, low birth weight, or preterm and low birth weight infants.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, EMBASE, Clincialtrials.gov, Controlled-trials.com, and www.abstracts2view.com/pas in May 2014.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of ibuprofen for the treatment of a PDA in newborn infants.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

We included 33 studies enrolling 2190 infants.Two studies compared intravenous (iv) ibuprofen versus placebo (270 infants). In one study (134 infants) ibuprofen reduced the incidence of failure to close a PDA (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.51 to 0.99; risk difference (RD) -0.18, 95% CI -0.35 to -0.01; number needed to treat for an additional beneficial outcome (NNTB) 6, 95% CI 3 to 100). In one study (136 infants), ibuprofen reduced the composite outcome of infant mortality, infants who dropped out, or infants who required rescue treatment (RR 0.58, 95% CI 0.38 to 0.89; RD -0.22, 95% CI -0.38 to -0.06; NNTB 5, 95% CI 3 to 17). One study (64 infants) compared oral ibuprofen with placebo and noted a significant reduction in failure to close a PDA (RR 0.26, 95% CI 0.11 to 0.62; RD -0.44, 95% CI -0.65 to -0.23; NNTB 2, 95% CI 2 to 4).Twenty-one studies (1102 infants) reported failure rates for PDA closure with ibuprofen (oral or iv) compared with indomethacin (oral or iv). There was no significant difference between the groups (typical RR 1.00, 95% CI 0.84 to 1.20; I(2) = 0%; typical RD 0.00, 95% CI -0.05 to 0.05; I(2) = 0%). The risk of developing necrotising enterocolitis (NEC) was reduced for ibuprofen (16 studies, 948 infants; typical RR 0.64, 95% CI 0.45 to 0.93; typical RD -0.05, 95% CI -0.08 to -0.01; NNTB 20, 95% CI 13 to 100; I(2) = 0% for both RR and RD). The duration of ventilatory support was reduced with ibuprofen (oral or iv) compared with iv or oral indomethacin (six studies, 471 infants; mean difference (MD) -2.4 days, 95% CI -3.7 to -1.0; I(2) = 19%).Eight studies (272 infants) reported on failure rates for PDA closure in a subgroup of the above studies comparing oral ibuprofen with indomethacin (oral or iv). There was no significant difference between the groups (typical RR 0.96, 95% CI 0.73 to 1.27; typical RD -0.01, 95% CI -0.12 to 0.09). The risk of NEC was reduced with oral ibuprofen compared with indomethacin (oral or iv) (seven studies, 249 infants; typical RR 0.41, 95% CI 0.23 to 0.73; typical RD -0.13, 95% CI -0.22 to -0.05; NNTB 8, 95% CI 5 to 20; I(2) = 0% for both RR and RD). There was a decreased risk of failure to close a PDA with oral ibuprofen compared with iv ibuprofen (four studies, 304 infants; typical RR 0.41, 95% CI 0.27 to 0.64; typical RD -0.21, 95% CI -0.31 to -0.12; NNTB 5, 95% CI 3 to 8). Transient renal insufficiency was less common in infants who received ibuprofen compared with indomethacin. High dose versus standard dose of iv ibuprofen, early versus expectant administration of iv ibuprofen, echocardiographically guided iv ibuprofen treatment vs. standard iv ibuprofen treatment and continuous infusion of ibuprofen vs. intermittent boluses of ibuprofen and long-term follow-up were studied in too few trials to draw any conclusions.

AUTHORS' CONCLUSIONS

Ibuprofen is as effective as indomethacin in closing a PDA and currently appears to be the drug of choice. Ibuprofen reduces the risk of NEC and transient renal insufficiency. Oro-gastric administration of ibuprofen appears as effective as iv administration. To make further recommendations, studies are needed to assess the effectiveness of high-dose versus standard-dose ibuprofen, early versus expectant administration of ibuprofen, echocardiographically guided versus standard iv ibuprofen, and continuous infusion versus intermittent boluses of ibuprofen. Studies are lacking evaluating the effect of ibuprofen on longer-term outcomes in infants with PDA.

Trace analysis of mefenamic acid in human serum and pharmaceutical wastewater samples after pre-concentration with Ni-Al layered double hydroxide nano-particles

In this work, the nickel–aluminum layered double hydroxide (Ni–Al LDH) with nitrate interlayer anion was synthesized and used as a solid phase extraction sorbent for the selective separation and pre-concentration of mefenamic acid prior to quantification by UV detection at λ_max=286 nm. Extraction procedure is based on the adsorption of mefenamate anions on the Ni–Al(NO₃⁻) LDH and/or their exchange with LDH interlayer NO₃⁻ anions. The effects of several parameters such as cations and interlayer anions type in LDH structure, pH, sample flow rate, elution conditions, amount of nano-sorbent and co-existing ions on the extraction were investigated and optimized. Under the optimum conditions, the calibration graph was linear within the range of 2–1000 µg/L with a correlation coefficient of 0.9995. The limit of detection and relative standard deviation were 0.6 µg/L and 0.84% (30 µg/L, n=6), respectively. The presented method was successfully applied to determine of mefenamic acid in human serum and pharmaceutical wastewater samples.

Carbon dots as nanoantennas for anti-inflammatory drug analysis using surface-assisted laser desorption/ionization time-of-flight mass spectrometry in serum

C-dots assisted LDI MS method has been developed for the detection of Mefenamic acid in serum.

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

BACKGROUND

Indomethacin is used as standard therapy to close a patent ductus arteriosus (PDA) but is associated with reduced blood flow to several organs. Ibuprofen, another cyclo-oxygenase inhibitor, may be as effective as indomethacin with fewer side effects.

OBJECTIVES

To determine the efficacy and safety of ibuprofen for closing a PDA in preterm and/or low birth weight infants. Seperate comparisons are presented for 1. ibuprofen (iv) compared with placebo; 2. ibuprofen (oral) compared with placebo; 3. ibuprofen (oral or iv) compared with other cyclo-oxygenase inhibitors (given iv or orally); 4. ibuprofen (oral) versus indomethacin (given iv or orally); 5. ibuprofen (oral) versus iv ibuprofen; 6. high dose versus standard dose of iv ibuprofen; 7. early versus expectant administration of iv ibuprofen.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, EMBASE, Clincialtrials.gov, Controlled-trials.com, www.abstracts2view.com/pas, and personal files in July 2012.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of ibuprofen for the treatment of a PDA in newborn infants.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Twenty-seven studies are included in this review. One study (n = 136) compared iv ibuprofen versus placebo. Ibuprofen reduced the composite outcome of infant deaths, infants who dropped out or required rescue treatment; risk ratio (RR) 0.58 (95% confidence interval (CI) 0.38 to 0.89); risk difference (RD) -0.22 (95% CI -0.38 to -06); number needed to benefit (NNTB) 5 (95% CI 3 to 17). One study (n = 64) compared oral ibuprofen with placebo. There was a significant reduction in the failure rate to close a PDA; RR 0.26 (95% CI 0.11 to 0.62); RD -0.44 (95% CI -0.65 to -0.23); NNTB 2 (95% CI 2 to 4). Failure rates for PDA closure with ibuprofen (oral or iv) compared with indomethacin (oral or iv) was reported in 20 studies (n = 1019 infants). There was no significant difference between the groups; typical RR 0.98 (95% CI 0.80 to 1.20) I(2) = 0%; typical RD -0.01 (95% CI -0.06 to 0.05); I(2) = 0%. The risk of developing necrotising enterocolitis (NEC) was reduced for ibuprofen (15 studies (n = 865); typical RR 0.68 (95% CI 0.47 to 0.99); typical RD -0.04 (95% CI -0.08 to -0.00; (P = 0.04); NNTB 25 (95% CI 13, infinity); I(2) = 0%). The duration of ventilatory support was reduced with ibuprofen (oral or iv) compared with iv or oral indomethacin (six studies, n = 471) mean difference (MD) -2.35 days (95% CI -3.71 to -0.99); I(2) = 19%. Failure rates for PDA closure with oral ibuprofen compared with indomethacin (oral or iv) were reported in seven studies (n = 189 infants). There was no significant difference between the groups; typical RR 0.82 (95% CI 0.52 to 1.29); typical RD -0.06 (95% CI -0.18 to 0.06). The risk of NEC was reduced with oral ibuprofen compared with indomethacin (oral or iv) six studies (n = 166); typical RR 0.44 (95% CI 0.23 to 0.82); RD -0.15 (95% CI -0.25 to -0.04); NNTB 7 (95% CI 4 to 25). There was no heterogeneity for this outcome. There was a decreased risk of failure to close a PDA with oral ibuprofen compared with iv ibuprofen, three studies (n = 236) typical RR 0.37 (95% CI 0.23 to 0.61); typical RD -0.24 (95% CI -0.35 to -0.13); NNTB 4 (95% CI 3 to 8). There was less evidence of transient renal insufficiency in infants who received ibuprofen compared with indomethacin. High dose versus standard dose of iv ibuprofen and early versus expectant administration of iv ibuprofen have only been studied in two trials.

AUTHORS' CONCLUSIONS

Ibuprofen is as effective as indomethacin in closing a PDA and reduces the risk of NEC and transient renal insufficiency. Given the reduction in NEC ibuprofen currently appears to be the drug of choice. Oro-gastric administration of ibuprofen appears at least as effective as iv administration. Too few patients have been enrolled in studies assessing the effectiveness of a high dose of ibuprofen versus the standard dose and early versus expectant administration of ibuprofen to make recommendations. Studies are needed to evaluate the effect of ibuprofen compared with indomethacin treatment on longer-term outcomes in infants with PDA.

A liquid chromatography method with single quadrupole mass spectrometry for quantitative determination of indomethacin in maternal plasma and urine of pregnant patients

A liquid chromatography with single quadrupole mass spectrometry method was developed for the quantitative determination of indomethacin in the maternal plasma and urine of pregnant patients under treatment. A deuterium-labeled isotope of indomethacin (d4-indomethacin) was used as an internal standard. The maternal plasma and urine samples were acidified with 1.0M HCl then extracted with chloroform to achieve the extraction recovery range of 94-104% with variation less than 11%. Chromatographic separation was achieved by a Waters Symmetry C₁₈ column with isocratic elution of 0.05% (v/v) formic acid aqueous solution and acetonitrile (47:53, v/v). An in-source fragmentation was applied on the single quadrupole mass spectrometer equipped with an electrospray ionization source at positive mode. The LC-ESI-MS quantification was performed in the selected ion monitoring mode targeting ions at m/z 139 for indomethacin and m/z 143 for its internal standard. The calibration curves were linear in the concentration ranges between 14.8 and 2.97 × 10(3) ng/mL for plasma samples and between 10.5 and 4.21 × 10(3) ng/mL for urine samples. The relative standard deviation of this method was less than 8% for intra- and inter-day assays, and the accuracy ranged between 90% and 108%.

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

BACKGROUND

Patent ductus arteriosus (PDA) complicates the clinical course of preterm infants and increases the risk of adverse outcomes. Indomethacin has been the standard treatment to close a PDA but is associated with renal, gastrointestinal and cerebral side-effects. Ibuprofen has less effect on blood flow velocity to important organs.

OBJECTIVES

To determine the effectiveness and safety of prophylactic ibuprofen compared to placebo/no intervention in the prevention of PDA in preterm infants.

SEARCH STRATEGY

Randomized controlled trials of prophylactic ibuprofen were identified by searching in The Cochrane Library, MEDLINE, CINAHL, EMBASE and trials registries in December 2010.

SELECTION CRITERIA

Randomized or quasi-randomised controlled trials comparing ibuprofen with placebo/no intervention or other cyclo-oxygenase inhibitor drugs to prevent PDA in preterm and/or low birth weight infants.

DATA COLLECTION AND ANALYSIS

Outcomes data including presence of PDA on day three, need for surgical ligation or rescue treatment with cyclo-oxygenase inhibitors, mortality, intraventricular haemorrhage (IVH), renal, pulmonary and gastrointestinal complications were extracted. Meta-analyses were performed and treatment estimates are reported as typical weighted mean difference, relative risk (RR), risk difference (RD) and, if statistically significant, number needed to treat to benefit (NNT) or number needed to treat to harm (NNH) along with their 95% confidence intervals (CI).

MAIN RESULTS

In this update, seven studies (n = 931) comparing prophylactic ibuprofen with placebo/no intervention are included. Ibuprofen decreased the incidence of PDA on day three [typical RR 0.36 (95% CI 0.29 to 0.46); typical RD -0.27 (95% CI -0.32 to -0.21); NNT 4 (95% CI 3 to 5)], decreased the need for rescue treatment with cyclo-oxygenase inhibitors and decreased the need for surgical ligation. Results from two studies administering oral ibuprofen had similar results, but showed an increased risk of gastrointestinal bleeding (NNH 4, 95% CI 2 to 17). In the control group the spontaneous closure rate was 58% by day three. Ibuprofen negatively affects renal function. No significant differences in mortality, IVH, chronic lung disease were found.

AUTHORS' CONCLUSIONS

Prophylactic use of ibuprofen decreased the incidence of PDA, decreased the need for rescue treatment with cyclo-oxygenase inhibitors and decreased the need for surgical closure. In the control group, the PDA closed spontaneously by day three in 58% of the neonates. Prophylactic treatment exposes many infants to a drug that has concerning renal and gastrointestinal side effects without conferring any important short-term benefits and is not recommended. Until long-term follow-up results are published from the trials included in this updated review, no further trials of prophylactic ibuprofen are recommended.

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

BACKGROUND

Indomethacin is used as standard therapy to close a patent ductus arteriosus (PDA) but is associated with reduced blood flow to several organs. Ibuprofen, another cyclo-oxygenase inhibitor, may be as effective as indomethacin 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 for closing a PDA in preterm and/or low birth weight infants.

SEARCH STRATEGY

MEDLINE, EMBASE, The Cochrane Library, the reference lists of identified studies, meta-analyses and personal files were searched in December 2009.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials of ibuprofen for the treatment of a PDA in newborn infants.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Twenty studies are included in this review (6 studies added in this update). One study (n = 136) compared ibuprofen to placebo. Ibuprofen reduced the composite outcome of infant deaths, infants who dropped out or required rescue treatment [RR 0.58 (95% CI 0.38, 0.89); RD -0.22 (95% CI -0.38, -06); NNTB 5 (95% CI 3,17)]. Failure rates for PDA closure with ibuprofen compared to indomethacin was reported in 19 studies (n = 956 infants). There was no statistically significant difference between the groups [typical RR 0.94 (95% CI 0.76, 1.17)]; typical RD -0.02 (95% CI -0.07, 0.04); I(2) = 0%]. The risk of developing necrotizing enterocolitis (NEC) was reduced for ibuprofen [15 studies (n = 865); typical RR 0.68 (95% CI 0.47, 0.99); typical RD -0.04 (95% CI -0.08, -0.00; (p = 0.04); NNTB 25 (95% CI 13, infinity); I(2) = 0%]. There is less evidence of transient renal insufficiency in infants who receive ibuprofen compared to indomethacin. No other important differences were noted for common neonatal morbidities. Oro-gastric administration of ibuprofen appears as effective as i.v. administration.

AUTHORS' CONCLUSIONS

Ibuprofen is effective in closing a PDA. Ibuprofen is as effective as indomethacin in closing a PDA and reduces the risk of NEC and transient renal insufficiency. Given the reduction in NEC noted in this update, ibuprofen currently appears to be the drug of choice. Studies are needed to evaluate the effect of ibuprofen compared to indomethacin treatment on longer term outcomes in infants with PDA.

Ibuprofen for the treatment of 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 gastrointestinal tract. Ibuprofen, another cyclo-oxygenase inhibitor, may be as effective as indomethacin, 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 Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2007), MEDLINE (1996 - August 2007), CINAHL (1982 - August 2007), EMBASE (1980 - August 2007), 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 - April 2005) or on their website (to August 2007). No language restrictions were applied.

SELECTION CRITERIA

1) DESIGN: Randomized or quasi-randomized controlled trials2) POPULATION: Preterm (< 37 weeks gestational age) or low birth weight infants (< 2500 g) with a clinically or echocardiographically diagnosed PDA3) INTERVENTION: Administration of ibuprofen (orally or intravenously) for the closure of PDA4) OUTCOMES: At least one of the following outcomes were reported: failure to close a PDA, mortality, surgical ductal ligation, intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL), NEC, decreased urine output, retinopathy of prematurity (ROP), chronic lung disease (CLD), sepsis, pulmonary hemorrhage, pulmonary hypertension, duration of supplementary oxygen, duration of mechanical ventilation, duration of hospital stay, and serum creatinine levels following treatment.

DATA COLLECTION AND ANALYSIS

At least two review authors worked independently at each step of the original review, then compared results and resolved differences. The current update was conducted by one review author (AO). Methodological quality of eligible studies was assessed according to blinding of randomization, of intervention and of outcome assessment, and completeness of follow up. Weighted treatment effects, calculated using RevMan 4.2.10, included typical relative risk (RR), typical risk difference (RD), number needed to treat to benefit (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 including the I-squared test (I(2)) were performed to assess the appropriateness of pooling the data.

MAIN RESULTS

No studies using mefenamic acid were identified. Sixteen studies enrolling 876 infants were identified. Four additional trials were identified for this update and two studies published as abstracts were now available as full articles. One study compared ibuprofen to placebo, but the results were not reported unblinded to intervention group. Fifteen studies including 740 infants compared the effectiveness of ibuprofen to indomethacin for the closure of a PDA. For the primary outcome (failure of ductal closure), there was no statistically significant difference between ibuprofen and indomethacin groups [typical RR 0.99 (95% CI 0.78, 1.27); typical RD 0.00 (95% CI -0.06, 0.06)]. There were no statistically significant differences in mortality, reopening of the ductus, need for surgical duct ligation, duration of ventilator support, duration of supplementary oxygen, pulmonary hemorrhage, pulmonary hypertension, CLD, IVH, PVL, NEC, intestinal perforation, gastrointestinal bleed, time to full enteral feeds, time to regain birth weight, ROP, sepsis, duration of hospitalization. Ibuprofen treatment was associated with statistically significantly lower serum creatinine levels after treatment (6 trials, 336 infants; WMD - 8.2 (95% CI -13.3, -3.2) mmol/L and lower incidence of 'decreased urine output' [3 trials, 336 infants; typical RR; 0.22 (95% CI 0.09, 0.51); typical RD -0.12 (95% CI -0.18, -0.06); NNT 8 (95% CI 6,17)]. There was moderate heterogeneity of treatment effect for the outcomes 'time to regain birth weight' and 'decreased urine output". Heterogeneity was not noted for other outcomes. For several of these outcomes, the sample size was small and the estimates imprecise. There are not enough data available regarding the effectiveness of oral ibuprofen compared with indomethacin to close a PDA [3 trials, 69 infants; typical RR 1.41 (95% CI 0.68, 2.93); typical RD 0.10 (95% CI -0.10, 0.30)]. Pulmonary hypertension was noted in one infant receiving ibuprofen to close a PDA enrolled in a trial in this review and an additional report of such a case was identified from the literature.

AUTHORS' CONCLUSIONS

No statistically significant difference in the effectiveness of ibuprofen compared to indomethacin in closing a PDA was found. Ibuprofen compared with indomethacin reduces the risk of oliguria and is associated with lower serum creatinine levels following treatment. Pulmonary hypertension has been observed in three infants after prophylactic use of ibuprofen and one infant receiving ibuprofen for treatment in this review developed pulmonary hypertension. One additional case of pulmonary hypertension following treatment with ibuprofen to close a PDA was identified from the literature. The available data support the use of either drug for the treatment of a PDA. As both drugs are equally effective in closing a PDA, the clinician needs to weigh the potential side effects of one drug vs. the other when making a decision which drug to use. The most urgent research question to be answered is whether ibuprofen compared to indomethacin confers an improved rate of intact survival (survival without impairment) at 18 months corrected age and at the age of school entry.

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

BACKGROUND

A patent ductus arteriosus (PDA) often complicates the clinical course of preterm infants and increases the risk of intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), chronic lung disease (CLD) and death. The standard treatment to close a PDA is indomethacin. Its use is associated with renal, gastrointestinal and cerebral side-effects. Ibuprofen has been shown to be effective in closing a PDA without reducing blood flow velocity to the brain, gut or kidneys.

OBJECTIVES

To determine the effectiveness and safety of prophylactic ibuprofen compared to placebo/no intervention or other cyclo-oxygenase inhibitor drugs (indomethacin, mefenamic acid, etc) in the prevention of PDA in preterm infants.

SEARCH STRATEGY

Randomized controlled trials comparing prophylactic ibuprofen use with placebo/no intervention/indomethacin were identified by searching the Cochrane Central Register of Controlled Trial (CENTRAL, The Cochrane Library, Issue 3, 2005), MEDLINE (1966-July 2005), CINAHL (1982-July 2005), EMBASE (1980-July 2005), reference lists of published trials and abstracts published in Pediatric Research (1990-July 2005). No language restrictions were applied.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials comparing use of ibuprofen with placebo/no intervention or other cyclo-oxygenase inhibitor drugs (indomethacin, mefenamic acid, etc) for the prevention of PDA in preterm and/or low birth weight infants.

DATA COLLECTION AND ANALYSIS

Data regarding the clinical outcomes including presence of PDA on day three and day seven, need for surgical ligation, need for rescue treatment with cyclo-oxygenase inhibitors, IVH, mortality, renal and gastrointestinal complications were extracted. Meta-analyses were performed using RevMan 4.2 and treatment estimates were reported as weighted mean difference (WMD), typical relative risk (RR), typical risk difference (RD) and, if statistically significant, number needed to treat (NNT) or number needed to harm (NNH), along with their 95% confidence intervals (CI).

MAIN RESULTS

Four trials (n = 672) were included in the review. There was a statistically significant decrease in the incidence of PDA on day three in the ibuprofen group [typical RR 0.37 (95% CI 0.29, 0.49); typical RD -0.29 (95% CI -0.35, -0.22); NNT 3 (95% CI 3, 5); 4 trials, n = 672], in the need for rescue treatment with cyclo-oxygenase inhibitors [typical RR 0.17 (95% CI 0.11, 0.27), typical RD -0.27 (95% CI -0.35, -0.22); NNT 4 (95%CI 3, 5), and in the need for surgical ligation [typical RR 0.34 (95% CI 0.14, 0.81), typical RD -0.04 (95% CI -0.07, -0.01); NNT 25 (95% CI 14, 100). The PDA had closed spontaneously by day three in 60% of the neonates in the control group. There was a significant increase in the serum creatinine levels in the ibuprofen group [WMD 0.13 mg/dl (95% CI 0.08, 0.17); 2 trials, n = 495]. Ibuprofen reduces urine output. There were no statistically significant differences in mortality, grade 3/4 intraventricular hemorrhage, chronic lung disease at 28 days or 36 weeks, necrotizing enterocolitis , gastrointestinal hemorrhage, intestinal perforation or time to reach full feeds. One trial (Gournay 2002) (n = 135) reported on three infants in the ibuprofen group who developed pulmonary hypertension responsive to nitric oxide treatment.

AUTHORS' CONCLUSIONS

Prophylactic use of ibuprofen reduces the incidence of PDA, the need for rescue treatment with cyclo-oxygenase inhibitors and surgical closure. However, in the control group, the PDA had closed spontaneously by day three in 60% of the neonates. Prophylactic treatment therefore exposes a large proportion of infants unnecessarily to a drug that has important side effects (mainly involving the kidneys) without conferring any important short term benefits. Prophylactic treatment with ibuprofen is not recommended. Until long-term follow-up results are published from the trials included in this review, no further trials of prophylactic ibuprofen are recommended.

Determination of indomethacin in plasma by micellar electrokinetic chromatography with UV detection for premature infants with patent ducts arteriosus

A simple and selective micellar electrokinetic chromatography (MEKC) is described for determination of indomethacin in plasma. Plasma proteins are precipitated by acetonitrile. An aliquot of supernatant was evaporated and reconstituted with Tris buffer for MEKC analysis. The separation of indomethacin was performed at 25 degrees C using a background electrolyte consisting of Tris buffer (30 mM; pH 8.0) with 100 mM sodium octanesulfonate (SOS) as an anionic surfactant. Under this condition, a good separation with high efficiency and short analysis time is achieved. Several parameters affecting the separation of indomethacin were studied, including pH and concentrations of the Tris buffer and SOS. The linear range of the method for the determination of indomethacin was over 0.3-10.0 microg/mL; the detection limit (signal-to-noise ratio=3; injection 0.5 psi 5s) was 0.1 microg/mL. The proposed method for determination of indomethacin in premature infants with patent ducts arteriosus has been demonstrated.

Determinations of fluoroquinolones and nonsteroidal anti-inflammatory drugs in urine by extractive spectrophotometry and photoinduced spectrofluorimetry using multivariate calibration

Multivariate calibration methods are chemometric tools that may be applied to the analysis of spectroscopic data with multichannel detection. Two procedures, based on spectrophotometric and fluorimetric signals, are reported for the simultaneous determination of two fluoroquinolones (ciprofloxacin and ofloxacin) and two nonsteroidal anti-inflammatory drugs (diclofenac and mefenamic acid) using first- and second-order multivariate calibration methods. In the spectrophotometric method, an extractive procedure into chloroform using trioctylmethylammonium chloride-adogen as counter ion was optimized, with the object of extracting the analytes from urine samples and eliminating matrix interferences. After separation, the absorption spectrum of the organic phase was used as the analytical signal in a partial least squares method. A photoinduced spectrofluorimetric (PIF) method using excitation-emission fluorescence matrices, is proposed, to apply three-way chemometric calibration, with the aim of analyzing ofloxacin, ciprofloxacin, and diclofenac in urine samples without the previous extractive sample-cleaning step. For both procedures, recoveries around 100% were found for all the analytes. However, the PIF three-way chemometric method provides the most sensitive and selective procedure as the urine interferences are modulated using the three-way chemometric technique.

Ibuprofen for the treatment of 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 Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2005), MEDLINE (1996 - July 2005), CINAHL (1982 - July 2005), EMBASE (1980 - July 2005), 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 - April 2005). 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), chronic lung disease (CLD), sepsis, days on supplementary oxygen.

DATA COLLECTION AND ANALYSIS

At least two authors worked independently at each step of the original review, then compared results and resolved differences. The current update was conducted by one author (AO). Methodological quality of eligible studies was assessed according to blinding of randomization, of intervention and of outcome assessment, and completeness of follow up. Weighted treatment effects, calculated using RevMan 4.2, 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 including I(2 )were performed to assess the appropriateness of pooling the data.

MAIN RESULTS

No study using mefenamic acid was identified. One study compared ibuprofen to placebo but results were not reported unblinded to group. Eleven studies including 620 patients 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 [typical RR 0.96 (95% CI 0.74, 1.25)]. 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. CLD defined as oxygen requirement at 28 days post-natally was statistically significantly more likely to occur in the ibuprofen group [typical RR 1.37 (95% CI 1.01, 1.86); NNH 7 (95% CI 3 - 100)]. There was a similar trend for CLD at 36 weeks corrected gestational age.

AUTHORS' 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 CLD, 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. The most urgent research question to be answered is weather ibuprofen compared to indomethacin confers an improved rate of intact survival (survival without impairment) at 18 months corrected age.

Development and validation of HPLC method for determination of indomethacin and its two degradation products in topical gel

Indomethacin forms by decomposition two degradation products: 4-chlorobenzoic acid and 5-methoxy-2-methylindoleacetic acid. They have to be monitored together with an active substance both during manufacturing process and storage of pharmaceuticals. European Pharmacopoeia (Ph. Eur. 4) describes titration method for determination of indomethacin, which is not very convenient in this case for practical use. Therefore, high performance liquid chromatography is the method-of-choice enabling determination of active substance and its degradation products during one-step procedure simultaneously and automatically. We have developed a fast, simple and fully automated analytical method for determination of indomethacin and its two impurities in pharmaceutical preparation using HPLC with UV detection. Various stationary phases were tested, especially new types of Zorbax columns made by Agilent. While the conventional C18 stationary phases were not convenient enough to achieve quick and reliable separation, Zorbax-Phenyl analytical column (75 mm x 4.6 mm, 3.5 microm) enables separation of indomethacin and its two degradation products during 7.5 min. Chromatography was performed using isocratic elution with binary mobile phase composed of acetonitrile and 0.2% phosphoric acid (50:50, v/v) at flow rate 0.6 ml/min. Even faster separation of standards was obtained with analytical column Zorbax SB-CN (150 mm x 4.6 mm, 5 microm). The separation was effected with mobile phase of the same composition, only the flow rate was increased to 1.2 ml/min. The analytical run was shortened to 5 min. Both methods use detection wavelength 237 nm and both can use either ketoprofen or flurbiprofen as internal standard for quantitation. The first method was finally chosen for validation because of the occurrence of placebo interferences in the case of using Zorbax SB-CN. System suitability parameters and validation parameters including method precision, accuracy, linearity, selectivity and robustness were set up. Afterwards, the method was successfully applied for the practical determination of indomethacin and its degradation products in a topical gel and for compound degradation control during stability studies.

Liquid chromatography method for determination of mefenamic acid in human serum

A simple, rapid and specific method for analysis of mefenamic acid (I) in serum by a sensitive high-performance liquid chromatography is described. Only 70 microl of serum and a little sample work-up is required. A simple procedure of extraction by dichloromethane followed by evaporation to dryness under gentle stream of nitrogen and dissolving the dried residue in mobile phase was used. The mefenamic acid peak was separated from endogenous peaks on a C(8) column by a mobile phase of acetonitrile-water (50:50, v/v, pH 3). Mefenamic acid and internal standard (IS) (diclofenac) were eluted at 7.4 and 5.4 min, respectively. The limit of quantitation of mefenamic acid in serum was 25 ng/ml at 280 nm. The method was linear over the range of 25-2000 ng/ml with r(2) of 0.998. Mean recovery for mefenamic acid was 110%.

Square-wave adsorptive cathodic stripping voltammetric determination of anti-inflammatory indomethacin drug in tablets and human serum at a mercury electrode

Indomethacin is a non-steroidal anti-inflammatory drug possessing anti-pyretic and analgesic properties. A fully validated square-wave adsorptive cathodic stripping voltammetric procedure is described for determination of indomethacin. The procedure was based on the reduction of the C=O double bond of the drug molecule in Britton-Robinson buffer (pH 4) after its preconcentration onto the mercury electrode surface. The optimized conditions of the procedure were: frequency 120 Hz, scan increment 10 mV, pulse amplitude 50 mV, preconcentration potential -0.9 V (vs. Ag/AgCl/KCl(s)) and preconcentration time 90 s. The proposed procedure was successfully applied for determination of the drug in tablets and human serum with good recoveries. The limits of detection in bulk form and human serum were 6.7 x 10(-10) mol L(-1) and 8.1 x 10(-10) mol L(-1), respectively.

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

BACKGROUND

A patent ductus arteriosus (PDA) often complicates the clinical course of preterm infants and increases the risk of intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), chronic lung disease (CLD) and death. The standard treatment to close a PDA is indomethacin. Its use is associated with renal, gastrointestinal and cerebral side-effects. Ibuprofen has been shown to be effective in closing a PDA without reducing blood flow velocity to the brain, gut or kidneys.

OBJECTIVES

To determine the effectiveness and safety of prophylactic ibuprofen compared to placebo/no intervention or other cyclo-oxygenase inhibitor drugs (indomethacin, mefenamic acid, etc) in the prevention of PDA in preterm infants.

SEARCH STRATEGY

Randomized controlled trials comparing prophylactic ibuprofen use with placebo/no intervention/indomethacin were identified by searching the Cochrane Controlled Trial Register (The Cochrane Library, Issue 4, 2002), MEDLINE (1966-November 2002), CINAHL (1982-November 2002), EMBASE (1980-November 2002), reference lists of published trials and abstracts published in Pediatric Research (1990-2002). No language restrictions were applied.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials comparing use of ibuprofen with placebo/no intervention or other cyclo-oxygenase inhibitor drugs (indomethacin, mefenamic acid, etc) for the prevention of PDA in preterm and/or low birth weight infants.

DATA COLLECTION AND ANALYSIS

Data regarding the clinical outcomes including presence of PDA on day three and day seven, need for surgical ligation, need for rescue treatment with cyclo-oxygenase inhibitors, IVH, mortality, renal and gastrointestinal complications were extracted. Meta-analyses were performed using RevMan 4.1 and treatment estimates were reported as weighted mean difference (WMD), typical relative risk (RR), typical risk difference (RD) and, if statistically significant, number needed to treat (NNT) or number needed to harm (NNH), along with their 95% confidence intervals (CI).

MAIN RESULTS

Four trials (n = 623) were included in the review. There was a statistically significant decrease in the incidence of PDA on day three in the ibuprofen group [typical RR 0.36 (95% CI 0.26, 0.49); typical RD -0.29 (95% CI -0.37, -0.21); NNT 3 (95% CI 3, 5); 3 trials, n = 488]. There was a significant increase in the serum creatinine levels in the ibuprofen group [WMD 0.11 mg/dl (95% CI 0.06, 0.17); 2 trials, n = 438]. There were no statistically significant differences in mortality, grade 3 or 4 IVH, CLD at 28 days or 36 weeks, need for surgical closure of PDA, NEC, GI hemorrhage, time to reach full feeds and urine output. One trial (Gournay 2002) (n = 135) reported on three infants in the ibuprofen group who developed pulmonary hypertension responsive to nitric oxide treatment.

REVIEWER'S CONCLUSIONS

Prophylactic use of ibuprofen reduces the incidence of PDA. However, further trials, which address potential adverse effects including pulmonary hypertension, are needed. Such trials should include long-term neurodevelopmental outcomes. Trials comparing the effectiveness of prophylactic use of indomethacin versus ibuprofen may be warranted with particular reference to IVH, need for surgical ligation and neurodevelopmental outcome.

Indomethacin-loaded methoxy poly(ethylene glycol)/ poly(epsilon-caprolactone) diblock copolymeric nanosphere: pharmacokinetic characteristics of indomethacin in the normal Sprague-Dawley rats

We prepared the drug-loaded polymeric nanospheres composed of the methoxy poly(ethylene glycol) (MePEG) and poly(epsilon-caprolactone) (PCL) that showed a narrow size distribution and average diameter of less than 200 nm. We could obtain the nanosphere having a relatively high drug-loading efficiency of about 42% when the feed weight ratio of indomethacin (IMC) to polymer was 1:1. To investigate the IMC pharmacokinetics in the IMC-loaded MePEG/PCL nanosphere (DMEP70) using the rats as animal model, we analyzed the IMC concentration in plasma with HPLC after i.v. bolus administered at a dose of 10 mg/kg in free IMC (control) and IMC-loaded MePEG/PCL nanosphere (DMEP70) groups via tail vein. Pharmacokinetics parameters (mean +/- s.d.) such as the mean residence time (MRT, h), the steady-state volume of distribution (Vdss, l), the terminal half-time (t 1/2, h) and the plasma clearance (CL, l/h) of IMC in each groups (control vs. DMEP70) were determined; MRT (16.97 +/- 4.83 vs. 28.69 +/- 11.28, p < 0.01); Vdss (14.26 +/- 4.86 vs. 20.37 +/- 12.04, p < 0.05); t 1/2 (15.12 +/- 4.77 vs. 23.1 +/- 8.24, p < 0.01); CL (0.84 +/- 0.27 vs. 0.71 +/- 0.41). From these results, we could concluded that MEP70 has a significant potential for sustained release and the enhancement of circulation time of loaded drug by prolonging terminal half-life, increasing MRT and Vdss of IMC. Therefore, The MePEG/PCL block copolymeric nanosphere system is being considered as promising biodegradable and biocompatible drug carrier vehicles for parentral use and may be useful as sustained release injectable delivery systems for hydrophobic drugs.

Simultaneous analysis of anthranilic acid derivatives in pharmaceuticals and human urine by high-performance liquid chromatography with isocratic elution

A high-performance liquid chromatographic (HPLC) method for simultaneous determination of mefenamic acid (MFA), flufenamic acid (FFA) and tolfenamic acid (TFA) is presented for application to pharmaceuticals and human urine. Isocratic reversed-phase HPLC was employed for quantitative analysis using tetra-pentylammonium bromide (TPAB) as an ion-pair reagent. Urine samples were purified by solid-phase extraction using a silica-based strong anion-exchanger, Bond-Elut SAX cartridge. The HPLC assay was carried out using a Wakosil ODS 5C18 column (5 microm, 150x4.6 mm I.D.). The mobile phase consisted of 1.9 g of TPAB dissolved in 1:1 of a mixture of acetic acid-sodium acetate buffer solution, pH 5.0, and acetonitrile (11:9, v/v). The calibration curves of MFA, FFA and TFA showed good linearity in the concentration range of 33-167 microg/ml with a wavelength of 280 nm for pharmaceuticals, and in the low concentration range (1.7-30.1 microg/ml) with a wavelength of 230 nm for biological fluids. The correlation coefficients were better than 0.9999 in all cases. The lower limits of detection (defined as a signal-to-noise ratio of about 3) were approximately 2 ng for MFA, 3.5 ng for FFA and 2.5 ng for TFA. The procedure described here is rapid, simple, selective and is suitable for routine analysis of pharmaceuticals and pharmacokinetic studies in human urine samples.

Study of the solid-phase extraction of diclofenac sodium, indomethacin and phenylbutazone for their analysis in human urine by liquid chromatography

A selective semi-automated solid-phase extraction (SPE) of the non-steroidal anti-inflammatory drugs diclofenac sodium, indomethacin and phenylbutazone from urine prior to high-performance liquid chromatography was investigated. The drugs were recovered from urine buffered at pH 5.0 using C18 Bond-Elut cartridges as solid sorbent material and mixtures of methanol-aqueous buffer or acetonitrile-aqueous buffer as washing and elution solvents. The extracts were chromatographed on a reversed-phase ODS column using 10 mM acetate buffer (pH 4.0)-acetonitrile (58:42, v/v) as the mobile phase, and the effluent from the column was monitored at 210 nm with ultraviolet detection. Absolute recoveries of the anti-inflammatory drugs within the range 0.02-1.0 microg/ml were about 85% for diclofenac and indomethacin, and 50% for phenylbutazone without any interference from endogenous compounds of the urine. The within-day and between-day repeatabilities were in all cases less than 5% and 10%, respectively. Limits of detection were 0.007 microg/ml for diclofenac sodium and indomethacin and 0.035 microg/ml for phenylbutazone, whereas limits of quantitation were 0.02 microg/ml for diclofenac and indomethacin and 0.1 microg/ml for phenylbutazone.

The non-aqueous titrimetric assay of the selected anti-inflammatory agents using tetra-n-butylammonium hydroxide as titrant

A potentiometric titration method in non-aqueous media is proposed for the determination of some commonly used anti-inflammatory agents. The direct potentiometric titration of three anti-inflammatory agents, namely mefenamic acid, fenbufen and ibuprofen; and the indirect potentiometric titration of diclofenac sodium was carried out in acetonitrile solvent using tetra-n-butylammonium hydroxide as titrant, at 25 degrees C and under a nitrogen atmosphere. The method was found to be highly accurate and precise, having a relative standard deviation of <1.0% for all anti-inflammatory agents studied. Also, it was shown that the method could be successfully applied to the assay of commercial pharmaceuticals containing the above-mentioned anti-inflammatory agents. The validity of the method was tested by the recovery studies of standard addition to pharmaceuticals and the results were found to be satisfactory. The proposed method is simple, rapid and sufficiently precise for quality control purposes.

Simultaneous analysis of several non-steroidal anti-inflammatory drugs in human urine by high-performance liquid chromatography with normal solid-phase extraction

A practical and reproducible high-performance liquid chromatographic method using normal solid-phase extraction has been developed for the simultaneous analysis of twelve non-steroidal anti-inflammatory drugs (NSAIDs) in human urine. A urine specimen mixed with acetate buffer pH 5.0 was purified by solid-phase extraction on a Sep-Pak Silica cartridge. The analyte was chromatographed by a reversed-phase Inertsil ODS-2 column using a phosphate buffer-acetonitrile at pH 5.0 as the mobile phase, and the effluent from the column was monitored at 230 or 320 nm. Absolute recoveries were greater than 73% for all of the twelve NSAIDs. The present method enabled simple manipulation and isocratic HPLC with UV analysis as well as high sensitivity of 0.005 microg/ml for naproxen, and 0.05 microg/ml for sulindac, piroxicam, loxoprofen, ketoprofen, felbinac, fenbufen, flurbiprofen, diclofenac, ibuprofen and mefenamic acid as the quantitation limit in human urine using indomethacin as an internal standard.

Forearm vascular responses to serotonin are not mediated by products of cyclooxygenase

The involvement of cyclooxygenase-derived substances in the forearm arteriolar responses to serotonin was determined in 10 healthy male volunteers. Serotonin was infused in five incremental doses (0.003-30 micrograms min-1) for 2 min each into the brachial artery of the non-dominant forearm. Forearm blood flow (FBF) responses to each dose were measured by strain-gauge venous occlusion plethysmography. The cyclooxygenase inhibitor indomethacin (100 mg) was administered orally following the serotonin infusions. After 90 min the serotonin infusions were repeated and FBF responses measured. Serotonin caused a biphasic response with vasodilatation occurring at low doses (0.003-3 micrograms min-1, P < 0.01) and vasoconstriction occurring at the highest dose (P < 0.01). There was no significant difference in vascular response to serotonin following cyclooxygenase inhibition. In conclusion, cyclooxygenase products are not involved in the forearm vascular responses to serotonin in healthy human subjects.