SSRIs antidepressants in marine mussels from Atlantic coastal areas and human risk assessment.

Selective serotonin reuptake inhibitors (SSRIs) are among the most prescribed antidepressants nation and worldwide. Their presence in the aquatic environment is known, causing growing pressures in heavily populated coastal areas. For instance, disruption of invertebrate endocrine systems has been described. Since discrete seawater sampling may not be suitable to evaluate such environmental risk, we aimed to assess SSRIs and metabolites in wild Mytilus galloprovincialis, and assess risk to human health. A total of 1225 mussels were sampled during one year along the Portuguese Atlantic coast. Each freeze-dried pool of 25 specimens was analyzed, in duplicate, by solid phase extraction (SPE) and liquid chromatography with tandem mass spectrometry (LC-MSn). Approximately 70% of the samples were contaminated with at least one, and up to 4 from the 7 targeted compounds. The cumulative SSRIs and metabolites content in mussels ranged between 3.17 and 33.93ngg-1 dry weight, in a mean level of 14.68±9.69ngg-1. Norfluoxetine was the most recurring SSRI and the one with the highest mean concentration, 13.52ngg-1. Although some differences were found between different sampling periods and locations, those were not statistically significant (p>0.05) and no correlation was found between wet weight and mean contamination levels. Regarding risk to human health following consumption of these filter-feeders, when considering the average sample contamination of positive samples and the average Portuguese and European consumption, the ratio between the estimated daily intake (EDI) and the acceptable daily intake (ADI) ranged from 0.45 to 5.50%, and from 1.60 to 19.41%, respectively. Therefore, although the resultant risk is lower for the Portuguese consumer than for the average EU consumer, apparently, no appreciable risk to human health is expected.

Is exposure temperature a confounding factor for the assessment of reproductive parameters of New Zealand mudsnails Potamopyrgus antipodarum (Gray)?

Potamopyrgus antipodarum is a promising test organism often used in ecotoxicology testing, both in laboratory and in field exposure experiments. It has been recommended for use in the development of an OECD reproduction test. However, exposure temperature is important to take into account when assessing reproduction and related biomarkers, because it can act as a confounding factor inducing variability in physiological values. The effect of three environmentally realistic exposure temperatures (8, 16 and 24°C) was examined with respect to the number of neonates born, the number of embryos in the brood pouch and the duration of embryonic development. We also measured additional markers likely to be related to the modulation of reproductive performance, such as vertebrate-like sex steroid, energy status and vitellin-like proteins. Exposure temperature had a significant effect on reproduction in P. antipodarum, on both the duration of embryonic development and the quantity of embryos and neonates. The consequences of these observations must not be neglected when using this species in laboratory and field experiments. This study determined suitable temperatures for field experiments and a mean duration for embryonic development independent of temperature. In addition to steroid levels, energy status and Vn-like protein levels were only slightly modified by exposure temperature between 8 and 24°C. Thus, they can be easily implemented and their variations related to anthropogenic factors during field exposure of mudsnails.

Environmental risk assessment of three selective serotonin reuptake inhibitors in the aquatic environment: a case study including a cocktail scenario.

We present an environmental risk assessment of three selective serotonin reuptake inhibitors (SSRIs; citalopram, sertraline, and fluoxetine) in the aquatic environment based on two case scenarios. Abiotic and biotic degradation experiments and sorption estimates were used to predict environmental concentrations of three SSRIs from the wastewater of two psychiatric hospitals, the primary sector, and wastewater entering and leaving wastewater treatment plants (WWTPs). Assuming a sewage treatment retention time of 8 h, abiotic degradation was low, for all three SSRIs inhibitors, ranging between 0 and 2% for hydrolysis and 0 and 6% for photolysis. The biodegradation was also slow, ranging from 0 to 3% within an 8-h period. In untreated sewage, citalopram (CIT) and sertraline (SER) concentrations may be high enough to exert effects on the aquatic biota (CIT: 0.19-10.3 µg/L; SER: 0.14-17.1 µg/L). Removal of the pharmaceuticals is due primarily to sorption in the WWTP. Sertraline was estimated to have the highest concentrations in the sewage effluents, 4.4 and 19.9 ng/L for the two cases, respectively. In treated wastewater, individual SSRI concentrations are probably too low to exert effects on biota. By using concentration addition, a cocktail exposure scenario was estimated. The predicted concentration in the biota calculated from the cocktail effect was 0.05 and 0.16 nmol/g for the two cases, respectively, and SER was found to give the highest contribution to this cocktail effect. The results indicate that the concentrations in the wastewater effluents are one to two orders of magnitude lower than the concentrations likely to cause an effect in the aquatic biota.

Assessment of potential immunotoxic effects caused by cypermethrin, fluoxetine, and thiabendazole using heat shock protein 70 and interleukin-1ß mRNA expression in the anuran Xenopus laevis.

The current study describes the effect of cypermethrin, fluoxetine, and thiabendazole, at environmentally relevant concentrations, on the expression of heat shock protein 70 (HSP70) and interleukin 1ß (IL-1ß), using Xenopus laevis larvae as animal model. Cytokines and interleukins are considered good predictors of the immunotoxic potential of xenobiotics. Tadpoles at stage 47 (normal tables of X. laevis) were exposed under static conditions to: 0.3 and 30 µg/L fluoxetine, 0.7 µg/L thiabendazole, and 0.24 µg/L cypermethrin. The effects were evaluated at 7, 24, and 72 h, and 6 and 9 d. Randomly chosen tadpoles were used as genetic material for detection of hsp70 and IL-1ß mRNA induction through reverse transcription PCR. Tadpoles exposed to 30 µg/L fluoxetine showed mRNA expression of both genes at all exposure times, whereas at 0.3 µg/L a peak response for hsp70 was observed after 24 h, and the increase in IL-1ß mRNA was statistically significant with respect to the control 72 h after exposure. Thiabendazole induced a high expression of mRNA for both hsp70 and IL-1ß at all exposure times. Cypermethrin increased the hsp70 mRNA levels, with a peak at 24 h, and provoked high expression of IL-1ß mRNA at all exposure times. Considering the relationship between HSP70 and IL-1ß and their involvement (mainly of IL-1ß) in immune responses, certain changes observed in their expression could be considered warning indicators of potential immunotoxic effects of these substances on Xenopus.

Environmental risk assessment for the serotonin re-uptake inhibitor fluoxetine: Case study using the European risk assessment framework.

The serotonin re-uptake inhibitor fluoxetine was selected for an environmental risk assessment, using the most recent European guideline (EMEA 2006) within the European Union (EU)-funded Environmental Risk Assessment of Pharmaceuticals (ERAPharm) project due to its environmental persistence, acute toxicity to nontarget organisms, and unique pharmacokinetics associated with a readily ionizable compound. As a widely prescribed psychotropic drug, fluoxetine is frequently detected in surface waters adjacent to urban areas because municipal wastewater effluents are the primary route of entry to aquatic environments. In Phase I of the assessment, the initial predicted environmental concentration of fluoxetine in surface water (initial PEC(SW)) reached or exceeded the action limit of 10 ng/L, when using both a default market penetration factor and prescription data for Sweden, Germany, and the United Kingdom. Consequently, a Phase II risk assessment was conducted in which green algae were identified as the most sensitive species with a NOEC of <0.6 microg/L. From this value, a predicted no effect concentration for surface waters (PNEC(SW)) of 0.012 microg/L was derived. The PEC/PNEC ratio was above the trigger value of 1 in worst-case exposure scenarios indicating a potential risk to the aquatic compartment. Similarly, risks of fluoxetine for sediment-dwelling organisms could not be excluded. No risk assessment was conducted for the terrestrial compartment due to a lack of data on effects of fluoxetine on soil organisms. The need for a separate risk assessment for the main metabolite of fluoxetine, norfluoxetine, was not conducted because of a lack of fate and effect studies. Based on published data, fluoxetine and norfluoxetine appeared to have a low to moderate bioaccumulation potential, which should be confirmed in formal studies according to OECD guidelines. Exposure assessments for fluoxetine according to the current framework rely heavily on K(OC) and K(OW) values. This approach is problematic, because fluoxetine is predominantly a cationic substance at environmental pH values. Consequently, the fate of fluoxetine (and other ionic substances) cannot be predicted using partition coefficients established for nonionic compounds. Further, published estimates for partition coefficients of fluoxetine vary, resulting in considerable uncertainties in both the exposure and environmental risk assessments of fluoxetine.

Quality assessment of fluoxetine and fluvoxamine pharmaceutical formulations purchased in different countries or via the Internet by 19F and 2D DOSY 1H NMR.

A simple and selective (19)F NMR method has been validated for the quantitation of fluoxetine (FLX) and fluvoxamine (FLV) in methanol solutions and in human plasma and urine. The regression equations for FLX and FLV showed a good linearity in the range of 1.4-620 microg mL(-1) (3.3 x 10(-6)-1.8 x 10(-3) mol L(-1)) with a limit of detection of approximately 0.5 microg mL(-1) (1.3 x 10(-6) mol L(-1)) and a limit of quantification of approximately 2 microg mL(-1) (4.6 x 10(-6) mol L(-1)). The precision of the assay depends on the concentrations and is comprised between 1.5 and 9.5% for a range of concentrations between 1.2 x 10(-3) and 3.2 x 10(-6) mol L(-1). The accuracy evaluated through recovery studies ranged from approximately 96 to 103% in methanol solutions and in urine, and from approximately 93 to 104% in plasma, with standard deviations <7.5%. The low sensitivity of the method precludes its use for the assay of these antidepressants in biofluids at least at therapeutic doses as the ranges of FLX and FLV plasma levels are 0.15-0.5 microg mL(-1) and 0.15-0.25 microg mL(-1), respectively. The method was applied successfully to the determination of FLX and FLV contents in pharmaceutical samples (brand-named and generic) purchased in several countries or via the Internet. All the commercial formulations contain the active ingredient in the range 94-103% of stated concentration. A "signature" of the formulations (solid and liquid) was obtained with 2D Diffusion-Ordered SpectroscopY (DOSY) (1)H NMR which allowed the characterisation of the active ingredient and excipients present in the formulations studied. Finally, the DOSY separation of FLX and FLV whose molecular weights are very close was obtained by using beta-cyclodextrin as host-guest complexing agent.

Exposure assessment and microcosm fate of selected selective serotonin reuptake inhibitors.

The exposure and fate of selective serotonin reuptake inhibitors (SSRIs) was evaluated using modeled predicted environmental concentrations (PECs) according to the U.S. and the European Union (EU) guidelines and microcosm model ecosystems. According to the U.S. guidance, crude environmental introduction concentrations, the only SSRI that would require environmental assessment would be sertraline. However, the more conservative EU draft guidance PEC would require further assessment of all five SSRIs. Refined PECs developed using the U.S. and the EU guidelines along with estimates of removal by sewage treatment and receiving water dilution factors indicate that the U.S. methodology corresponds better to MEC data determined in the U.S. and Canada. Worst-case (99th centile) PECs for citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline were 30, 19, 30, 65, and 122 ng/L, respectively, using the U.S. methodology and 142, 182, 841, 144, and 575 ng/L, respectively, using the EU draft methodology. The dissipation of fluoxetine and fluvoxamine from the water column in aquatic microcosms was best described using a two-compartment model while sertraline followed a one-compartment model. Fluoxetine and fluvoxamine water concentrations initially dissipated with first phase half-lives of 3.8 and 1.8 days, respectively, but levelled off at concentrations around 10 microg/L with second phase half-lives of 76.7 and 59.3 days, respectively, not including those estimated as infinity. Sertraline dissipation tended toward the detection limit with a half-life of 3.4 days. Fluoxetine was found to be the most persistent followed by fluvoxamine and sertraline. Estimated log(K(OC)) values for all SSRIs were >4.3 indicating that SSRIs are expected to adsorb to sediment or sludge. Partitioning into other environmental compartments such as this may act as a reservoir from which SSRIs may be re-released into surface waters and indicates the potential susceptibility of benthos.

Spectrophotometric determination of fluoxetine hydrochloride in bulk and in pharmaceutical formulations.

Two new rapid, sensitive and economical spectrophotometric methods are described for the determination of fluoxetine hydrochloride in bulk and in pharmaceutical formulations. Both methods are based on the formation of a yellow ion-pair complex due to the action of methyl orange (MO) and thymol blue (TM) on fluoxetine in acidic (pH 4.0) and basic (pH 8.0) medium, respectively. Under optimised conditions they show an absorption maxima at 433 nm (MO) and 410 nm (TB), with molar absorptivities of 2.12 x 10(-4) and 4.207 x 10(-3) l mol(-1) cm(-1) and Sandell's Sensitivities of 1.64 x 10(-2) and 0.082 microg cm(-2) per 0.001 absorbance unit for MO and TB, respectively. The colour is stable for 5 min after extraction. In both cases Beer's Law is obeyed at 1-20 microg mol(-1) with MO and 4-24 microg mol(-1) with TB. The proposal method was successfully extended to pharmaceutical preparations capsules. The results obtained by both the agreement and E.P. (3rd edition) were in good agreement and statistical comparison by Student's t-test and variance ratio F-test showed no significant difference in the three methods.