Binding characteristics of the doxepin E/Z-isomers to the histamine H1 receptor revealed by receptor-bound ligand analysis and molecular dynamics study.

Doxepin is an antihistamine and tricyclic antidepressant that binds to the histamine H1 receptor (H1R) with high affinity. Doxepin is an 85:15 mixture of the E- and Z-isomers. The Z-isomer is well known to be more effective than the E-isomer, whereas based on the crystal structure of the H1R/doxepin complex, the hydroxyl group of Thr1123.37 is close enough to form a hydrogen bond with the oxygen atom of the E-isomer. The detailed binding characteristics and reasons for the differences remain unclear. In this study, we analyzed doxepin isomers bound to the receptor following extraction from a purified H1R protein complexed with doxepin. The ratio of the E- and Z-isomers bound to wild-type (WT) H1R was 55:45, indicating that the Z-isomer was bound to WT H1R with an approximately 5.2-fold higher affinity than the E-isomer. For the T1123.37V mutant, the E/Z ratio was 89:11, indicating that both isomers have similar affinities. Free energy calculations using molecular dynamics (MD) simulations also reproduced the experimental results of the relative binding free energy differences between the isomers for WT and T1123.37V. Furthermore, MD simulations revealed that the hydroxyl group of T1123.37 did not form hydrogen bonds with the E-isomer, but with the adjacent residues in the binding pocket. Analysis of the receptor-bound doxepin and MD simulations suggested that the hydroxyl group of T1123.37 contributes to the formation of a chemical environment in the binding pocket, which is slightly more favorable for the Z-isomer without hydrogen bonding with doxepin.

Pharmacological interventions for antipsychotic-related sialorrhea: a systematic review and network meta-analysis of randomized trials.

Antipsychotic-induced sialorrhea carries a significant burden, but evidence-based treatment guidance is incomplete, warranting network meta-analysis (NMA) of pharmacological interventions for antipsychotic-related sialorrhea. PubMed Central/PsycInfo/Cochrane Central database/Clinicaltrials.gov/WHO-ICTRP and the Chinese Electronic Journal Database (Qikan.cqvip.com) were searched for published/unpublished RCTs of antipsychotic-induced sialorrhea (any definition) in adults, up to 06/12/2023. We assessed global/local inconsistencies, publication bias, risk of bias (RoB2), and confidence in the evidence, conducting subgroup/sensitivity analyses. Co-primary efficacy outcomes were changes in saliva production (standardized mean difference/SMD) and study-defined response (risk ratios/RRs). The acceptability outcome was all-cause discontinuation (RR). Primary nodes were molecules; the mechanism of action (MoA) was secondary. Thirty-four RCTs entered a systematic review, 33 NMA (n = 1958). All interventions were for clozapine-induced sialorrhea in subjects with mental disorders. Regarding individual agents and response, metoclopramide (RR = 3.11, 95% C.I. = 1.39-6.98), cyproheptadine, (RR = 2.76, 95% C.I. = 2.00-3.82), sulpiride (RR = 2.49, 95% C.I. = 1.65-3.77), propantheline (RR = 2.39, 95% C.I. = 1.97-2.90), diphenhydramine (RR = 2.32, 95% C.I. = 1.88-2.86), benzhexol (RR = 2.32, 95% C.I. = 1.59-3.38), doxepin (RR = 2.30, 95% C.I. = 1.85-2.88), amisulpride (RR = 2.23, 95% C.I. = 1.30-3.81), chlorpheniramine (RR = 2.20, 95% C.I. = 1.67-2.89), amitriptyline (RR = 2.09, 95% C.I. = 1.34-3.26), atropine, (RR = 2.03, 95% C.I. = 1.22-3.38), and astemizole, (RR = 1.70, 95% C.I. = 1.28-2.26) outperformed placebo, but not glycopyrrolate or ipratropium. Across secondary nodes (k = 28, n = 1821), antimuscarinics (RR = 2.26, 95% C.I. = 1.91-2.68), benzamides (RR = 2.23, 95% C.I. = 1.75-3.10), TCAs (RR = 2.23, 95% C.I. = 1.83-2.72), and antihistamines (RR = 2.18, 95% C.I. = 1.83-2.59) outperformed placebo. In head-to-head comparisons, astemizole and ipratropium were outperformed by several interventions. All secondary nodes, except benzamides, outperformed the placebo on the continuous efficacy outcome. For nocturnal sialorrhea, neither benzamides nor atropine outperformed the placebo. Active interventions did not differ significantly from placebo regarding constipation or sleepiness/drowsiness. Low-confidence findings prompt caution in the interpretation of the results. Considering primary nodes' co-primary efficacy outcomes and head-to-head comparisons, efficacy for sialorrhea is most consistent for the following agents, decreasing from metoclopramide through cyproheptadine, sulpiride, propantheline, diphenhydramine, benzhexol, doxepin, amisulpride, chlorpheniramine, to amitriptyline, and atropine (the latter not for nocturnal sialorrhea). Shared decision-making with the patient should guide treatment decisions regarding clozapine-related sialorrhea.

Doxepin is more effective than zolpidem in improving executive function in patients with insomnia disorder.

BACKGROUND : Insomnia disorder is associated with an impairment in cognitive performance. Doxepin and zolpidem have been found to be effective in improving sleep. In this study, we aimed to compare the effects of doxepin and zolpidem on sleep structure and executive function in patients with insomnia disorder. METHODS: Patients with primary insomnia were randomly assigned to receive doxepin 6 mg/day orally or zolpidem 5-10 mg/day orally. Polysomnography (PSG) and the Pittsburgh Sleep Quality Index (PSQI) were used at baseline and after the 8-week treatment to compare clinical efficacy in the two groups. Safety was assessed using the Treatment Emergent Symptom Scale (TESS). Executive function was evaluated using the Wisconsin sorting card test (WSCT). RESULTS: Of 120 patients enrolled in the study, 60 participants were assigned to each group. A total of 109 participants (53 in the doxepin group and 56 in the zolpidem group) completed the study. After treatment, the wake after sleep onset (WASO) and total sleep time (TST) values in the doxepin group were 80.3 ± 21.4 min and 378.9 ± 21.9 min, respectively, which were significantly better than those in the zolpidem group (132.9 ± 26.5 min and 333.2 ± 24.2 min, respectively; (P < 0.05)). The sleep onset latency (SOL) value in the zolpidem group (20.3 ± 4.7 min) was significantly better than that in the doxepin group (28.2 ± 5.6 min; P < 0.05). The sleep efficiency (SE) in the doxepin group was 77.8 ± 4.2%, which was significantly better than that in the zolpidem group (68.6 ± 5.0%; P < 0.05). The PSQI score of the doxepin group was 6.1 ± 1.1, which was significantly lower than that in the zolpidem group (7.9 ± 1.9; P < 0.05). The treatment adverse events in the doxepin group was 23.3%, which was significantly higher than that in the zolpidem group (13.3%; P < 0.05). The WSCT showed a significant improvement in persistent errors (PE), random errors (RE), and categories in the two groups after 8-week treatment, and the improvement in RE and the categories was more obvious in the doxepin group (P < 0.05). CONCLUSIONS: Both doxepin and zolpidem were found to be effective in improving sleep quality, but the effects exhibited different patterns. Doxepin improved executive function more effectively than zolpidem in patients with insomnia disorder.

Effectiveness of Antidepressants in Combination with Psychotherapy.

BACKGROUND: Consensus-guidelines for prescribing antidepressants recommend that clinicians should be vigilant to match antidepressants to patient's medical history but provide no specific advice on which antidepressant is best for a given medical history. AIMS OF THE STUDY: For patients with major depression who are in psychotherapy, this study provides an empirically derived guideline for prescribing antidepressant medications that fit patients' medical history. METHODS: This retrospective, observational, cohort study analyzed a large insurance database of 3,678,082 patients. Data was obtained from healthcare providers in the U.S. between January 1, 2001, and December 31, 2018. These patients had 10,221,145 episodes of antidepressant treatments. This study reports the remission rates for the 14 most commonly prescribed single antidepressants (amitriptyline, bupropion, citalopram, desvenlafaxine, doxepin, duloxetine, escitalopram, fluoxetine, mirtazapine, nortriptyline, paroxetine, sertraline, trazodone, and venlafaxine) and a category named "Other" (other antidepressants/combination of antidepressants). The study used robust LASSO regressions to identify factors that affected remission rate and clinicians' selection of antidepressants. The selection bias in observational data was removed through stratification. We organized the data into 16,770 subgroups, of at least 100 cases, using the combination of the largest factors that affected remission and selection bias. This paper reports on 2,467 subgroups of patients who had received psychotherapy. RESULTS: We found large, and statistically significant, differences in remission rates within subgroups of patients. Remission rates for sertraline ranged from 4.5% to 77.86%, for fluoxetine from 2.86% to 77.78%, for venlafaxine from 5.07% to 76.44%, for bupropion from 0.5% to 64.63%, for desvenlafaxine from 1.59% to 75%, for duloxetine from 3.77% to 75%, for paroxetine from 6.48% to 68.79%, for escitalopram from 1.85% to 65%, and for citalopram from 4.67% to 76.23%. Clearly these medications are ideal for patients in some subgroups but not others. If patients are matched to the subgroups, clinicians can prescribe the medication that works best in the subgroup. Some medications (amitriptyline, doxepin, nortriptyline, and trazodone) always had remission rates below 11% and therefore were not suitable as single antidepressant therapy for any of the subgroups. DISCUSSIONS: This study provides an opportunity for clinicians to identify an optimal antidepressant for their patients, before they engage in repeated trials of antidepressants. IMPLICATIONS FOR HEALTH CARE PROVISION AND USE: To facilitate the matching of patients to the most effective antidepressants, this study provides access to a free, non-commercial, decision aid at http://MeAgainMeds.com. IMPLICATIONS FOR HEALTH POLICIES:  Policymakers should evaluate how study findings can be made available through fragmented electronic health records at point-of-care. Alternatively, policymakers can put in place an AI system that recommends antidepressants to patients online, at home, and encourages them to bring the recommendation to their clinicians at their next visit. IMPLICATIONS FOR FURTHER RESEARCH:  Future research could investigate (i) the effectiveness of our recommendations in changing clinical practice, (ii) increasing remission of depression symptoms, and (iii) reducing cost of care. These studies need to be prospective but pragmatic. It is unlikely random clinical trials can address the large number of factors that affect remission.

Intranasal delivery of doxepin: enhancing brain targeting efficiency utilizing nanostructured lipid carriers for a biopharmaceutics drug disposition classification system class-I drug.

Doxepin, a Class-I Biopharmaceutics Drug Disposition Classification System (BDDCS) drug, exhibits poor bioavailability due to extensive first-pass metabolism. This research focuses on enhancing the delivery of doxepin by formulating nanostructured lipid carriers (NLCs) through the utilization of the Box-Behnken Design methodology. These optimized NLCs are intended for intranasal administration, with the ultimate goal of improving nose-to-brain drug delivery. NLCs were formulated using a high-speed homogenization technique. The optimized batch had a small particle size (75.80 ± 5.48 nm, PDI = 0.286), high entrapment efficiency (94.10 ± 0.16%), and sustained ex vivo release (82.25 ± 4.61% at 24 h). Characterization studies confirmed the conversion of doxepin from a crystalline to an amorphous state with uniform distribution in the lipid matrix. In vivo pharmacokinetic studies in rats showed significantly higher doxepin concentration in the brain tissue (Cmax = 16.77 µg/g, tmax = 30 min) after intranasal administration compared to intravenous administration (Cmax = 2.53 µg/g, tmax = 6 h). High-drug targeting efficiency (DTE = 284.3%) and direct transport percentage (DTP = 64.8%) suggested direct penetration of NLCs in the brain via olfactory and trigeminal pathways. In conclusion, the study highlights the potential of NLCs to improve the bioavailability of doxepin through nose-to-brain delivery and thereby potentially enable the treatment of neurological disorders.

Unlocking the secrets of doxepin hydrochloride's crystal structure: Insights from high-quality powder diffraction analysis.

Doxepin hydrochloride, a versatile pharmaceutical compound, has been the subject of extensive research aimed at elucidating its crystal structure and solid-state characteristics. In this manuscript, we explore the significance of high-quality powder diffraction data in unveiling the intricate details of doxepin hydrochloride's crystal lattice. By examining the refined atom coordinates, density functional theory (DFT) optimization, and intermolecular interactions, we gain valuable insights into its structural conformation. This knowledge highlights the importance of precise crystallographic data in advancing our understanding of complex compounds and their pharmaceutical applications.

Comparative effects of pharmacological interventions for the acute and long-term management of insomnia disorder in adults: a systematic review and network meta-analysis.

BACKGROUND: Behavioural, cognitive, and pharmacological interventions can all be effective for insomnia. However, because of inadequate resources, medications are more frequently used worldwide. We aimed to estimate the comparative effectiveness of pharmacological treatments for the acute and long-term treatment of adults with insomnia disorder. METHODS: In this systematic review and network meta-analysis, we searched the Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, Embase, PsycINFO, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, and websites of regulatory agencies from database inception to Nov 25, 2021, to identify published and unpublished randomised controlled trials. We included studies comparing pharmacological treatments or placebo as monotherapy for the treatment of adults (≥18 year) with insomnia disorder. We assessed the certainty of evidence using the confidence in network meta-analysis (CINeMA) framework. Primary outcomes were efficacy (ie, quality of sleep measured by any self-rated scale), treatment discontinuation for any reason and due to side-effects specifically, and safety (ie, number of patients with at least one adverse event) both for acute and long-term treatment. We estimated summary standardised mean differences (SMDs) and odds ratios (ORs) using pairwise and network meta-analysis with random effects. This study is registered with Open Science Framework, https://doi.org/10.17605/OSF.IO/PU4QJ. FINDINGS: We included 170 trials (36 interventions and 47 950 participants) in the systematic review and 154 double-blind, randomised controlled trials (30 interventions and 44 089 participants) were eligible for the network meta-analysis. In terms of acute treatment, benzodiazepines, doxylamine, eszopiclone, lemborexant, seltorexant, zolpidem, and zopiclone were more efficacious than placebo (SMD range: 0·36-0·83 [CINeMA estimates of certainty: high to moderate]). Benzodiazepines, eszopiclone, zolpidem, and zopiclone were more efficacious than melatonin, ramelteon, and zaleplon (SMD 0·27-0·71 [moderate to very low]). Intermediate-acting benzodiazepines, long-acting benzodiazepines, and eszopiclone had fewer discontinuations due to any cause than ramelteon (OR 0·72 [95% CI 0·52-0·99; moderate], 0·70 [0·51-0·95; moderate] and 0·71 [0·52-0·98; moderate], respectively). Zopiclone and zolpidem caused more dropouts due to adverse events than did placebo (zopiclone: OR 2·00 [95% CI 1·28-3·13; very low]; zolpidem: 1·79 [1·25-2·50; moderate]); and zopiclone caused more dropouts than did eszopiclone (OR 1·82 [95% CI 1·01-3·33; low]), daridorexant (3·45 [1·41-8·33; low), and suvorexant (3·13 [1·47-6·67; low]). For the number of individuals with side-effects at study endpoint, benzodiazepines, eszopiclone, zolpidem, and zopiclone were worse than placebo, doxepin, seltorexant, and zaleplon (OR range 1·27-2·78 [high to very low]). For long-term treatment, eszopiclone and lemborexant were more effective than placebo (eszopiclone: SMD 0·63 [95% CI 0·36-0·90; very low]; lemborexant: 0·41 [0·04-0·78; very low]) and eszopiclone was more effective than ramelteon (0.63 [0·16-1·10; very low]) and zolpidem (0·60 [0·00-1·20; very low]). Compared with ramelteon, eszopiclone and zolpidem had a lower rate of all-cause discontinuations (eszopiclone: OR 0·43 [95% CI 0·20-0·93; very low]; zolpidem: 0·43 [0·19-0·95; very low]); however, zolpidem was associated with a higher number of dropouts due to side-effects than placebo (OR 2·00 [95% CI 1·11-3·70; very low]). INTERPRETATION: Overall, eszopiclone and lemborexant had a favorable profile, but eszopiclone might cause substantial adverse events and safety data on lemborexant were inconclusive. Doxepin, seltorexant, and zaleplon were well tolerated, but data on efficacy and other important outcomes were scarce and do not allow firm conclusions. Many licensed drugs (including benzodiazepines, daridorexant, suvorexant, and trazodone) can be effective in the acute treatment of insomnia but are associated with poor tolerability, or information about long-term effects is not available. Melatonin, ramelteon, and non-licensed drugs did not show overall material benefits. These results should serve evidence-based clinical practice. FUNDING: UK National Institute for Health Research Oxford Health Biomedical Research Centre.

Determination of doxepin hydrochloride in spiked human plasma and capsule after derivatization with eosin Y using resonance Rayleigh scattering, second-order scattering and frequency doubling scattering methods.

Doxepin hydrochloride (DOX) is a tricyclic antidepressant drug. Three sensitive spectrofluorimetric methods, namely resonance Rayleigh scattering (RRS), frequency doubling scattering (FDS) and second-order scattering (SOS), were developed and validated for their estimation of doxepin in spiked human plasma and formulation using liquid-liquid extraction method through the formation of an ion pair complex with eosin Y at a pH of 4.5. Various factors affecting fluorescence intensity were optimized, and the reaction kinetics was determined using the Arrhenius equation method. Different scattering methods such as RRS, FDS and SOS were developed at maximum scattering wavelengths λex /λem = 567/567 nm for RRS, 720/360 nm for SOS and 260/520 nm for FDS, respectively. The methods exhibited high sensitivities, and the detection limits for DOX were found to be 0.82, 1.20 and 1.03 ng/ml for RRS, FDS and SOS methods, respectively. The FDS method exhibited the highest sensitivity. The methods were validated using the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines and applied to determine DOX in capsule and spiked human plasma samples.

A novel chitosan-based doxepin nano-formulation for chemotherapy-induced oral mucositis: a randomized, double-blinded, placebo-controlled clinical trial.

OBJECTIVES: Considering the prevalence of oral mucositis, we aimed to use the analgesic effects of doxepin with chitosan's antimicrobial and bio-adhesive nature to fabricate a nano-formulation for treating chemotherapy-induced oral mucositis. MATERIALS AND METHODS: Nanogel was fabricated via ionic gelation and characterized. Sixty patients were randomly divided and received four different treatments for 14 days: diphenhydramine + aluminum-magnesium mouthwash (control), doxepin mouthwash (DOX MW), chitosan nanogel (CN), and doxepin/chitosan nanogel (CN + DOX). Lesions were assessed with four indices, National Cancer Institute (NCI), World Health Organization (WHO), World Conference on Clinical and Research in Nursing (WCCNR) and visual analog scale (VAS) before and 3, 7, and 14 days after interventions. Kruskal-Wallis test was used for pairwise comparison. RESULTS: CN had semisolid consistency, uniform spherical shape, an average size of 47.93 ± 21.69 nm, and a zeta potential of + 1.02 ± 0.16 mV. CN + DOX reduced WHO, WCCNR, and VAS scores significantly more than the control three days after the intervention. Seven days after the intervention, CN + DOX reduced NCI and WCCNR considerably more than the control; it reduced WCCNR significantly more than CN. Fourteen days after the intervention, CN + DOX decreased NCI markedly more than the control. CONCLUSION: Chitosan-based doxepin nano-formulation might be a promising alternative for routine treatments of oral mucositis.

Topical delivery of doxepin using liposome containing cream: An emerging approach in enhancing skin retention.

Conventional formulation of topical doxepin has similar antihistaminic effects as oral doxepin; however, its efficacy is limited due to poor localized effects on the skin. This study was designed to compare the ex vivo permeation and retention of two topical doxepin formulations; liposomal cream and plain cream. Doxepin-containing liposomes were prepared with the thin-film hydration method and assessed for size, size distribution, morphology, entrapment efficiency (EE%) and stability Using rat skin specimens in a Franz diffusion cell. Doxepin concentration in skin and receptor fluid was quantified by a validated HPLC method. The optimized liposomal formulation represented a uniform shape with narrow size distribution and an average diameter of 208.7±5.6nm. EE% of doxepin was 79±1.3 and the liposomes were stable at least for six weeks at 4°C. Ex vivo studies showed that while a significantly higher amount of doxepin has passed through the skin and entered the receptor compartment from conventional dosage form (47.06±2.5µg/cm2vs 11.20±0.6µg/cm2 for liposomal formulation), liposomal doxepin favoured accumulation in dermis and epidermis. These results suggest that the liposomal doxepin cream is an effective and easy-to-use formulation and may improve the cutaneous retention of doxepin, thus decreasing its systemic side effects.

Host-guest complexation between cucurbit[7]uril and doxepin induced supramolecular assembly.

The supramolecular complexation of doxepin (DOX) with cucurbit[7]uril (CB7) was investigated in aqueous solution. The results indicated the formation of a host-guest complex, as verified by complexation-induced chemical shifts in the NMR experiments and supported by quantum-chemical calculations, in which the alkylammonium tail of DOX was found to be encapsulated inside the CB7 cavity, while the tricyclic moiety remained exposed to bulk water. Isothermal titration calorimetry and dye-displacement experiments provided a moderate binding affinity (104 M-1). Interestingly, the partial encapsulation of DOX by the CB7 macrocycle led to the development of a supramolecular assembly at a low millimolar concentration, as verified by NMR and dynamic light scattering (DLS) measurements, which showed homogeneous size distributions with an average diameter of 1700 nm.

Effect of Ions and Sequence Variants on the Antagonist Binding Properties of the Histamine H1 Receptor.

The histamine H1 receptor (H1R) is a G protein-coupled receptor (GPCR) and represents a main target in the treatment of allergic reactions as well as inflammatory reactions and depressions. Although the overall effect of antagonists on H1 function has been extensively investigated, rather little is known about the potential modulatory effect of ions or sequence variants on antagonist binding. We investigated the dynamics of a phosphate ion present in the crystal structure and of a sodium ion, for which we determined the position in the allosteric pocket by metadynamics simulations. Both types of ions exhibit significant dynamics within their binding site; however, some key contacts remain stable over the simulation time, which might be exploited to develop more potent drugs targeting these sites. The dynamics of the ions is almost unaffected by the presence or absence of doxepin, as also reflected in their small effect (less than 1 kcal·mol-1) on doxepin binding affinity. We also examined the effect of four H1R sequence variants observed in the human population on doxepin binding. These variants cause a reduction in doxepin affinity of up to 2.5 kcal·mol-1, indicating that personalized medical treatments that take into account individual mutation patterns could increase precision in the dosage of GPCR-targeting drugs.

Development and validation of a simultaneous analytical method for non-steroidal therapeutic compounds in cosmetics using liquid chromatography-tandem mass spectrometry.

Atopic dermatitis is a typical chronic inflammatory skin disease that affects all age groups and requires basic skin care for treatment. Anti-inflammatory and antiallergy steroids are the most frequently used treatments but they are limited due to their side effects caused by a weakening of the immune system. Many consumers focus on performance as a criterion for selecting cosmetics. However, steroids have been illegally used to improve the performance of cosmetics, and consumers have been adversely affected by the corresponding side effects. In this paper, we propose a simple and rapid method using liquid chromatography-tandem mass spectrometry to simultaneously analyze ten non-permitted atopic therapeutic compounds in cosmetic products: chlorpheniramine maleate, ketotifen fumarate, doxepin hydrochloride, azelastine hydrochloride, bufexamac, clotrimazole, tranilast, fusidic acid, tacrolimus, and pimecrolimus. Additionally, the major characteristic fragment ions for tacrolimus, pimecrolimus, and clotrimazole were identified by time-of-flight mass spectrometry. The specificity, linearity, limit of detection, limit of quantification, recovery, precision, accuracy, and stability of the proposed method were validated. The limit of detection and quantification were in the ranges of 5.05-203.30 pg/mL and 15.15-609.90 pg/mL, respectively. The proposed analysis method could help improve the safety management of cosmetics.

Protective effects of doxepin cream on radiation dermatitis in breast cancer: A single arm double-blind randomized clinical trial.

AIMS: Breast cancer is the most frequently occurring cancer in women. Lumpectomy followed by radiotherapy is suggested to be as effective as a total mastectomy. Radiation-induced dermatitis often occurs as a result of breast radiotherapy. Recent studies suggest that doxepin has promising anti-inflammatory properties. This study was undertaken to evaluate the effects of doxepin therapy on radiation dermatitis. METHODS: A double-blind randomized clinical trial was launched from 2016 to 2017, with a total of 48 patients who had undergone breast-conserving surgery and received postoperative radiation therapy. Radiotherapy was applied 5 days per week for 5 weeks. Adverse dermatological effects were evaluated by a physician at the beginning of the fifth week of radiotherapy and the patients were then randomly assigned (1:1 ratio) to receive either doxepin (5%) or placebo cream for 7 days. RESULTS: There were no significant differences in the dermatitis grade between doxepin and placebo groups at baseline (P > .5). The occurrence of acute dermatitis (grade 2 or higher) was significantly lower with the use of doxepin than with placebo (P ≤ .0001, Zα = 1.96 at 95% confidence interval). CONCLUSION: Doxepin cream prevents dermatitis grade 2 or higher during post-operative breast irradiation. Doxepin cream is easy to use, affordable and prevents pain and irritation.

Nortriptyline serum concentration as a predictor for cardiac risk in amitriptyline-treated patients.

PURPOSE: Tricyclic antidepressants have been shown to affect electrocardiogram (ECG) parameters, but there is limited evidence in relation to the serum concentrations. Therefore, we aimed to evaluate a prediction of cardiac risk in amitriptyline- and doxepin-treated patients by serum concentrations. PATIENTS AND METHODS: The association between serum concentrations of amitriptyline (n = 100) and doxepin (n = 71) and ECG parameters was retrospectively examined using linear regression analysis. Mann-Whitney U tests were applied to evaluate differences in QTc intervals in patients with serum concentrations above and below the upper limit of the therapeutic reference range, as well as the alert level of each target drug. RESULTS: The sum serum concentration of amitriptyline and the nortriptyline serum concentration were significantly associated with an increased PQ interval (p = 0.020, p = 0.007), as well as with increased QTcB (p = 0.012, p < 0.001) and QTcF intervals (p = 0.025, p < 0.001). The nortriptyline concentration was significantly associated with the QRS interval (p = 0.003). In patients with active moiety concentrations above the alert level (300 ng/ml) and nortriptyline concentrations above the reference range (170 ng/ml), the QTcB interval was significantly prolonged (p = 0.032, p = 0.007). No significant association with any ECG parameter was detected for doxepin serum concentrations. CONCLUSION: The effect of amitriptyline on ECG parameters may be explained by nortriptyline alone. Accordingly, with increasing nortriptyline concentrations, the potential risk for an atrioventricular block, a bundle branch block, and prolongation of QTc interval may increase significantly.

Anti-inflammatory effects of doxepin hydrochloride against LPS-induced C6-glioma cell inflammatory reaction by PI3K-mediated Akt signaling.

Recent studies have shown that tricyclic antidepressants (TCAs) may have anti-inflammatory and anticonvulsant effects in addition to its antidepressant effects. So far, the nonantidepressant effects of TCAs and their molecular pharmacological mechanisms remain completely unclear. Chronic inflammation in the brain parenchyma may be related to the pathogenesis and progression of various neurodegenerative diseases. As a common antidepressant and anti-insomnia drug, doxepin also may be a potential anti-inflammatory and anticonvulsant drug, so the study on the anti-inflammatory protective effect of doxepin and its molecular mechanism has become a very important issue in pharmacology and clinical medicine. Further elucidating the anti-inflammatory and neuroprotective effects of doxepin and its molecular mechanism may provide the important theoretical and clinical basis for the prevention and treatment of neurodegenerative disease. This study was designed to understand the glio-protective mechanism of doxepin against the inflammatory damage induced by lipopolysaccharide (LPS) exposure in C6-glioma cells. We found the treatment of C6-glioma cells with LPS results in deleterious effects, including the augmentation of inflammatory cytokine levels (tumor necrosis factor-α, interleukin-1ß), and suppresses the Akt phosphorylation. Furthermore, our outcomes demonstrated that doxepin was able to suppress these effects induced by LPS, through activation of the phosphatidylinositol-3-kinase-mediated protein kinase B (Akt) pathway. To sum up, these results highlight the potential role of doxepin against neuroinflammatory-related disease in the brain.

Comparison of gabapentin and doxepin in the management of uremic pruritus: A randomized crossover clinical trial.

Gabapentin and doxepin are well-known treatments of uremic pruritus in hemodialysis patients but no head-to-head studies were conducted to date. The aim of this trial is to compare the efficacy and the tolerability of gabapentin and doxepin in the treatment of uremic pruritus in hemodialysis patients. A single-blind crossover randomized trial was conducted that included hemodialysis patients with uremic pruritus. Patients were randomized to receive 10 mg doxepin daily or 100 mg gabapentin for 4 weeks and the two groups were treated conversely for another 4 weeks after a 4-week washout period. Eighty-five patients were screened for eligibility. Thirty-one met the inclusion criteria and four were excluded. Sixteen patients agreed and signed the consent and two withdrew from the study. VAS scores at baseline were 6.71 and 6.14, and dropped to 0.57 and 2.35 at week 4 in the gabapentin and doxepin groups, respectively. Mean scores of the 5-Domain Itch Scale (5-D) at baseline were 14.71 and 14.64, and dropped to 5.78 and 7.57 at week 4 in the gabapentin and doxepin groups, respectively. Mean scores of the Dermatology Life Quality Index (DLQI) at baseline were 9.6429 and 8.7857, and dropped to 0.71 and 3.35 at week 4 in the gabapentin and doxepin groups, respectively. Reductions in Visual Analog Scale (VAS), 5-D and DLQI were statistically significant (P < .05). No serious side effects were recorded. Limitations of this study include single-blind design, small number of included cases and lack of placebo control. Gabapentin was more effective than doxepin in decreasing uremic pruritus severity and improving quality of life of these patients.

Polyoxomolybdate368 /polyaniline nanocomposite as a novel fiber for solid-phase microextraction of antidepressant drugs in biological samples.

A novel solid-phase microextraction fiber was synthesized by coating a stainless steel wire with polyoxomolybdate368 /polyaniline as a sorbent aimed at extraction of amitriptyline, nortriptyline, and doxepin as antidepressant drugs from urine and blood samples. The polyoxomolybdate368 /polyaniline composite coating was applied using electropolymerization process under constant potential. This composition leads to enhanced extraction efficiency of the fiber. Scanning electron microscopy images show that huge three-dimensional structures of polyoxomolybdate368 in composite induced more non-smooth and porous fiber. In order to optimize of the extraction process, a series of variables including concentration of the composite materials, coating thickness, pH, extraction time, salt addition, and stirring rate was investigated and optimum conditions were determined. Analysis of surface morphology and chemical composition was performed. High-performance liquid chromatography was used for separation and evaluation of mentioned antidepressant drugs from the matrixes. The experiments indicated a detection limits of <0.2 ng/L and a linear dynamic range of 0.3-100 ng/L (R2  > 0.994). The relative recovery values were found to be in the range of 92-98%. It was concluded that the purposed fiber is highly efficient in analyzing traces of antidepressant drugs in urine and blood.

High-throughput protein precipitation method with 96-well plate for determination of doxepin and nordoxepin in human plasma using LC-MS/MS.

The aim of this study was to establish a high-throughput and sensitive LC-MS/MS method for the determination of doxepin and its major active metabolite nordoxepin in human plasma. It has been designed for bioequivalence study for formulations containing 25 mg of doxepin. Doxepin and nordoxepin were extracted from human plasma samples by protein precipitation with acetonitrile by using protein precipitation 96-well plates. The analyte was separated using a Phenomenex Kinetex Biphenyl column (100 × 2.1 mm, 2.6 µm) using isocratic elution with a mobile phase of 20 mM ammonium formate (30%) and acetonitrile:methanol 3:7 v:v (70%) at a flow rate of 0.5 mL/min and an injection volume of 10 µL. The detection was performed using a triple quadrupole mass spectrometer by multiple reaction monitoring mode to monitor the precursor-to-product ion transitions of m/z 280.4 → 107.0 and 283.4 → 235.0 for doxepin and doxepin-D3, respectively, and 266.3 → 106.9 and 269.3 → 235.0 for nordoxepin and nordoxepin-D3, respectively, in positive electrospray ionization mode. The total run time was 3.5 min. The method was validated over a concentration range of 50-10,000 pg/mL using a Triple Quad 4500 MS System (Sciex) for both analytes. The developed and validated method can be successfully used to study the bioequivalence/pharmacokinetics of doxepin and nordoxepin.

[The interesting anti-H1 effects in maintenance insomnia: A reflection on the comparative advantages of doxylamine and doxepin]. / Les effets anti-H1 intéressants dans les insomnies de maintien : réflexion sur les intérêts comparés de la doxylamine et de la doxépine.

Doxylamine (Donormyl®, Lidene®, Generics) is commonly proposed by pharmacists as a sleeping pill which does not require a prescription. In France, today it is only prescribed for occasional insomnia in adults. In light of knowledge about the role of the histamine H1 inverse agonist drugs in the treatment of insomnia, and specifically the low dose doxepin (3 mg and 6 mg) marketed in the US and Canada (Silenor®), we suggest that the use of doxylamine may be appropriate for treating insomnia in the last third of the night. Better information to the pharmacist on the prescription of this anti-H1 hypnotic would be beneficial to the patient.