Acute exposure and biomarkers assessment in rainbow trout exposed to selected pharmaceuticals.

Pharmaceuticals released from municipal effluents discharges pose a risk to aquatic organisms. The toxicity of 5 pharmaceuticals with distinct therapeutic actions were assessed in rainbow trout: olanzapine (antipsychotic), erythromycin (antibiotic), mycophenoate (immunosuppression), pinaverium (anti-inflammatory) and trazodone (sedative). Juveniles were exposed to these drugs for 96 h at concentrations between 64 µg/L up to 40 mg/L to reach lethality. Survival was determined and a suite of biomarkers was analyzed for drug biotransformation, oxidative stress/damage and metabolic activity at sublethal concentrations. The data revealed the following toxicity: olanzapine >trazodone>mycophenolate>pinaverium∼erythromycin based on mortality. The data also revealed that toxicity was associated to mass, pKa and hydrophobicity and the following sublethal effects: GST, LPO and DNA strand breaks. Pharmaceuticals with lower molecular weight, physiological pKa, moderate hydrophobicity, low biotransformation and DNA strand breaks were generally more toxic to fish. However, this should be considered as a general guide in identifying toxic pharmaceuticals in non-target organisms.

l-carnitine modulates autophagy, oxidative stress and inflammation in trazodone induced testicular toxicity.

BACKGROUND: Trazadone is an antidepressant and may affect reproductive hormones and spermatogenesis. l-carnitine is an amino acid that exhibits antioxidant actions. This study was designed to investigate the potential protective effects of l-carnitine against trazadone-induced testicular toxicity in male rats and the possible underlying mechanisms such as oxidative stress, inflammation and autophagy. METHODS: thirty-two male Wistar rats were divided randomly into four equal groups (n = 8). Testicular damage was induced by oral administration of Trazadone (TRZ, 20 mg/kg/day, p.o.) for four weeks (TRZ group). l-carnitine (LC, 200 mg/kg/day, p.o.) was applied for four weeks (LC group). LC + TRZ group administered the same doses of LC and TRZ concomitantly. The control group received distilled water (as vehicle). RESULTS: the protective treatment with LC attenuated the decline of sperm count and motility resulted from trazadone administration. Moreover, LC ameliorated trazadone increased lipid peroxidation (MDA) and reduction of total thiol and catalase activity. LC modulated the elevation in tumor necrosis factor- α (TNF-α), and increased the expression of autophagy related genes Becline-1, ATG 5 and ATG-12 in rat testes. Serum level of FSH, LH and total testosterone were increased significantly (p < 0.001) in LC + TRZ group. Histopathological findings further supported the protective effects of LC against trazadone -induced testicular injury by increasing free sperms within the lumen of spermatogenic cells and improving testicular degeneration. CONCLUSION: These findings supported the protective effects of l-carnitine on rat testes due to suppression of oxidative stress, inflammation and enhancing autophagy. l-carnitine may be recommended as adjuvant therapy to trazadone treatment.

Mutagenicity and recombinogenicity evaluation of bupropion hydrochloride and trazodone hydrochloride in somatic cells of Drosophila melanogaster.

The aim of the present study was to appraise the mutagenic and recombinogenic potential of bupropion hydrochloride (BHc) and trazodone hydrochloride (THc). We used standard (ST) and the high bioactivation (HB) crossings from Drosophila melanogaster in the Somatic Mutation and Recombination Test. We treated third-instar larvae from both crossings with different concentrations of BHc and THc (0.9375 to 7.5 mg/mL). BHc significantly increased the frequency of mutant spots in both crossings, except for the lowest concentration in the ST crossing. ST had also the mostly recombinogenic result, and in the HB, BHc was highly mutagenic. On the other hand, THc significantly increased the frequency of mutant spots in both the ST and HB crossings at all concentrations. The three initial concentrations were recombinogenic and the highest concentration was mutagenic for the THc. BHc and THc at high concentrations were toxic, even though their mutagenicity was not dose-related. THc significantly increased the frequency of mutant spots when metabolized, probably as a result of the production of 1-(3'-chlorophenyl) piperazine. BHc was essentially recombinogenic and when metabolized, it became mutagenic. THc was recombinogenic in both crossings. Further studies are needed to clarify the action mechanisms from BHc and THc.

Assessment of trazodone-induced cardiotoxicity after repeated doses in rats.

Trazodone (TRZ) is an antidepressant drug commonly used in the treatment of depression, anxiety, and insomnia. Although some studies demonstrated the adverse effects of TRZ related to cardiovascular system, the conflicting results were observed in these studies. Therefore, we aimed to investigate the cardiac adverse effects of TRZ in rats at repeated doses in our study. In accordance with this purpose, TRZ was administered orally to rats at 5, 10, and 20 mg/kg doses for 28 days. Electrocardiogram records, serum aspartate aminotransferase (AST), lactate dehydrogenase, creatine kinase-myoglobin band, cardiac troponin-T (cTn-T) levels, DNA damage in cardiomyocytes, and histologic view of heart tissues were evaluated. In addition, glutathione (GSH) and malondialdehyde (MDA) levels were measured to determine the oxidative status of cardiac tissue after TRZ administration. Heart rate was decreased, PR interval was prolonged, and QRS and T amplitudes were decreased in 20 mg/kg TRZ-administered group compared to the control group. Serum AST and cTn-T levels were significantly increased in 10 and 20 mg/kg TRZ-administered rats with respect to control rats. DNA damage was significantly increased in these groups. Additionally, degenerative histopathologic findings were observed in TRZ-administered groups. Although there was no difference in MDA levels between groups, GSH levels were significantly decreased in 10 and 20 mg/kg TRZ-administered groups compared to the control group. Our results have shown that TRZ induced cardiotoxicity in rats dose-dependently. It is assumed that oxidative stress related to GSH depletion may be accompanied by these adverse effects.

Alleviating the hepatotoxicity of trazodone via supramolecular encapsulation.

In order to develop a novel strategy to alleviate the inherent hepatotoxicity of antidepressant trazodone (TZ), Cucurbit[7]uril (CB[7]) was adopted as pharmaceutical excipients and was studied for its capability to reduce the hepatotoxicity of TZ via supramolecular encapsulation. CB[7] was found to form strong 1:1 host-guest complexes with TZ and its metabolite m-chlorophenyl piperazine (mCPP), with binding constants of 1.50 (±0.13) × 106 M-1 and 6.90 (±0.49) × 105 M-1, respectively. The supramolecular complexations were examined by 1H NMR and UV-visible spectroscopic titrations, ESI-MS and ITC. In the presence of 0.5 mM CB[7], the IC50 values of TZ and mCPP on a human normal liver cell line L02 were increased from 215.5 ±â€¯3.3 µM to 544.1 ±â€¯51.2 µM, and from 166.8 ±â€¯3.8 µM to 241.7 ±â€¯6.8 µM, respectively. Evaluation on a zebrafish model demonstrated that CB[7] (0.1 mM) significantly alleviated the TZ induced liver toxicity, as shown by the level of liver degeneration, liver size and yolk sac retention. Our study may provide a supramolecular strategy to alleviate the hepatotoxicity induced by TZ and its metabolite mCPP, and this strategy may be extendable to other drugs that have inherent hepatotoxicity or other adverse effects.

Trazodone alleviates both dyskinesia and psychosis in the parkinsonian marmoset model of Parkinson's disease.

Trazodone is a clinically available anti-depressant that exhibits affinity for serotonin 1A and 2A receptors, as well as for alpha-adrenoceptors, suggesting that it may be useful to treat L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia and psychosis that are encountered in advanced Parkinson's disease (PD). Here, we investigated the anti-dyskinetic and anti-psychotic effects of trazodone in the parkinsonian non-human primate. 6 common marmosets were rendered parkinsonian by administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Following repeated administration of L-DOPA to induce stable dyskinesia and psychosis-like behaviours (PLBs), trazodone (0.1, 1 and 10 mg/kg) or vehicle was administered in combination with L-DOPA and its effects on dyskinesia, PLBs and parkinsonism were determined. The addition of trazodone 10 mg/kg to L-DOPA reduced peak dose dyskinesia by ≈ 39% (P < 0.01) and peak dose PLBs by ≈ 17% (P < 0.01). However, parkinsonian disability was significantly worsened by trazodone 10 mg/kg (P < 0.05) and duration of anti-parkinsonian action was diminished by ≈ 21% (P < 0.05). Our results suggest that trazodone may be effective in alleviating L-DOPA-induced dyskinesia and psychosis in PD, but its deleterious effect on motor function is a concern and may limit its tolerability and usefulness in clinical settings.

Evaluation of cytogenetic and DNA damage induced by the antidepressant drug-active ingredients, trazodone and milnacipran, in vitro.

Trazodone and milnacipran are the active antidepressant drugs that are being used in the treatment of psychiatric disorders. In this study, the in vitro genotoxic effects of trazodone and milnacipran have been determined in human peripheral blood lymphocytes by using chromosomal aberrations (CAs), sister chromatid exchanges (SCEs), micronuclei (MN), and comet assays. 3.13; 6.25; 12.50; 25.00; 50.00; and 75.00 µg/mL concentrations of trazodone and 2.50; 5.00; 10.00; 20.00; 30.00; and 40.00 µg/mL concentrations of milnacipran were used. Trazodone and milnacipran significantly increased the frequency of CAs and SCEs compared with the control. Both of the active ingredients raised the MN frequency in a dose-dependent manner. Mitotic index was significantly decreased, but replication and nuclear division indices were not affected at all treatments. Trazodone was statistically increased the mean comet tail intensity, tail length, and tail moment at three concentrations (6.25; 12.50; and 25.00 µg/mL) compared with control. Two highest concentrations (50 and 75 µg/mL) of trazodone were toxic in the comet assay. Milnacipran increased the comet tail intensity, tail length, and tail moment at all concentrations. It is concluded that trazodone and milnacipran have clastogenic, mutagenic, and cytotoxic effects on human lymphocytes in vitro.

Cellular mechanisms for trazodone-induced cardiotoxicity.

The second-generation selective 5-HT2 receptor antagonists and reuptake inhibitors (SARIs) class antidepressants are known to have fewer cardiovascular side effects than the older ones. However, several case reports showed that trazodone, one of the second-generation SARIs, induces QT prolongation, cardiac arrhythmia, and ventricular tachycardia. Although these clinical cases suggested trazodone-induced cardiotoxicity, the toxicological actions of trazodone on cardiac action potentials (APs) beyond the human ether-a-go-go related gene (hERG) remain unclear. To elucidate the cellular mechanism for the adverse cardiac effects of trazodone, we investigated its effects on cardiac APs and ion channels using whole-cell patch clamp techniques in human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and transiently transfected human embryonic kidney cells (HEK293) with cardiac ion channel complementary DNA. Trazodone dose-dependently decreased the maximum upstroke velocity (Vmax) and prolonged the AP duration, inducing early after depolarizations at 3 and 10 µM that triggered ventricular arrhythmias in hiPSC-CMs. Trazodone also inhibited all of the major ion channels (IKr, IKs, INa, and ICa), with an especially high inhibitory potency on hERG. These data indicate that the prolonged AP duration and decreased Vmax due to trazodone are mainly the result of hERG and sodium ion inhibition, and its inhibitory effects on cardiac ion channels can be exhibited in hiPSC-CMs.

A comparison of drug-induced cardiotoxicity in rat embryos cultured in human serum or protein free media.

INTRODUCTION: Although much reproductive toxicology research is performed in live animals there is increasing use of in vitro techniques primarily to identify potential hazards with human exposure. As many in vitro studies are undertaken using protein free media, the standard protocol is to compare the effect concentration determined in vitro with the predicted therapeutic free plasma concentration in humans. The aim of the present study was to test this rationale by comparing the effect of a small number of therapeutic drugs on heart rate of rodent embryos cultured in human sera or protein free serum. METHODS: Whole rat embryos were cultured in protein-free media or human serum to which drugs (amiodarone, citalopram, dofetilide, haloperidol, paroxetine, quetiapine, or trazodone) known to induce embryonic bradycardia were added. Embryonic heart rate was observed before and after addition of drugs. RESULTS: Most of the tested drugs (5/7) caused a greater decrease in embryonic heart rate in human sera than predicted based on the protein binding of the drug. DISCUSSION: The results suggest that there is less unbound drug in the protein free media and/or more unbound drug in the human sera than predicted. Variables such as saturated protein binding and pH cannot fully explain our results. Since the results did not validate the original rationale, reproductive toxicity results obtained using protein free in vitro techniques may not have the large safety factors predicted on the basis of protein binding.

Mechanisms of trazodone-induced cytotoxicity and the protective effects of melatonin and/or taurine toward freshly isolated rat hepatocytes.

It has been reported that the bioactive intermediate metabolites of trazodone might cause hepatotoxicity. This study was designed to investigate the exact mechanism of hepatocellular injury induced by trazodone as well as the protective effects of taurine and/or melatonin against this toxicity. Freshly isolated rat hepatocytes were used. Trazodone was cytotoxic and caused cell death with LC50 of 300 µm within 2 h. Trazodone caused an increase in reactive oxygen species (ROS) formation, malondialdehyde accumulation, depletion of intracellular reduced glutathione (GSH), rise of oxidized glutathione disulfide (GSSG), and a decrease in mitochondrial membrane potential, which confirms the role of oxidative stress in trazodone-induced cytotoxicity. Preincubation of hepatocytes with taurine prevented ROS formation, lipid peroxidation, depletion of intracellular reduced GSH, and increase of oxidized GSSG. Taurine could also protect mitochondria against trazodone-induced toxicity. Administration of melatonin reduced the toxic effects of trazodone in isolated rat hepatocytes.

Effect of 70-nm silica particles on the toxicity of acetaminophen, tetracycline, trazodone, and 5-aminosalicylic acid in mice.

Exposure to nano-sized particles is increasing because they are used in a wide variety of industrial products, cosmetics, and pharmaceuticals. Some animal studies indicate that such nanomaterials may have some toxicity, but their synergistic actions on the adverse effects of drugs are not well understood. In this study, we investigated whether 70-nm silica particles (nSP70), which are widely used in cosmetics and drug delivery, affect the toxicity of a drug for inflammatory bowel disease (5-aminosalicylic acid), an antibiotic drug (tetracycline), an antidepressant drug (trazodone), and an antipyretic drug (acetaminophen) in mice. Co-administration of nSP70 with trazodone did not increase a biochemical marker of liver injury. In contrast, co-administration increased the hepatotoxicity of the other drugs. Co-administration of nSP70 and tetracycline was lethal. These findings indicate that evaluation of synergistic adverse effects is important for the application of nano-sized materials.

In vitro assessment of mitochondrial dysfunction and cytotoxicity of nefazodone, trazodone, and buspirone.

Mitochondrial toxicity is increasingly implicated in a host of drug-induced organ toxicities, including hepatotoxicity. Nefazodone was withdrawn from the U.S. market in 2004 due to hepatotoxicity. Accordingly, we evaluated nefazodone, another triazolopyridine trazodone, plus the azaspirodecanedione buspirone, for cytotoxicity and effects on mitochondrial function. In accord with its clinical disposition, nefazodone was the most toxic compound of the three, trazodone had relatively modest effects, whereas buspirone showed the least toxicity. Nefazodone profoundly inhibited mitochondrial respiration in isolated rat liver mitochondria and in intact HepG2 cells where this was accompanied by simultaneous acceleration of glycolysis. Using immunocaptured oxidative phosphorylation (OXPHOS) complexes, we identified Complex 1, and to a lesser amount Complex IV, as the targets of nefazodone toxicity. No inhibition was found for trazodone, and buspirone showed 3.4-fold less inhibition of OXPHOS Complex 1 than nefazodone. In human hepatocytes that express cytochrome P450, isoform 3A4, after 24 h exposure, nefazodone and trazodone collapsed mitochondrial membrane potential, and imposed oxidative stress, as detected via glutathione depletion, leading to cell death. Our results suggest that the mitochondrial impairment imposed by nefazodone is profound and likely contributes to its hepatotoxicity, especially in patients cotreated with other drugs with mitochondrial liabilities.

Inhibition of hepatobiliary transport as a predictive method for clinical hepatotoxicity of nefazodone.

Treatment with the antidepressant nefazodone has been associated with clinical idiosyncratic hepatotoxicty. Using membranes expressing human bile salt export pump (BSEP), human sandwich hepatocytes, and intact rats, we compared nefazodone and its marketed analogs, buspirone and trazodone. We found that nefazodone caused a strong inhibition of BSEP (IC(50) = 9 microM), inhibition of taurocholate efflux in human hepatocytes (IC(50) = 14 microM), and a transient increase in rat serum bile acids 1 h after oral drug administration. Buspirone or trazodone had no effect on biliary transport system. Nefazodone produced time- and concentration-dependent toxicity in human hepatocytes with IC(50) = 18 microM and 30 microM measured by inhibition of protein synthesis after 6 h and 24 h incubation, respectively. Toxicity was correlated with the amount of unmetabolized nefazodone. Partial recovery in toxicity by 24 h has been associated with metabolism of nefazodone to sulfate and glucuronide conjugates. The saturation of nefazodone metabolism resulted in sustained decrease in protein synthesis and cell death at 50 microM. The toxicity was not observed with buspirone or trazodone. Addition of 1-aminobenzotriazole (ABT), an inhibitor of CYP450, resulted in enhancement of nefazodone toxicity at 10 microM and was associated with accumulation of unmetabolized nefazodone. In human liver microsomes, ABT also prevented metabolism of nefazodone and formation of glutathione conjugates. We suggest that inhibition of bile acid transport by nefazodone is an indicator of potential hepatotoxicity. Our findings are consistent with the clinical experience and suggest that described methodology can be applied in the selection of nonhepatotoxic drug candidates.

Effects of the antidepressant trazodone, a 5-HT 2A/2C receptor antagonist, on dopamine-dependent behaviors in rats.

RATIONALE: 5-Hydroxytryptamine, via stimulation of 5-HT 2C receptors, exerts a tonic inhibitory influence on dopaminergic neurotransmission, whereas activation of 5-HT 2A receptors enhances stimulated DAergic neurotransmission. The antidepressant trazodone is a 5-HT 2A/2C receptor antagonist. OBJECTIVES: To evaluate the effect of trazodone treatment on behaviors dependent on the functional status of the nigrostriatal DAergic system. METHODS: The effect of pretreatment with trazodone on dexamphetamine- and apomorphine-induced oral stereotypies, on catalepsy induced by haloperidol and apomorphine (0.05 mg/kg, i.p.), on ergometrine-induced wet dog shake (WDS) behavior and fluoxetine-induced penile erections was studied in rats. We also investigated whether trazodone induces catalepsy in rats. RESULTS: Trazodone at 2.5-20 mg/kg i.p. did not induce catalepsy, and did not antagonize apomorphine (1.5 and 3 mg/kg) stereotypy and apomorphine (0.05 mg/kg)-induced catalepsy. However, pretreatment with 5, 10 and 20 mg/kg i.p. trazodone enhanced dexamphetamine stereotypy, and antagonized haloperidol catalepsy, ergometrine-induced WDS behavior and fluoxetine-induced penile erections. Trazodone at 30, 40 and 50 mg/kg i.p. induced catalepsy and antagonized apomorphine and dexamphetamine stereotypies. CONCLUSIONS: Our results indicate that trazodone at 2.5-20 mg/kg does not block pre- and postsynaptic striatal D2 DA receptors, while at 30, 40 and 50 mg/kg it blocks postsynaptic striatal D2 DA receptors. Furthermore, at 5, 10 and 20 mg/kg, trazodone blocks 5-HT 2A and 5-HT 2C receptors. We suggest that trazodone (5, 10 and 20 mg/kg), by blocking the 5-HT 2C receptors, releases the nigrostriatal DAergic neurons from tonic inhibition caused by 5-HT, and thereby potentiates dexamphetamine stereotypy and antagonizes haloperidol catalepsy.

Priapism induced by chlorpromazine and trazodone: mechanism of action.

To investigate the mechanism of drug-induced priapism, we gave the antipsychotic agent chlorpromazine and the antidepressant trazodone to 14 dogs by intravenous and intracorporeal injection. Bilateral intracorporeal pressure, blood flow within the internal pudendal artery, and systemic blood pressure were monitored. Venous outflow restriction was evaluated by continuous saline infusion of the corpus cavernosum with the infrarenal aorta clamped. When delivered by intracorporeal injection, both drugs induced erection in a manner similar to that of intracorporeal injection of papaverine. Internal pudendal arterial flow increased slightly at the beginning of tumescence, and excellent venous restriction occurred. Intravenous injection, however, could neither induce an erection nor facilitate an erection after sub-threshold neurostimulation. We believe that the alpha-adrenergic antagonist properties of chlorpromazine and trazodone probably cause priapism by local action.

Electrophysiological and haemodynamic changes with trazodone, amitriptyline and placebo in depressed out-patients.

Fourteen out-patients with major depressive disorder completed a double-blind, randomized, parallel group study using trazodone (n = 6), amitriptyline (n = 5) and matching placebo (n = 3). The average daily doses used were 223 mg and 95.3 mg for trazodone and amitriptyline, respectively, over the 28-day treatment period. Cardiovascular function was monitored with high speed ECG and by determining systolic time intervals. No significant effects of either drug on supine or standing blood pressure were demonstrated. Trazodone increased QTc on Day 1 only, and reduced heart rate and increased the PR interval on Day 15; these effects had disappeared by Day 29. Amitriptyline markedly increased heart rate, PR interval and QTc, and reduced T wave amplitude on Days 15 and 29. Trazodone had no consistent effect on systolic time intervals except to increase the LVET index, whereas amitriptyline increased both PEP index and PEP/LVET ratio on Days 15 and 29. It is concluded that amitriptyline had a much more marked effect on cardiac function than did trazodone.