Pharmacobezoar-Related Fatalities: A Case Report and a Review of the Literature.

ABSTRACT: Pharmacobezoars develop after an acute overdose or during routine drug administration. Here, the authors present a case of fatal multidrug overdose involving a 62-year-old woman. Her usual treatment included tramadol extended-release, citalopram, and mirtazapine. Furthermore, she self-medicated and misused her husband's medications. The autopsy revealed the presence of a voluminous medication bezoar in the stomach. No mechanical complication was noted. Toxicologic analyses were performed using gas chromatography with flame ionization detection, liquid chromatography with diode array detection, gas chromatography with mass spectrometry detection, and liquid chromatography coupled to tandem mass spectrometry. Tramadol (34,000 mcg/L), O-desmethyltramadol (2200 mcg/L), propranolol (6000 mcg/L), bromazepam (2500 mcg/L), zopiclone (1200 mcg/L), and citalopram (700 mcg/L) were identified in femoral blood at toxic concentrations. Interestingly, the femoral blood and vitreous humor concentration ratio was approximately 0.7. Furthermore, an English exhaustive literature search was performed using several different electronic databases without any limiting period to identify published pharmacobezoar-related fatalities. Seventeen publications were identified reporting a total of 19 cases. Decedents' mean age was 47.6 years [0.8-79] and a clear female predominance emerged. Several drugs were involved in pharmacobezoar formation. Death was attributed to drug toxicity in 13 cases, and to mechanical complications and/or sepsis in 4 cases. A mixed cause of death was reported in 2 cases. Although rare, pharmacobezoars remain potentially lethal and raise challenges in therapeutic management.

Maintenance of mitochondrial function by sinapic acid protects against tramadol-induced toxicity in isolated mitochondria obtained from rat brain.

It is reported that tramadol can induce neurotoxic effects with the production of DNA damage, mitochondrial dysfunction, and oxidative stress. The current study aimed to evaluate the potential role of mitochondrial impairment in the pathogenesis of tramadol-induced neurotoxicity, and protective effect of sinapic acid (SA) against it in isolated mitochondria from rat brain. Mitochondria were isolated and were incubated with toxic concentrations (100 µM) of tramadol and then cotreated with tramadol + SA (10, 50, and 100 µM). Biomarkers of mitochondrial toxicity including succinate dehydrogenases (SDH) activity, reactive oxygen species (ROS), lipid peroxidation (LPO), mitochondrial membrane potential (MMP), GSH depletion, and mitochondrial swelling were assessed. Our results showed a significant decrease in SDH activity, and a significant increase in ROS, LPO, GSH depletion, MMP collapse, and mitochondrial swelling was detected in tramadol group. We observed that 50 and 100 µM SA cotreatment for 1 h efficiently ameliorated tramadol-caused damage in mitochondrial dysfunction, accumulation of ROS, LPO, GSH depletion, depolarization of mitochondrial membrane potential, and mitochondrial swelling. These data suggest that mitochondrial impairment and oxidative stress are mechanisms involved in the pathogenesis of tramadol-induced neurotoxicity. Also, results indicate that SA antagonizes against tramadol-induced mitochondrial toxicity and suggest SA may be a preventive/therapeutic agent for tramadol-induced neurotoxicity complications.

Modulatory effects of Cannabis sativa co-administration with tramadol and codeine on cognitive function in male rats.

Most teenagers mix up various psychoactive cocktail substances in combinations to get intoxicated. The role of the mixture combination of codeine (CDE), tramadol (TMD), and Cannabis sativa (CNB) on brain cognition, purinergic, cholinergic, and antioxidant enzyme activities remains unknown. This study sought to assess the mechanism of action of combinations of CDE+ TMD+ CNB on the function and activities of the brain of male Wistar rats. Forty-eight male Wistar rats were divided into 8 groups, n = 6. Group 1 served as a control, groups 2, 3, and 4 were exposed to CDE (2 mg/kg bw), TMD (10 mg/kg bw), and CNB (200 mg/kg bw), while groups 5, 6, 7, and 8 were co-administered with CDE+TMD, CNB+ TMD, CNB+CDE, and CNB+TMD+CDE orally for 28 days. This study revealed the effect of prolonged administration of CNB, TMD, and CDE on the suppression of cognitive function, acetyl-cholinesterase (AChE), butyl-cholinesterase (BChE), monoamine oxidase (MAO) enzyme activities, and antioxidant enzyme activities in rats' brains when compared against control rats (P < 0.05). However, the activities of ectonucleosides (NTPdase), adenosine deaminase (ADA), and malondialdehyde levels produced in the brain of rats were significantly elevated (P < 0.05). This study reported the mechanism behind the neurotoxicity of CNB, TMD, and CDE on rats' cognitive, cholinergic, purinergic, and antioxidant enzymes as a consequence of the drastic reduction in cholinesterase enzyme activities leading to neurotransmitter poisoning.

Neuroprotective potential of trimetazidine against tramadol-induced neurotoxicity: role of PI3K/Akt/mTOR signaling pathways.

Tramadol (TRA) causes neurotoxicity whereas trimetazidine (TMZ) is neuroprotective. The potential involvement of the PI3K/Akt/mTOR signaling pathway in the neuroprotection of TMZ against TRA-induced neurotoxicity was evaluated. Seventy male Wistar rats were divided into groups. Groups 1 and 2 received saline or TRA (50 mg/kg). Groups 3, 4, and 5 received TRA (50 mg/kg) and TMZ (40, 80, or 160 mg/kg) for 14 days. Group 6 received TMZ (160 mg/kg). Hippocampal neurodegenerative, mitochondrial quadruple complex enzymes, phosphatidylinositol-3-kinases (PI3Ks)/protein kinase B levels, oxidative stress, inflammatory, apoptosis, autophagy, and histopathology were evaluated. TMZ decreased anxiety and depressive-like behavior induced by TRA. TMZ in tramadol-treated animals inhibited lipid peroxidation, GSSG, TNF-α, and IL-1ß while increasing GSH, SOD, GPx, GR, and mitochondrial quadruple complex enzymes in the hippocampus. TRA inhibited Glial fibrillary acidic protein expression and increased pyruvate dehydrogenase levels. TMZ reduced these changes. TRA decreased the level of JNK and increased Beclin-1 and Bax. TMZ decreased phosphorylated Bcl-2 while increasing the unphosphorylated form in tramadol-treated rats. TMZ activated phosphorylated PI3Ks, Akt, and mTOR proteins. TMZ inhibited tramadol-induced neurotoxicity by modulating the PI3K/Akt/mTOR signaling pathways and its downstream inflammatory, apoptosis, and autophagy-related cascades.

Carbamazepine, venlafaxine, tramadol, and their main metabolites: Toxicological effects on zebrafish embryos and larvae.

Pharmaceutical compounds and their metabolites are found in natural and wastewater. However, investigation of their toxic effects on aquatic animals has been neglected, especially for metabolites. This work investigated the effects of the main metabolites of carbamazepine, venlafaxine and tramadol. Zebrafish embryos were exposed (0.1-100 µg/L) for 168hpf exposures to each metabolite (carbamazepine-10,11-epoxide, 10,11-dihydrocarbamazepine, O-desmethylvenlafaxine, N-desmethylvenlafaxine, O-desmethyltramadol, N-desmethyltramadol) or the parental compound. A concentration-response relationship was found for the effects of some embryonic malformations. Carbamazepine-10,11-epoxide, O-desmethylvenlafaxine and tramadol elicited the highest malformation rates. All compounds significantly decreased larvae responses on a sensorimotor assay compared to controls. Altered expression was found for most of the 32 tested genes. In particular, abcc1, abcc2, abcg2a, nrf2, pparg and raraa were found to be affected by all three drug groups. For each group, the modelled expression patterns showed differences in expression between parental compounds and metabolites. Potential biomarkers of exposure were identified for the venlafaxine and carbamazepine groups. These results are worrying, indicating that such contamination in aquatic systems may put natural populations at significant risk. Furthermore, metabolites represent a real risk that needs more scrutinising by the scientific community.

In vivo assessment of inflammatory cytokines induced oxidative stress signalling, and troponin I gene dysregulation in cardiac tissue associated with chronic administration of boldenone and tramadol, alone or in combination.

INTRODUCTION: The risk of cardiotoxicity is associated with the use of anabolic-androgenic steroids and analgesics, several deaths were attributed to such medications. OBJECTIVES: This study investigates the effects of boldenone (BOLD) and tramadol (TRAM) alone or in combination on the heart. MATERIAL AND METHODS: Forty adult male rats were divided into four groups. Normal control group, BOLD (5 mg/kg, i.m.) per week, tramadol Hcl (TRAM) (20 mg/kg, i.p.) daily and a combination of BOLD (5 mg/kg) and TRAM (20 mg/kg), respectively for two months. Serum and cardiac tissue were extracted for determination of serum, aspartate aminotransferase (AST), creatine phosphokinase (CPK) and lipid profiles, tissue malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), nitric oxide (NO), tumour necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and histopathological examination. Troponin I gene expression was quantified in cardiac tissue using real-time polymerase chain reaction technique. RESULTS: Groups received BOLD and TRAM alone and in combination showed elevated serum biochemical parameters (AST, CPK) and deviations in lipid profiles, elevation in oxidative and inflammatory parameters (MDA, NO, TNF-α and IL-6), and decrease in GSH and SOD, up-regulated cardiac troponin I as well as distorted cardiac histopathological pictures. CONCLUSION: The current study elucidated the risk of administration of these drugs for sustained periods as well as the marked detrimental effects of using these drugs in combination.

The Behavioral and Neurochemical Changes Induced by Boldenone and/or Tramadol in Adult Male Rats.

Boldenone and tramadol are abused among large sectors of adolescents. Therefore, the behavioral changes concerned with memory and cognitive functions and neurochemical variations were investigated in the cortex of rats treated with boldenone and/or tramadol. Rats were divided into control and rats treated with boldenone, tramadol, or both drugs. At the end of the treatment period, the memory and cognitive functions were evaluated by the Y-maze test (YMT) and elevated plus maze test (EPMT) and the motor activity was determined by the open field test (OFT). The cortex was dissected to carry out the neurochemical analyses. Rats treated with boldenone and/or tramadol showed impaired memory and cognitive functions and reduced motor activity. A significant increase in lipid peroxidation (MDA), nitric oxide (NO), and a significant decrease in reduced glutathione (GSH) were observed in the cortex of rats treated with boldenone and/or tramadol. The levels of acetylcholinesterase (AChE) and monoamine oxidase (MAO) decreased significantly. Western blot data showed a significant decrease in Bcl2 and a significant increase in caspase-3 and inducible nitric oxide synthase (iNOS) in rats treated with boldenone and/or tramadol. These changes were associated with neuronal death as indicated from the histopathological examination.The present findings indicate that boldenone and/or tramadol induced impairment in memory and cognitive functions. These changes could be mediated by the increase in oxidative stress, neuroinflammation, reduced AChE level, and reduced number of survived neurons in the cortex as indicated from the decreased Bcl2 level and the histological examination.

Tramadol-induced apoptosis in auditory hair cells of adult male rats.

Reports have emerged on the sudden opioid-induced auditory hearing loss, and the underlying pathology is not fully understood. The present study aimed to determine the mechanism of action of these drugs in the inner ear. For this purpose, 20 rats were treated with 50 mg/kg tramadol daily for three weeks. Next, the stereological and immunohistochemical alteration of the inner hair cells under chronic exposure to tramadol was evaluated. The results revealed that tramadol induced hair cell degeneration and decreased bipolar neurons of the spiral ganglion and the thickness of stria vascularis. Moreover, immunohistochemistry showed that tramadol caused apoptosis in inner hair cells and bipolar neurons. These findings indicate that tramadol induces apoptosis in auditory hair cells, suggesting that tramadol may cause hearing loss and ototoxicity.

Comparative Study of the Neurotoxic Effects of Pregabalin Versus Tramadol in Rats.

In Egypt, both pregabalin and tramadol misuse increased in the last decade. Although many studies have confirmed the neurotoxic effects of tramadol, those of pregabalin are understudied. The aim of the study is to evaluate the neurotoxic effects of pregabalin compared with tramadol. Thirty male albino rats were included in this experimental study, and they were randomly allocated into three equal groups: group I (normal saline), group II (tramadol misuse), and group III (pregabalin misuse). All rats received the commenced drugs for 1 month. Open field tests were performed on the day of scarification, and after that, cortical samples were taken for immunohistochemical analysis and quantification of dopamine receptors' gene expression. The drug misuse groups showed a significant decrease in weight gain at the end of the study. Open field testing showed the upper hand of controls regarding all of the tested parameters. Tramadol has a more negative impact on the locomotor parameters compared with pregabalin. Both drugs induced relatively low dopamine-1 receptor (D1Rs) expression to dopamine-2 receptors (D2Rs), mimicking the schizophrenia model. Both tramadol and pregabalin were associated with neurotoxic effects in male albino rats. These effects were less noticed with pregabalin. It is suggested that long-term abuse may end in psychosis.

Tramadol and Codeine Stacking/Boosting Dose Exposure Induced Neurotoxic Behaviors, Oxidative Stress, Mitochondrial Dysfunction, and Neurotoxic Genes in Adolescent Mice.

In spite of the increasing epidemic of pharmaceutical opioids (codeine and tramadol) misuse and abuse among the adolescents, little is known about the neurotoxic consequences of the widespread practice of tramadol and codeine abuse involving increasing multiple doses across days, referred to as stacking and boosting. Hence, in this study, we replicated stacking and boosting doses of tramadol, codeine alone, or in combination on spontaneous motor activity and cognitive function in adolescent mice and adduced a plausible mechanism of possible neurotoxicity. Ninety-six adolescent mice were randomly distributed into 4 groups (n = 24 per group) and treated thrice daily for 9 days with vehicle, tramadol (20, 40, or 80 mg/kg), codeine (40, 80, or 160 mg/kg), or their combinations. Exposure of mice to tramadol induced hyperactivity and stereotypic behavior while codeine exposure caused hypoactivity and nootropic effect but tramadol-codeine cocktail led to marked reduction in spontaneous motor activity and cognitive function. In addition, tramadol, codeine, and their cocktail caused marked induction of nitroso-oxidative stress and inhibition of mitochondrial complex I activity in the prefrontal cortex (PFC) and midbrain (MB). Real-time PCR expression profiling of genes encoding neurotoxicity (RT) showed that tramadol exposure upregulate 57 and downregulate 16 neurotoxic genes, codeine upregulate 45 and downregulate 25 neurotoxic genes while tramadol-codeine cocktail upregulate 52 and downregulate 20 neurotoxic genes in the PFC. Findings from this study demonstrate that the exposure of adolescents mice to multiple and increasing doses of tramadol, codeine, or their cocktail lead to spontaneous motor coordination deficits indicative of neurotoxicity through induction of oxidative stress, inhibition of mitochondrial complex I activity and upregulation of neurotoxicity encoding genes in mice.

Exercise training amplifies SIRT1/Nrf2/antioxidant/testosterone pathway after long-time tramadol toxicity in rat testicles; insights into miR-126-3p and miR-181a induced roles.

A long-time consumption of the tramadol (TRA) is shown to negatively affect spermatogenesis development through inducing oxidative stress and suppressing testicular endocrine status. Therefore, by focusing on miRNAs-related roles in the SIRT1/Nrf2/antioxidant/Testosterone-related pathway, the effects of exercise training protocols (ETPs) with different intensities on the TRA-reduced antioxidant and endocrine capacities were investigated. Thus, 36 mature Wistar rats were divided into control and TRA-received groups. Following 60 days, 6 rats from TRA group euthanized (TRA), and the others subdivided into TRA (C.TRA), TRA+low-intensity (TRA+LICT), TRA+moderate-intensity (TA+MICT), and TRA+high-intensity continuous (TRA+HICT) ETP-induced groups (N = 6/group, ETPs were induced for 60 days after stopping TRA consumption). Next, the SIRT1, Nrf2, SOD1, HO-1, miR-126-3p, and miR-181a expression levels were evaluated. The sperm count, testosterone levels, testicular total antioxidant status (TAC), total oxidant status (TOS), superoxide dismutase (SOD) levels, protein carbonyl groups (PCGs), Thiobarbituric acid reactive substances (TBARS), glutathione peroxidase (GPX) and glutathione reductase (GR), oxidative DNA damage were investigated. The TRA group exhibited a significant (p < 0.05) disruption in testicular antioxidant (TAC↓, TOS↑, SOD1↓, SOD enzyme↓, GPX↓, GR↑, TBARS↓, PCGs↑, and HO-1↓) and endocrine (testosterone↓) capacities, a reduction in SIRT1, Nrf2, miR-126-3p, and increment in miR-181a expression levels, a reduction in sperm count and increment in the sperm and testicular oxidative DNA damage. However, The ETPs (mainly LICT) could significantly decrease the TRA-induced molecular and histological alterations 60 days after stopping TRA consumption. In conclusion, ETPs (mainly LICT) through upregulating miR-126-3p and suppressing miR-181a expression levels could promote the SIRT1/Nrf2/antioxidant/Testosterone-related pathway in the testicular tissue.

Combined molecular, structural and memory data unravel the destructive effect of tramadol on hippocampus.

Tramadol is a synthetic analogue of codeine and stimulates neurodegeneration in several parts of the brain that leads to various behavioral impairments. Despite the leading role of hippocampus in learning and memory as well as decreased function of them under influence of tramadol, there are few studies analyzing the effect of tramadol administration on gene expression profiling and structural consequences in hippocampus region. Thus, we sought to determine the effect of tramadol on both PC12 cell line and hippocampal tissue, from gene expression changes to structural alterations. In this respect, we investigated genome-wide mRNA expression using high throughput RNA-seq technology and confirmatory quantitative real-time PCR, accompanied by stereological analysis of hippocampus and behavioral assessment following tramadol exposure. At the cellular level, PC12 cells were exposed to 600 µM tramadol for 48 hrs, followed by the assessments of ROS amount and gene expression levels of neurotoxicity associated with neurodegenerative pathways such as apoptosis and autophagy. Moreover, the structural and functional alteration of the hippocampus under chronic exposure to tramadol was also evaluated. In this regard, rats were treated with tramadol at doses of 50 mg/kg for three consecutive weeks. In vitro data revealed that tramadol provoked ROS production and caused the increase in the expression of autophagic and apoptotic genes in PC12 cells. Furthermore, in-vivo results demonstrated that tramadol not only did induce hippocampal atrophy, but it also triggered microgliosis and microglial activation, causing upregulation of apoptotic and inflammatory markers as well as over-activation of neurodegeneration. Tramadol also interrupted spatial learning and memory function along with long-term potentiation (LTP). Taken all together, our data disclosed the neurotoxic effects of tramadol on both in vitro and in-vivo. Moreover, we proposed a potential correlation between disrupted biochemical cascades and memory deficit under tramadol administration.

Toxicokinetics of U-47700, tramadol, and their main metabolites in pigs following intravenous administration: is a multiple species allometric scaling approach useful for the extrapolation of toxicokinetic parameters to humans?

New synthetic opioids (NSOs) pose a public health concern since their emergence on the illicit drug market and are gaining increasing importance in forensic toxicology. Like many other new psychoactive substances, NSOs are consumed without any preclinical safety data or any knowledge on toxicokinetic (TK) data. Due to ethical reasons, controlled human TK studies cannot be performed for the assessment of these relevant data. As an alternative animal experimental approach, six pigs per drug received a single intravenous dose of 100 µg/kg body weight (BW) of U-47700 or 1000 µg/kg BW of tramadol to evaluate whether this species is suitable to assess the TK of NSOs. The drugs were determined in serum and whole blood using a fully validated method based on solid-phase extraction and LC-MS/MS. The concentration-time profiles and a population (pop) TK analysis revealed that a three-compartment model best described the TK data of both opioids. Central volumes of distribution were 0.94 L/kg for U-47700 and 1.25 L/kg for tramadol and central (metabolic) clearances were estimated at 1.57 L/h/kg and 1.85 L/h/kg for U-47700 and tramadol, respectively. The final popTK model parameters for pigs were upscaled via allometric scaling techniques. In comparison to published human data, concentration-time profiles for tramadol could successfully be predicted with single species allometric scaling. Furthermore, possible profiles for U-47700 in humans were simulated. The findings of this study indicate that unlike a multiple species scaling approach, pigs in conjunction with TK modeling are a suitable tool for the assessment of TK data of NSOs and the prediction of human TK data.

The effects of quercetin on seizure, inflammation parameters and oxidative stress in acute on chronic tramadol intoxication.

BACKGROUND: Tramadol is a widely used synthetic opioid for moderate to severe pain. Some studies have shown that tramadol can increase oxidative stress in different tissues of the body. Quercetin is also a substance with various biological effects, including antioxidant, anti-inflammatory, hepatoprotective, nephroprotective, and cardioprotective activities. The current investigation aimed at determining the effects of quercetin, with or without naloxone, on tramadol intoxication. METHODS: This study was performed on 30 male Wistar rats divided into five groups: Group I) control group: intraperitoneal injections of normal saline 0.9% for 14 days; Group II) tramadol: 25 mg/kg for 14 days, and then a 50 mg/kg acute dose injection on the last day; Group III) acute quercetin (single dose): tramadol injection as with the second group plus 100 mg/kg of quercetin on the last day; Group IV) chronic quercetin: tramadol injection similar to the second group plus quercetin 100 mg/kg for 14 days; Group V) quercetin plus naloxone: tramadol injection similar to the second group plus injection of quercetin 100 mg/kg + intravenous naloxone 2 mg/kg on the last day, followed by a 4 mg/kg/h injection of naloxone for six hours. The rats were monitored for six hours on the last day, relating to the number and severity of seizures. Finally, the samples were prepared for biochemical investigation of the serum level of oxidative stress markers (MDA, SOD, NOx), inflammatory factors (IL-6, TNF-α), biochemical parameters (ALT, AST, creatinine, glucose) and hematological assay. The liver, heart, kidney, cortex, cerebellum, and adrenal tissues were collected to investigate the redox state. RESULTS: None of the treatments had positive effects on the number and severity of seizures. Chronic administration of quercetin led to alteration of some blood parameters, including reduced hemoglobin level and elevated platelet counts. Acute on chronic tramadol administration resulted in a significant rise in AST, where different treatments failed to reduce their levels down to the control group. CONCLUSION: chronic administration of quercetin showed decreased oxidative/nitrosative stress in the liver, kidney, adrenal, and heart tissues. Quercetin plus naloxone decreased oxidative stress in the heart and adrenal tissues, but adverse effects on the brain cortex and hepatic function. Single-dose quercetin reduced cardiac oxidative stress.

Effects of naloxone and diazepam on blood glucose levels in tramadol overdose using generalized estimating equation (GEE) model; (an experimental study).

BACKGROUND: Tramadol is a synthetic opioid and poisoning is increasing around the world day by day. Various treatments are applied for tramadol poisoning. Due to the unknown effects of tramadol poisoning and some of its treatments on blood glucose levels, this study was conducted to investigate the overdose of tramadol and its common treatments (naloxone, diazepam), and their combination on blood glucose levels in male rats. METHODS: This study was conducted in 45 male Wistar rats. The animals were randomly divided into five groups of 9. They received a 75 mg/kg dose of tramadol alone with naloxone, diazepam, and a combination of both of these two drugs. On the last day, animals' tail vein blood glucose levels (BGL) were measured using a glucometer at different times, including before the tramadol injection (baseline) and 1 hour, 3 hours, and 6 hours after wards. The rats were anesthetized and sacrificed 24 h after the last injection. Blood samples were then taken, and the serum obtained was used to verify the fasting glucose concentration. Data were analyzed using SPSS software at a significance level of 0.05 using a one-way analysis of variance (ANOVA) and a generalized estimating equation (GEE). RESULTS: According to the GEE model results, the diazepam-tramadol and naloxone-diazepam-tramadol groups showed blood glucose levels five units higher than the tramadol group (p < 0.05). The diazepam-tramadol group had significantly higher blood glucose levels than the naloxone-tramadol group (p < 0.05). The mean blood glucose levels before the intervention, 3 hours and 6 hours after the injection of tramadol did not differ between the groups, but the blood glucose levels 1 hour after the injection of tramadol in the group of naloxone-tramadol were significantly lower than in the control group (p < 0.05). Blood glucose levels did not differ between the groups 24 h after injection of tramadol. CONCLUSION: The results of the present study showed tramadol overdose does not affect blood glucose levels. The diazepam-tramadol combination and the diazepam-naloxone-tramadol combination caused an increase in blood glucose levels.

Maternotoxicity and fetotoxicity in Rattus norvegicus albinus exposed to tramadol during the late phase of pregnancy.

OBJECTIVES: Tramadol, an atypical opioid, is clinically efficacious in treating moderate to severe pain. The aim of current study was to find out the toxicological effects of tramadol exposure to pregnant rats and fetuses during the late phase of pregnancy. METHODS: Wistar pregnant rats were exposed to 1.25, 2.5, or 5 mg/kg/day tramadol from 14th to 20th day of pregnancy. The same therapy was given to nonpregnant rats for 7 days. The body weight, oral glucose and lipid tolerance tests, and effect on complete blood parameters in both pregnant and nonpregnant rats were determined. On 20th day, maternal placentas were excised and weighed while fetuses were observed for any deformity and growth retardation. Oxidative stress biomarkers were estimated in the liver and kidney tissue homogenates of the pregnant and nonpregnant rats while the whole fetus homogenate was processed for the same. Moreover, histopathology of the liver and kidney of pregnant and nonpregnant rats were carried out. RESULTS: Tramadol administration did not significantly alter the area under curve of the blood glucose and triglyceride levels in both the pregnant and nonpregnant rats. It reduced the live fetuses, placental weights, fetal length, and fetal weights. Tramadol treated pregnant rats showed significantly (p < .05) reduced red blood cells, hematocrit, hemoglobin, and platelets with reference to control group. Similarly, structural abnormalities and malfunctioning of the liver and kidney of pregnant rats were instituted; however, it did not affect the structural integrity of nonpregnant rats. A substantial (p < .001-.0001) altered glutathione and malondialdehyde levels in the fetuses, pregnant, and nonpregnant animals (tissue homogenates) at all dosage levels were indicative of tramadol induced oxidative stress. Furthermore, tramadol exposure resulted in more significant (p < .01-.001) alteration of lipid profile in the pregnant than the nonpregnant animals. CONCLUSION: Acquired results suggested the maternotoxic and fetotoxic effects of tramadol exposure during the late gestation period.

Hepatotoxic effect of tramadol and O-desmethyltramadol in HepG2 cells and potential role of PI3K/AKT/mTOR.

1. The aim of this study was to compare the in vitro cytotoxic effect of tramadol and M1 metabolite in HepG2 cell line, the underlying mechanism, and PI3K/AKT/mTOR as potential target.2. Concentrations representing therapeutic level for tramadol (2 µM) and M1 metabolite (0.5 µM) were used. In addition, other increasing concentrations representing higher toxic levels were used (6, 10 µM for tramadol and 1.5, 2.5 µM for M1 metabolites). Cytotoxicity was assessed at 24, 48 and 72 h.3. Both tramadol and M1 metabolites were able to produce cytotoxicity in a dose and time dependent manner. Insignificant difference was detected between cells exposed to tramadol and M1 metabolite at therapeutic concentrations. Tramadol-induced apoptotic and autophagic cell death while M1 metabolite-induced apoptosis only. For PI3K/AKT/mTOR pathway, the therapeutic concentration of tramadol was only able to increase phosphorylation of AKT while higher toxic concentrations were able to increase phosphorylation of whole pathway; Meanwhile, M1 metabolite was able to increase the phosphorylation of the whole pathway significantly in therapeutic and toxic concentrations.4. In conclusion, both tramadol and M1 are equally cytotoxic. Apoptosis and autophagy both mediate hepatic cell death. PI3K/AKT pathway is involved in apoptosis induction while autophagy is regulated through mTOR independent pathway.

In Vitro and In Vivo Pharmaco-Toxicological Characterization of 1-Cyclohexyl-x-methoxybenzene Derivatives in Mice: Comparison with Tramadol and PCP.

1-cyclohexyl-x-methoxybenzene is a novel psychoactive substance (NPS), first discovered in Europe in 2012 as unknown racemic mixture of its three stereoisomers: ortho, meta and para. Each of these has structural similarities with the analgesic tramadol and the dissociative anesthetic phencyclidine. In light of these structural analogies, and based on the fact that both tramadol and phencyclidine are substances that cause toxic effects in humans, the aim of this study was to investigate the in vitro and in vivo pharmacodynamic profile of these molecules, and to compare them with those caused by tramadol and phencyclidine. In vitro studies demonstrated that tramadol, ortho, meta and para were inactive at mu, kappa and delta opioid receptors. Systemic administration of the three stereoisomers impairs sensorimotor responses, modulates spontaneous motor activity, induces modest analgesia, and alters thermoregulation and cardiorespiratory responses in the mouse in some cases, with a similar profile to that of tramadol and phencyclidine. Naloxone partially prevents only the visual sensorimotor impairments caused by three stereoisomers, without preventing other effects. The present data show that 1-cyclohexyl-x-methoxybenzene derivatives cause pharmaco-toxicological effects by activating both opioid and non-opioid mechanisms and suggest that their use could potentially lead to abuse and bodily harm.

Morphometric, hematological and oxidative stress changes in Clarias gariepinus following sub-chronic exposure to tramadol.

Tramadol is among the most famous analgesic drugs used for the management, treatment and relief of moderate to severe pain conditions. The present study investigated the effects of tramadol on the behavior, mortality, morphometric, hematology and oxidative stress parameters of C. gariepinus juveniles. The 96 h LC50 value of tramadol determined by probit analysis was 88.76 mg/L. Based on this value, fish were exposed to sublethal concentrations of 4.44, 8.88, 17.75 mg/L tramadol and 0.0 mg/L (control) for the period of 15 days and allowed to recover for 5 days. Fish exposed to tramadol showed some abnormal behavioral responses and mortality increased with increase in the exposure duration and concentrations except for the control. There were variations in hepatosomatic index (HSI) and condition factor (CF) in fish exposed to tramadol. Exposure of C. gariepinus to tramadol elicited reduction in the values of white blood cell (WBC), red blood cell (RBC), hemoglobin (Hb), packed cell volume (PCV) and mean corpuscular volume (MCV) while the values of mean corpuscular hemoglobin (MCH) and the mean corpuscular hemoglobin concentration (MCHC) increased. The values of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), reduced glutathione (GSH) and lipid peroxidation (LPO) increased significantly in the exposed fish compared with the control. The values of glutathione peroxidase (GPx) however decreased. The results of the present study demonstrate that tramadol is toxic to fish and its use should be monitored in the aquatic environment.