Inhibitory Actions of Antidepressants, Hypnotics, and Anxiolytics on Recombinant Human Acetylcholinesterase Activity.

Alzheimer's disease (AD) is accompanied by behavioral and psychological symptoms of dementia (BPSD), which is often alleviated by treatment with psychotropic drugs, such as antidepressants, hypnotics, and anxiolytics. If these drugs also inhibit acetylcholinesterase (AChE) activity, they may contribute to the suppression of AD progression by increasing brain acetylcholine concentrations. We tested the potential inhibitory effects of 31 antidepressants, 21 hypnotics, and 12 anxiolytics on recombinant human AChE (rhAChE) activity. At a concentration of 10-4 M, 22 antidepressants, 19 hypnotics, and 11 anxiolytics inhibited rhAChE activity by <20%, whereas nine antidepressants (clomipramine, amoxapine, setiptiline, nefazodone, paroxetine, sertraline, citalopram, escitalopram, and mirtazapine), two hypnotics (triazolam and brotizolam), and one anxiolytic (buspirone) inhibited rhAChE activity by ≥20%. Brotizolam (≥10-6 M) exhibited stronger inhibition of rhAChE activity than the other drugs, with its pIC50 value being 4.57 ± 0.02. The pIC50 values of the other drugs were <4, and they showed inhibitory activities toward rhAChE at the following concentrations: ≥3 × 10-6 M (sertraline and buspirone), ≥10-5 M (amoxapine, nefazodone, paroxetine, citalopram, escitalopram, mirtazapine, and triazolam), and ≥3 × 10-5 M (clomipramine and setiptiline). Among these drugs, only nefazodone inhibited rhAChE activity within the blood concentration range achievable at clinical doses. Therefore, nefazodone may not only improve the depressive symptoms of BPSD through its antidepressant actions but also slow the progression of cognitive symptoms of AD through its AChE inhibitory actions.

Successful Treatment of Amoxapine-Induced Intractable Seizures With Intravenous Lipid Emulsion.

BACKGROUND: Amoxapine is a second-generation tricyclic antidepressant with a greater seizure risk than other antidepressants. If administered in large amounts, amoxapine can cause severe toxicity and death. Therefore, it is necessary to terminate seizures immediately if amoxapine toxicity occurs. However, intractable seizures often occur in these patients. We describe a case of intractable seizures caused by amoxapine poisoning, in which intravenous lipid emulsion (ILE) was used successfully. CASE REPORT: A 44-year-old woman with a history of depression ingested 3.0 g of amoxapine during a suicide attempt. Although she was initially treated with intravenous diazepam, her seizures persisted. Levetiracetam and phenobarbital were then administered, but seizures persisted. Hence, ILE was injected for over 1 min. At 2 min after ILE administration, the patient's status seizures ceased. Recurrence of seizures was observed 30 min after ILE, and the seizures disappeared after re-administration of ILE. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: ILE may be effective in amoxapine intoxication. Emergency physicians may consider ILE as an adjunctive therapy for amoxapine poisoning with a high mortality rate. ILE should be implemented carefully with monitoring of total dosage and adverse events.

Elucidation of Degradation Behavior of Tricyclic Antidepressant Amoxapine in Artificial Gastric Juice.

The degradation behavior of eight tricyclic antidepressants (TCAs; amitriptyline, amoxapine (AMX), imipramine, clomipramine, desipramine, doxepin, dothiepin, and nortriptyline) in artificial gastric juice was investigated to estimate their pharmacokinetics in the stomach. As a result, among the eight TCAs, only AMX was degraded in artificial gastric juice. The degradation was a pseudo first-order reaction; activation energy (Ea) was 88.70 kJ/mol and activation entropy (ΔS) was -80.73 J/K·mol. On the other hand, the recovery experiment revealed that the degradation product did not revert to AMX and accordingly, this reaction was considered to be irreversible. In the AMX degradation experiment, peaks considered to be degradation products A (I) and B (II) were detected at retention times of around 3 min and 30 min in LC/UV measurements, respectively. Structural analysis revealed that compound (I) was [2-(2-aminophenoxy)-5-chlorophenyl]-piperazin-1-yl-methanone, a new compound, and compound (II) was 2-chlorodibenzo[b,f][1,4]oxazepin-11(10H)-one. As for the degradation behavior, it was estimated that AMX was degraded into (II) via (I), i.e., (II) was the final product. The results are expected to be useful in clinical chemistry and forensic science, including the estimation of drugs to be used at the time of judicial dissection and suspected drug addiction.

Combating Multidrug-Resistant Pathogens with Host-Directed Nonantibiotic Therapeutics.

Earlier, we reported that three Food and Drug Administration-approved drugs, trifluoperazine (TFP; an antipsychotic), amoxapine (AXPN; an antidepressant), and doxapram (DXP; a breathing stimulant), identified from an in vitro murine macrophage cytotoxicity screen, provided mice with 40 to 60% protection against pneumonic plague when administered at the time of infection for 1 to 3 days. In the present study, the therapeutic potential of these drugs against pneumonic plague in mice was further evaluated when they were administered at up to 48 h postinfection. While the efficacy of TFP was somewhat diminished as treatment was delayed to 24 h, the protection of mice with AXPN and DXP increased as treatment was progressively delayed to 24 h. At 48 h postinfection, these drugs provided the animals with significant protection (up to 100%) against challenge with the agent of pneumonic or bubonic plague when they were administered in combination with levofloxacin. Likewise, when they were used in combination with vancomycin, all three drugs provided mice with 80 to 100% protection from fatal oral Clostridium difficile infection when they were administered at 24 h postinfection. Furthermore, AXPN provided 40 to 60% protection against respiratory infection with Klebsiella pneumoniae when it was administered at the time of infection or at 24 h postinfection. Using the same in vitro cytotoxicity assay, we identified an additional 76/780 nonantibiotic drugs effective against K. pneumoniae For Acinetobacter baumannii, 121 nonantibiotic drugs were identified to inhibit bacterium-induced cytotoxicity in murine macrophages. Of these 121 drugs, 13 inhibited the macrophage cytotoxicity induced by two additional multiple-antibiotic-resistant strains. Six of these drugs decreased the intracellular survival of all three A. baumannii strains in macrophages. These results provided further evidence of the broad applicability and utilization of drug repurposing screening to identify new therapeutics to combat multidrug-resistant pathogens of public health concern.

Randomized Crossover Trial of Amoxapine Versus Vitamin B12 for Retrograde Ejaculation.

OBJECTIVE: To compare the efficacy and safety of amoxapine and vitamin B12 for treating retrograde ejaculation (RE). MATERIALS AND METHODS: Between May 2009 and November 2012, this open-label, randomized, crossover study enrolled 26 men suffering with RE at Department of Reproductive Medicine, Omori Hospital. Patients were randomly allocated into two groups (n=13 each). The amoxapine-B12 group received amoxapine (50 mg daily for 4 weeks, orally) followed (after a 1-week washout period) by vitamin B12 (500 µg three-times daily for 4 weeks). The B12-amoxapine group received the opposite regimen. All pa-tients masturbated to ejaculation at least twice during each treatment period. The primary outcome was antegrade ejaculation of semen, as reported by the patient, on more than one occasion during either treatment period (defined as treatment success). Any adverse events were noted. Success rates were compared between treatments using Fisher's exact test. RESULTS: One patient (B12-amoxapine group) withdrew for personal reasons (breakdown of marital relations); all other patients completed the study. Overall success rate was 88% (22/25). Success rate was higher for amoxapine than for vitamin B12 (80%, 20/25 vs 16%, 4/25; P<0.0001). 18 patients were responsive to amoxapine but not to vitamin B12, 2 patients were responsive to vitamin B12 but not amoxapine, 2 patients were responsive to both drugs, and 3 patients had no response to either drug. One patient (4%) reported sleepiness and 2 (8%) reported constipation while receiving amoxapine. No adverse events were reported during vitamin B12 treatment. CONCLUSIONS: Amoxapine may be an effective, safe and well-tolerated therapy for RE.

NEW METHODOLOGY FOR DEVELOPMENT OF ORODISPERSIBLE TABLETS USING HIGH-SHEAR GRANULATION PROCESS.

Development of orodispersible delivery system of high mechanical properties and low disintegration time is a big challenge. The aim of the current work was to assess and optimize the high shear granulation process as a new methodology for development of orodispersible tablets of high quality attributes using design of experiment approach. A two factor, three levels (32), full factorial design was carried out to investigate the main and interaction effects of independent variables, water amount (XI) and granulation time (X2) on the characteristics of granules and final product, tablet. The produced granules were analyzed for their granule size, density and flowability. Furthermore, the produced tablets were tested for: weight variation, breaking force/ crushing strength, friability, disintegration time and drug dissolution. Regression analysis results of multiple linear models showed a high correlation between the adjusted R-squared and predicted R-squared for all granules and tablets characteristics, the difference is less than 0.2. All dependent responses of granules and tablets were found to be impacted significantly (p < 0.05) by the two independent variables. However, water amount demonstrated the most dominant effect for all granules and tablet characteristics as shown by higher its coefficient estimate for all selected responses. Numerical optimization using desirability function was performed to optimize the variables under study to provide orodispersible system within the USP limit with respect of mechanical properties and disintegration time. It was found that the higher desirability (0.915) could be attained at the low level pf water (180 g) and short granulation time (1.65 min). Eventually, this study provides the formulator with helpful information in selecting the proper level of water and granulation time to provide an orodispersible system of high crushing strength and very low disintegration time, when high shear granulation methodology was used as a method of manufacture.

New Role for FDA-Approved Drugs in Combating Antibiotic-Resistant Bacteria.

Antibiotic resistance in medically relevant bacterial pathogens, coupled with a paucity of novel antimicrobial discoveries, represents a pressing global crisis. Traditional drug discovery is an inefficient and costly process; however, systematic screening of Food and Drug Administration (FDA)-approved therapeutics for other indications in humans offers a rapid alternative approach. In this study, we screened a library of 780 FDA-approved drugs to identify molecules that rendered RAW 264.7 murine macrophages resistant to cytotoxicity induced by the highly virulent Yersinia pestis CO92 strain. Of these compounds, we identified 94 not classified as antibiotics as being effective at preventing Y. pestis-induced cytotoxicity. A total of 17 prioritized drugs, based on efficacy in in vitro screens, were chosen for further evaluation in a murine model of pneumonic plague to delineate if in vitro efficacy could be translated in vivo Three drugs, doxapram (DXP), amoxapine (AXPN), and trifluoperazine (TFP), increased animal survivability despite not exhibiting any direct bacteriostatic or bactericidal effect on Y. pestis and having no modulating effect on crucial Y. pestis virulence factors. These findings suggested that DXP, AXPN, and TFP may modulate host cell pathways necessary for disease pathogenesis. Finally, to further assess the broad applicability of drugs identified from in vitro screens, the therapeutic potential of TFP, the most efficacious drug in vivo, was evaluated in murine models of Salmonella enterica serovar Typhimurium and Clostridium difficile infections. In both models, TFP treatment resulted in increased survivability of infected animals. Taken together, these results demonstrate the broad applicability and potential use of nonantibiotic FDA-approved drugs to combat respiratory and gastrointestinal bacterial pathogens.

Development and validation of a sensitive spectrofluorimetric method for the determination of amoxapine in human plasma and urine.

A selective and sensitive spectrofluorimetric method was developed and validated for the determination of amoxapine in human plasma and urine. The developed method is based on labeling with 5-dimethylaminonaphthalene-1-sulfonyl chloride (dansyl chloride) and monitoring at 397 nm (excitation)/514 nm (emission). The method was validated for linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, recovery and robustness. The calibration curves were linear over a concentration range of 250-2500 and 50-1250 ng/mL for plasma and urine, respectively. The LOD values were calculated to be 13.31 and 13.17 ng/mL for plasma and urine, respectively. The proposed method was applied to study of amoxapine in human plasma and urine.

FDA-Approved Amoxapine Effectively Promotes Macrophage Control of Mycobacteria by Inducing Autophagy.

Antibiotic resistance poses a significant hurdle in combating global public health crises, prompting the development of novel therapeutics. Strategies to enhance the intracellular killing of mycobacteria by targeting host defense mechanisms offer numerous beneficial effects, which include reducing cytotoxicity caused by current lengthy anti-tubercular treatment regimens and slowing or circumventing the development of multidrug-resistant strains. The intracellular pathogen Mycobacterium tuberculosis infects macrophages and exploits host machinery to survive and multiply. Using a cell-based screen of FDA-approved drugs, we identified an antidepressant, Amoxapine, capable of inhibiting macrophage cytotoxicity during mycobacterial infection. Notably, this reduced cytotoxicity was related to the enhanced intracellular killing of Mycobacterium bovis BCG and M. tuberculosis within human and murine macrophages. Interestingly, we discovered that postinfection treatment with Amoxapine inhibited mTOR (mammalian target of rapamycin) activation, resulting in the induction of autophagy without affecting autophagic flux in macrophages. Also, inhibition of autophagy by chemical inhibitor 3-MA or knockdown of an essential component of the autophagic pathway, ATG16L1, significantly diminished Amoxapine's intracellular killing effects against mycobacteria in the host cells. Finally, we demonstrated that Amoxapine treatment enhanced host defense against M. tuberculosis in mice. In conclusion, our study identified Amoxapine as a novel host-directed drug that enhances the intracellular killing of mycobacteria by induction of autophagy, with concomitant protection of macrophages against death. IMPORTANCE The emergence and spread of multidrug-resistant (MDR) and extensive drug-resistant (XDR) TB urges the development of new therapeutics. One promising approach to combat drug resistance is targeting host factors necessary for the bacteria to survive or replicate while simultaneously minimizing the dosage of traditional agents. Moreover, repurposing FDA-approved drugs presents an attractive avenue for reducing the cost and time associated with new drug development. Using a cell-based screen of FDA-approved host-directed therapies (HDTs), we showed that Amoxapine inhibits macrophage cytotoxicity during mycobacterial infection and enhances the intracellular killing of mycobacteria within macrophages by activating the autophagy pathway, both in vitro and in vivo. These findings confirm targeted autophagy as an effective strategy for developing new HDT against mycobacteria.

Preparation and characterization of amoxapine- and naringin-loaded solid lipid nanoparticles: drug-release and molecular-docking studies.

Aim: Amoxapine (AMX) has been reported to be metabolized by CYP3A4 and CYP2D6. Naringin (NG) has been reported to inhibit CYP enzymes. Therefore, the current work was designed to develop AMX solid lipid nanoparticles (AMX-SLNs) and NG-SLNs for better therapeutic performance. Materials & methods: AMX-SLNs and NG-SLNs were prepared and characterized. AMX and NG interactions with CYP450s were studied with molecular docking to rationalize the effectiveness of the combination. Results: AMX-SLNs and NG-SLNs showed nanometric size with a sustained in vitro drug-release profile. NG showed a higher predicted binding affinity for CYP3A4 and CYP2D6, suggesting the potential for inhibition. Conclusion: The developed formulations were thoroughly characterized along with molecular docking data indicating promising AMX and NG combinations that may show good therapeutic activity.

Over-Expression of GUSB Leads to Primary Resistance of Anti-PD1 Therapy in Hepatocellular Carcinoma.

Immunotherapy treatments, particularly immune checkpoint blockade, can result in benefits in clinical settings. But many pre-clinical and clinical studies have shown that resistance to anti-PD1 therapy frequently occurs, leading to tumor recurrence and treatment failure, including in patients with hepatocellular carcinoma (HCC). In this study, 10 patients with HCC were remedied with anti-PD1, and pre-treatment biopsy samples were sequenced for 289 nanostring panel RNA to compare responsive and non-responsive tumors to identify possible pretreatment biomarkers or targets of anti-PD1 therapeutic responses. Fortunately, the expression of ß-Glucuronidase (GUSB) in the non-responding tumors was found to be remarkably higher than that in responding tumors. Results of the cell counting kit 8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), transwell, wound healing test, and flow cytometry showed that GUSB facilitated proliferation, invasion, as well as migration of human HCC cells and downregulated PD-L1 expression by promoting miR-513a-5p. Additionally, as a GUSB inhibitor, amoxapine can reduce the progression of human HCC cells, and was an effective treatment for HCC and improved the sensitivity of anti-PD1 therapy. In summary, this study reveals that increased GUSB downregulates PD-L1 expression by promoting miR-513a-5p, leading to primary resistance to anti-PD1 treatment in HCC, and amoxapine enhances the sensitivity of anti-PD1 therapy by inhibiting GUSB, providing a new strategy and method for improving the efficacy of anti-PD1 therapy and bringing new prospects for therapy of HCC.

Amoxapine inhibits delayed outward rectifier K(+) currents in cerebellar granule cells via dopamine receptor and protein kinase A activation.

BACKGROUND: Although tricyclic antidepressants amoxapine is proposed to target 5-HT and D2 receptors, very few studies have addressed the effect of amoxapine on molecular and cellular mechanisms via receptor pathways. In this study, we test the effect of amoxapine on rat cerebellar granule neurons (CGNs) to address this possibility. METHODS: CGNs cell culture, whole-cell current recording using a patch-clamp technique, western blot and non-radioactive detection analysis of phosphorylated protein kinase A (PKA) were used. RESULTS: Amoxapine inhibits delayed rectifier potassium (I(K)) current in a dose-dependent manner and modulates inactivation properties in CGNs. Those effects were not eliminated by preincubation with 5-HT or 5-HT receptor antagonists, but abolished by dopamine and D1/D5 receptor antagonists. Application of GTPγ-S and inhibitor of the Gs signalling cascade abolished the amoxapine-induced effect on I(K). The application of forskolin or dibutyryl-cAMP mimicked the inhibitory effect of amoxapine on I(K). Western blotting for phosphorylated PKA revealed that amoxapine significantly increased the intracellular levels of phosphorylated PKA, a marker of PKA activation. CONCLUSION: Amoxapine inhibits I(K) currents in rat CGNs via cAMP/PKA-dependent pathways, as in mouse cortical neurons we reported earlier, but that involves D1-like receptors instead of 5-HT receptors.

Antidepressant Screening Demonstrated Non-Monotonic Responses to Amitriptyline, Amoxapine and Sertraline in Locomotor Activity Assay in Larval Zebrafish.

Antidepressants are well-known drugs to treat depression and major depressive disorder for humans. However, the misuse and abuse of antidepressants keep increasing with several side effects reported. The aim of this study was to assess the potential adverse effects of 18 antidepressants by monitoring zebrafish larval locomotor activity performance based on the total distance traveled, burst movement count, and total rotation count at four dark-light intercalated phases. In general, zebrafish larvae displayed sedative effects after antidepressant exposure by showing a significant reduction in all of the locomotor activity-related endpoints. However, three antidepressants i.e., amitriptyline, amoxapine, and sertraline were able to trigger a significantly high locomotor activity in zebrafish larvae during the light cycle. These differences might be due to the pharmacologic differences among the antidepressants. In addition, since each antidepressant possesses a different dosage range from the other, overdoses of these antidepressants might also be the causes of these differences. Furthermore, based on these results, a further study was conducted to observe the effect of these three antidepressants in lower concentrations. From the results, biphasic effects in terms of zebrafish larval locomotor activity were demonstrated by these drugs. Even though further studies are still required to validate the mechanism, these findings indicate that these antidepressants might share a common mechanism responsible for their effects on zebrafish larval locomotor activity although there were some differences in potency of these effects.

Amoxapine inhibits the delayed rectifier outward K+ current in mouse cortical neurons via cAMP/protein kinase A pathways.

Ion channels are known to be modulated by antidepressant drugs, but the molecular mechanisms are not known. We have shown that the antidepressant drug amoxapine suppresses rectifier outward K(+) (I(K)) currents in mouse cortical neurons. At a concentration of 10 to 500 muM, amoxapine reversibly inhibited I(K) in a dose-dependent manner and modulated both steady-state activation and inactivation properties. The application of forskolin or dibutyryl cAMP mimicked the inhibitory effect of amoxapine on I(K) and abolished further inhibition by amoxapine. N-[2-(p-Bromocinnamylamino)ethyl]-5-iso-quinolinesulphonamide (H-89), a protein kinase A (PKA) inhibitor, augmented I(K) amplitudes and completely eliminated amoxapine inhibition of I(K). Amoxapine was also found to significantly increase intracellular cAMP levels. The effects of amoxapine on I(K) were abolished by preincubation with 5-hydroxytryptamine (5-HT) and the antagonists of 5-HT(2) receptor. Moreover, intracellular application of guanosine 5'-[gammathio]-triphosphate increased I(K) amplitudes and prevented amoxapine-induced inhibition. The selective Kv2.1 subunit blocker Jingzhaotoxin-III reduced I(K) amplitudes by 30% and also significantly abolished the inhibitory effect of amoxapine. Together these results suggest that amoxapine inhibits I(K) in mouse cortical neurons by cAMP/PKA-dependent pathway associated with the 5-HT receptor, and suggest that the Kv2.1 alpha-subunit may be the target for this inhibition.

Determination of amoxapine and nortriptyline in blood plasma and serum by salt-assisted liquid-liquid microextraction and high-performance liquid chromatography.

A new, selective and sensitive method has been developed for the determination of tricyclic antidepressant drugs, amoxapine and nortriptyline, in human blood plasma and serum, involving their reaction with allyl isothiocyanate and extraction of thiourea derivatives with water-miscible organic solvent acetonitrile. The phase separation was effected by addition of ammonium sulphate, a process called salt-assisted liquid-liquid microextraction. The extract was analyzed by HPLC with UV detection at 254 nm. The method has been optimized for derivatization reaction time and temperature, solvent for extraction, and salt for solvent phase separation. Under the optimal conditions, a linear calibration graph was obtained between the amount of drug and the peak area of thiourea derivatives in the range of 0.002-20 mg/L drugs. The correlation coefficient and limit of detection values for amoxapine and nortriptyline in serum/plasma samples were in the range of 0.9953-0.9999 and 0.46-0.58 µg/L, respectively. The recovery in spiking experiments ranged, respectively, 75-88% (RSD 3.4-7.2%) and 79-97% (RSD 3.7-7.9%) for the two drugs.

Effect of Antidepressants on Psychotic Symptoms in Parkinson Disease: A Review of Case Reports and Case Series.

OBJECTIVES: The treatment of Parkinson disease (PD) psychosis remains a challenge. Only a few treatments eliciting significant relief of psychotic symptoms have passed the test of randomized controlled trials. METHODS: Here, we conducted a review of the literature on the effect of antidepressants on PD psychosis. Because there is no randomized controlled trial that assessed the antipsychotic effects of antidepressants in PD, only case reports, case series, and open-label trials were available to review. Because of the scarce literature, statistical analysis could not be performed. RESULTS: The following antidepressants alleviated hallucinations in PD: amoxapine, citalopram, clomipramine, escitalopram, mianserin, mirtazapine, and venlafaxine. The antidepressants were generally well tolerated, with the exception of amoxapine, which exacerbated parkinsonism. CONCLUSIONS: Whereas the conclusions that can be drawn on the efficacy of antidepressants at reducing PD psychosis are limited because of the poor quality of the reported studies, it is encouraging to notice that there are positive anecdotal reports. Further studies are needed to confirm the potential of these drugs and also to determine if a subtype of patients or of psychotic features may be more likely to be improved by antidepressants.

New Host-Directed Therapeutics for the Treatment of Clostridioides difficile Infection.

Frequent and excessive use of antibiotics primes patients to Clostridioides difficile infection (CDI), which leads to fatal pseudomembranous colitis, with limited treatment options. In earlier reports, we used a drug repurposing strategy and identified amoxapine (an antidepressant), doxapram (a breathing stimulant), and trifluoperazine (an antipsychotic), which provided significant protection to mice against lethal infections with several pathogens, including C. difficile However, the mechanisms of action of these drugs were not known. Here, we provide evidence that all three drugs offered protection against experimental CDI by reducing bacterial burden and toxin levels, although the drugs were neither bacteriostatic nor bactericidal in nature and had minimal impact on the composition of the microbiota. Drug-mediated protection was dependent on the presence of the microbiota, implicating its role in evoking host defenses that promoted protective immunity. By utilizing transcriptome sequencing (RNA-seq), we identified that each drug increased expression of several innate immune response-related genes, including those involved in the recruitment of neutrophils, the production of interleukin 33 (IL-33), and the IL-22 signaling pathway. The RNA-seq data on selected genes were confirmed by quantitative real-time PCR (qRT-PCR) and protein assays. Focusing on amoxapine, which had the best anti-CDI outcome, we demonstrated that neutralization of IL-33 or depletion of neutrophils resulted in loss of drug efficacy. Overall, our lead drugs promote disease alleviation and survival in the murine model through activation of IL-33 and by clearing the pathogen through host defense mechanisms that critically include an early influx of neutrophils.IMPORTANCEClostridioides difficile is a spore-forming anaerobic bacterium and the leading cause of antibiotic-associated colitis. With few therapeutic options and high rates of disease recurrence, the need to develop new treatment options is urgent. Prior studies utilizing a repurposing approach identified three nonantibiotic Food and Drug Administration-approved drugs, amoxapine, doxapram, and trifluoperazine, with efficacy against a broad range of human pathogens; however, the protective mechanisms remained unknown. Here, we identified mechanisms leading to drug efficacy in a murine model of lethal C. difficile infection (CDI), advancing our understanding of the role of these drugs in infectious disease pathogenesis that center on host immune responses to C. difficile Overall, these studies highlight the crucial involvement of innate immune responses, as well as the importance of immunomodulation as a potential therapeutic option to combat CDI.

Amoxapine-associated acute respiratory distress.

A 37-year-old woman was admitted to our hospital because of acute respiratory distress. Two weeks previously, amoxapine (75 mg/day) had been administered for the first time. Ten days later she developed a high fever, severe hypoxaemia and pulmonary infiltrates on chest CT, including patchy areas of ground-glass opacity, thickening of the interlobular septae and bronchial walls and pleural effusions. BAL showed a predominance of neutrophils, lymphocytes and erythrocytes but not eosinophils. Amoxapine was stopped, resulting in complete resolution of the pulmonary infiltrates. When the patient was re-exposed to amoxapine (52.5 mg total dose), high fever, reduced SaO(2) and pulmonary infiltrates reappeared. We concluded that acute respiratory distress may be associated with amoxapine treatment.

Determination of tricyclic antidepressants in human plasma using pipette tip solid-phase extraction and gas chromatography-mass spectrometry.

A method for the simultaneous extraction of four tricyclic antidepressants from human plasma samples using pipette tip SPE with MonoTip C(18) tips is presented. Human plasma (0.1 mL) containing four tricyclic antidepressants (amitriptyline, amoxapine, imipramine, and trimipramine) and an internal standard (IS), protriptyline, was mixed with 0.4 mL of distilled water and 100 microL 1 M NaOH solution. After centrifugation of the mixture, the supernatant was extracted to the C(18) phase of the tip by 20 repeated aspirating/dispensing cycles using a manual micropipettor. The analytes retained in the tip were eluted with methanol by five repeated aspirating/dispensing cycles. Without evaporation and reconstitution, the eluate was directly injected into a gas chromatograph injector and detected by a mass spectrometer with SIM in the positive-ion electron impact mode. Recovery of the four antidepressants and IS spiked into human plasma was 80.2-92.1%. The regression equations for the four antidepressants showed excellent linearity in the range of 0.2-40 ng/0.1 mL. LODs and LOQs for the four drugs were 0.05-0.2 ng/0.1 mL and 0.2-0.5 ng/0.1 mL, respectively. Intra- and interday CVs for the four drugs in plasma were no greater than 9.5%.

An autopsy case of poisoning with ethanol and psychotropic drugs.

A case of fatal poisoning involving ethanol with psychotropic drugs is presented. Quantitative toxicological analysis showed that the concentrations of ethanol, amoxapine and phenobarbital in the femoral blood were 2.86 mg/ml, 0.41 microg/ml and 6.80 microg/ml, respectively. We concluded that the cause of death was due to the combination use of ethanol, amoxapine and phenobarbital.