Gastrointestinal safety of coxibs: systematic review and meta-analysis of observational studies on selective inhibitors of cyclo-oxygenase 2

Prior meta-analyses have shown a higher gastrointestinal risk of nonselective NSAIDs versus placebo and a lower gastrointestinal risk of coxibs versus nonselective NSAIDs. However, the available data about gastrointestinal risk for coxibs versus placebo are scarce. The aim of this study was to review the current evidence on the use of coxibs and to evaluate the risk of gastrointestinal adverse outcomes (GAO) associated with coxibs versus nonexposed. Search was conducted on PubMed and Embase databases. We selected cohort observational, case-control, nested case-control and case-crossover studies that reported the risk of GAO associated with coxibs versus nonexposed as relative risk (RR), odds ratio (OR), hazard ratio (HR) or incidence rate ratio (IRR). It was estimated the pooled RR and the 95% confidence interval (CI) for coxibs both individually and as a whole by the DerSimonian and Laird method. Twenty-eight studies met inclusion criteria. Overall, coxibs were associated with a significant increment in the risk of GAO [RR 1.64 (95% CI 1.44-1.86)]. The analysis by individual drugs showed that etoricoxib [RR 4.85 (95% CI 2.64-8.93)] presented the highest gastrointestinal risk, followed by rofecoxib [RR 2.02 (95% CI 1.56-2.61)] and celecoxib [RR 1.53 (95% CI 1.19-1.97)]. Gastrointestinal risk was also high for the subgroups aged <65 years and low-dose coxibs. The use of coxibs is associated with a statistically significant increased risk of GAO, which would be high even for low-dose coxibs and <65-year-old subgroups. The risk would be higher for etoricoxib than for celecoxib and rofecoxib.

[Impact of the spanish pharmacovigilance system recommendations on the publication of cases of adverse drug reaction]

OBJECTIVE

To assess the impact of the recommendations that, the Technical Committee of the Spanish Pharmacovigilance System sent, in 2004, to the editors of Spanish medical journals on the minimum information required for publication of adverse drug reaction case reports.

DESIGN

Observational study.

SETTING

National suspected adverse drug reactions database (FEDRA).

PARTICIPANTS

Published adverse drug reaction reports registered in FEDRA, published in the years before (2003) and after (2005) the recommendations were issued.

MAIN MEASUREMENTS

The following data elements were analysed: sex, age, dose, disease treated with the suspected drug, length of treatment and adverse drug reaction, temporal sequence, withdrawal effect, and alternative causes. The results of the 2 years were compared.

RESULTS

The information in the case reports published between years 2003 and 2005 was not significantly different. The data elements more often incomplete were dose, length of treatment, as well as length of adverse reaction. Approximately one third of the published case reports included full information.

CONCLUSIONS

There seems to be a need to improve the data elements content of published adverse drug reactions case reports, so that such documentation can contribute to improve the assessment of alert signals.

STZ-induced diabetes in mice and heme pathway enzymes. Effect of allylisopropylacetamide and alpha-tocopherol

A frequent coexistence of diabetes and porphyria disease has been reported. Under normal conditions, porphyrin biosynthesis is well regulated to only form the amount of heme required for the synthesis of the various hemoproteins. The activity of some heme enzymes and rhodanese in streptozotocin (STZ) induced diabetic mice and in allylisopropylacetamide (AIA) induced experimental acute porphyria mice has been examined. The role of alpha-tocopherol (alpha-T), reported to prevent protein glycation in vitro, has also been investigated. AIA induced hepatic delta-aminolevulinic acid synthetase (ALA-S) activity in control animals but was ineffective in the diabetic group. alpha-Tocopherol did not modify ALA-S activity in either group. delta-Aminolevulinic acid dehydratase (ALA-D) and deaminase activities were significantly diminished both in liver and blood of diabetic animals. alpha-Tocopherol prevented inhibition of ALA-D, deaminase and blood rhodanese activities in diabetic animals but alpha-tocopherol by itself did not affect the basal levels of the enzymes studied. The potential use of alpha-tocopherol to prevent late complications of diabetes, including the onset of a porphyria like syndrome is considered.

Rhodanese and ALA-S in mammary tumor and liver from normal and tumor-bearing mice

1. Basal levels and allyl-isopropylacetamide (AIA) or veronal induced levels of delta-amino-levulinate synthetase (ALA-S), cytoplasmic and mitochondrial rhodanese were determined in tumor (T) and liver of both normal mice (NM) and T-bearing mice (TBM). 2. Rhodanese tumoral mitochondrial levels were higher than the hepatic normal mitochondrial fraction, while the cytoplasmic activity was nearly equal in all sources. 3. In neither case was the activity of tumoral ALA-S and rhodanese altered by any of the porphyrinogenic drugs. 4. Mitochondrial and cytoplasmic rhodanese activity was also measured in tumor and liver of TBM at different intervals after transplantation. We concluded that the behaviour of rhodanese is a property inherent to the tissue and not one attained with time.

The effect of griseofulvin on the heme pathway--II. An exhaustive analysis during short and long-term challenge

1. A clear biphasic response of the enzyme activities as a function of intoxication time due to the topical cutaneous griseofulvin treatment was observed. 2. The initial acute induction of ALA-S activity would be due to depletion of free heme in the regulatory pool caused by cytochrome P 450 destruction. 3. The second induction peak, would be due to less heme formation, secondary to the ferrochelatase inhibition, as expected for the erythropoietic protoporphyria model. 4. The biphasic response of hepatic ALA-D and PBGase activities would be related to ALA-S activity changes and the subsequent augmented available substrates. 5. Endogenous liver porphyrin distribution in cytosolic, mitochondrial and nuclear fractions was investigated. 6. The in vitro biosynthesis of porphyrins confirmed both the biphasic model and the hepatic porphyrins subcellular distribution. 7. Two mechanisms to explain the action of griseofulvin at shorter and longer times of intoxication are proposed.