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and the Chinese Electronic Journal Database (Qikan.cqvip.com) were searched for published/unpublished RCTs of antipsychotic-induced sialorrhea (any definition) in adults, up to 06/12/2023.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.

Marijuana and endoscopy: the effects of marijuana on sedation.

BACKGROUND AND AIMS: Marijuana usage has increased significantly as it has become more readily available and legal, either recreationally or medicinally, in many states. It has been postulated that marijuana usage increases the amount of sedation required for procedures. However, there are minimal data defining this relationship. We aimed to establish the relationship between marijuana usage and the amount of sedation used during endoscopy. METHODS: This was a single-institution prospective study of patients undergoing outpatient endoscopy (both monitored anesthesia care [MAC] and moderate sedation) at the Oklahoma City Veterans Affairs Medical Center. Marijuana usage was assessed by a voluntary de-identified pre-endoscopy survey. Information regarding sedation used, endoscopy outcomes, demographics, comorbidities, medical history, and medications used was extracted from the medical record. A univariate and stratified analysis of alcohol usage was performed. A P value of <.05 was considered to be significant. RESULTS: A total of 976 patients were analyzed; 21.5% of them endorsed marijuana usage (210/976). Marijuana users were found to be younger (P = .0002), leaner (P < .0001), and less likely to have diabetes (P = .002), obstructive sleep apnea (P = .0002), and hypertension (P = .04). They were also more likely to smoke (P < .0001) and vape (P < .0001). Marijuana usage was associated with a higher requirement of sedation (fentanyl [P = .003], midazolam [P = .05], propofol [P = .02]) and higher use of adjunct sedation (diphenhydramine in moderate sedation [P = .0003]). Further multivariate analyses were performed to control for possible confounders. Marijuana usage was still deemed to be an independent predictor for high propofol use among MAC cases (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.00-3.12). Likewise, marijuana usage was found to be an independent predictor for high midazolam use (OR, 1.57; 95% CI, 1.02-2.42) and high fentanyl use (OR, 1.54; 95% CI, 0.98-2.38), but failed to reach statistical significance in the fentanyl group. CONCLUSIONS: Marijuana use is associated with a significantly higher amount of sedation along with a significantly higher usage of other adjunct sedatives. A patient's marijuana history should be considered when determining the methods of sedation to be used for endoscopy.

Green micellar liquid chromatographic method for simultaneous determination of antihistaminic drugs tripelennamine hydrochloride and diphenhydramine in pharmaceutical gel.

A new green micellar liquid chromatographic method has been developed and validated for the simultaneous determination of diphenhydramine (DPH) and tripelennamine hydrochloride (TRP) using a micellar mobile phase consisting of 1 mM Tween 20 in phosphate buffer pH 4:isopropanol (85:15, %v/v). The method was linear in the range of 4-150 and 5-120 µg/mL for TRP and DPH, respectively. The method was successfully applied for the simultaneous determination of DPH and TRP in a laboratory-prepared gel containing all possible excipients with mean percent recoveries ± standard deviation of 100.346 ± 1.265 and 100.754 ± 1.117 for TRP and DPH, respectively. The method was validated according to the International Conference on Harmonization guidelines. The method is confirmed to have excellent greenness.

Precipitated opioid withdrawal in a patient started on olanzapine/samidorphan.

BACKGROUND: Olanzapine/Samidorphan (Lybalvi®) is a novel oral agent for the treatment of schizophrenia and bipolar I disorder. It was designed to reduce weight gain associated with olanzapine. Samidorphan is an analog of naltrexone, initially intended to treat substance use disorders by antagonizing mu, delta, and kappa opioid receptors. CASE REPORT: We present the case of a 36-year-old who took their first dose of olanzapine/samidorphan shortly before calling for emergency services. The patient took diphenhydramine and an epinephrine autoinjector for what they thought was an allergic reaction but continued to have symptoms. EMS reported involuntary muscle movements thought to be due to dystonia from olanzapine. In the ED, they experienced generalized muscle spasms lasting for several seconds and diaphoresis. Initially, the staff treated for a presumed dystonic reaction to olanzapine and administered diphenhydramine 25 mg IV, diazepam 2 mg IV, midazolam 5 mg IV, and benztropine 1 mg IV without improvement. It was later determined that the patient took 16 mg of buprenorphine SL daily. With this information, precipitated opioid withdrawal was felt to be the likely cause of symptoms. The patient received 16 mg of buprenorphine for an initial Clinical Opiate Withdrawal Scale (COWS) score of 11 with repeat COWS of 6. Why should an emergency physician be aware of this? Initiating olanzapine/samidorphan in the setting of chronic opioid therapy may result in precipitated opioid withdrawal. Additional SL buprenorphine may be a reasonable treatment modality.

INDIVIDUAL ARTICLE: Efficacy of a Prebiotic Skincare Regimen on Improving Mild Atopic Dermatitis and Severe Xerosis in Diverse Ethnically Patients.

Atopic Dermatitis (AD) is a chronic relapsing inflammatory skin disease associated with a significant patient burden on quality-of-life. Given skin barrier including skin microbiome changes are linked to AD pathogenesis, prebiotic emollients are shown to improve disease symptoms and maintain skin barrier integrity, normalizing skin microbiota. In this study, we evaluated the efficacy and safety of a prebiotic skincare routine in improving AD and xerosis, and ultimately quality-of-life in ethnically diverse patients. A total of 140 subjects from different racial/ethnic backgrounds, aged 3-80 years old with skin phototypes I-VI, and presenting with mild-AD or severe xerosis completed study. Expert grading, instrumentation, self-assessment questionnaires, plus clinical imaging demonstrated that a prebiotic cleanser and moisturizer routine significantly reduced skin conditions severity, strengthened skin barrier properties in both lesional and normal skin, and improved patients' quality-of-life while providing itch relief as soon as 4 weeks. The results of this research indicate that a prebiotic cleanser and moisturizer regimen offers benefits for diverse patient’s daily skincare routine by effectively managing AD and xerosis severity and symptoms, normalizing skin microbiota, plus preserving skin barrier integrity to prevent long-term sequelae. J Drugs Dermatol. 2024;23:3(Suppl 2):s12-22.

Initial updosing phase of oral immunotherapy improves quality of life and psychological burden in parents of children with food allergy.

Background: Oral immunotherapy (OIT) can impose psychological burdens on patients and their parents due to the necessary preparations and repeated adverse reactions. Objective: To investigate changes in quality of life (QoL) and psychological burden in parents of children receiving OIT for food allergy (FA). Methods: Children aged 3-13 years with FA were enrolled. Parents were asked to fill out the Korean versions of the Food Allergy Quality of Life-Parental Burden (FAQL-PB), the Korean versions of the Food Allergy Quality of Life-Parental Form (K-FAQLQ-PF), the Korean versions of the Beck Anxiety Inventory (K-BAI), and the Korean version of the Patient Health Questionnaire-9 (PHQ-9) for depression before OIT (T1), after 2 months of updosing (T2), and after the end of the updosing phase (T3). Results: A total of 111 parents were enrolled. The total FAQL-PB scores were decreased at T2 and T3 compared with those at T1 (all p < 0.001). Greater improvement in the total FAQL-PB score at T2 was noted in parents with a higher parental burden (FAQL-PB score ≥ 74 points) at baseline than in those with a lower parental burden (p = 0.001). Among the K-FAQLQ-PF domains, "food anxiety" scores were decreased at T2 and T3 compared with those at T1 (p = 0.049 and p = 0.030, respectively), whereas there was no change in "social and dietary limitation" and "emotional impact" scores between T1 and T2 and between T1 and T3. However, no differences were observed in K-BAI and PHQ-9 scores between T1 and T2 and between T1 and T3. Conclusion: Our results suggest that OIT improves parental burden and QoL in parents of children with FA.

Green micellar factorial design optimized first derivative synchronous spectrofluorimetric method for tripelennamine and diphenhydramine determination in pharmaceutical gel.

A green micellar synchronous spectrofluorimetric method was developed and validated for simultaneous determination of tripelennamine hydrochloride and diphenhydramine in bulk and combined pharmaceutical formulation. Synchronous fluorescence of tripelennamine hydrochloride and diphenhydramine was determined using Δλ = 60 nm. The first derivative of synchronous fluorescence was computed to resolve overlap in the synchronous fluorescence spectra. Tripelennamine hydrochloride was quantified at 375 nm, whereas diphenhydramine was quantified at 293 nm; each is the zero-crossing point of the other. As diphenhydramine exhibited weak native fluorescence, micelle enhancement upon incorporation of sodium dodecyl sulfate was considered. Two-level full factorial design was carried out to optimize experimental parameters. Optimum conditions involved using SDS (2% w/v) along with Teorell and Stenhagen buffer (pH 9). The method was found to be linear over the range 0.2-4.5 and 0.2-5 µg/mL for tripelennamine and diphenhydramine, respectively, with limits of detection 0.211 and 0.159 µg/mL. The method was successfully applied for simultaneous determination of tripelennamine hydrochloride and diphenhydramine in laboratory-prepared gel containing all possible excipients with mean percent recoveries ±SD 100.59 ± 0.79 and 98.99 ± 0.98 for tripelennamine hydrochloride and diphenhydramine, respectively. The proposed method was proved to be eco-friendly using different greenness assessment tools.

Diphenhydramine-involved Fatal and Nonfatal Drug Overdoses in Tennessee, 2019-2022.

BACKGROUND: Diphenhydramine (DPH), known as the brand name Benadryl, is an over-the-counter medication associated with accidental ingestion leading to nonfatal overdoses. Additionally, DPH has been used in tandem with illicit substances leading to fatal drug overdoses. OBJECTIVE: In response to DPH being seized with illicit drugs as an adulterant, as well as its growing intentional misuse, we sought to explore its recent involvement in fatal and nonfatal drug overdoses in the state of Tennessee. METHODS: We conducted a statewide cross-sectional study to determine the characteristics of DPH-involved fatal and nonfatal overdoses in Tennessee during 2019-2022 using data from the State Unintentional Drug Overdose Reporting System, the Electronic Surveillance System for the Early Notification of Community-based Epidemics, and the National Forensic Laboratory Information System Public Data Query System. Frequencies were generated to compare demographic characteristics, circumstances, and toxicology between fatal and nonfatal DPH-involved overdoses. RESULTS: We identified 143 suspected nonfatal DPH and 409 fatal DPH-involved overdoses in Tennessee from 2019 to 2022. Nonfatal overdoses remained consistent while fatal overdoses peaked in 2021. Most nonfatal overdoses were under 18 (63.4%), while most fatal overdoses were between 18 and 64 years of age (95.7%). For fatal overdoses, fentanyl was the most prevalent substance on toxicology followed by prescription opioids. CONCLUSION: Nonfatal overdoses remained consistent while fatal overdoses peaked in 2021 in Tennessee. Use of DPH among other illicit substances lends to evidence suggesting its use as an adulterant. Monitoring of DPH-involved fatal and nonfatal overdoses is critical to inform harm reduction initiatives.

Diphenhydramine and Migraine Treatment Failure in Pediatric Patients Receiving Prochlorperazine.

OBJECTIVES: The objectives are to determine whether diphenhydramine coadministered with prochlorperazine versus prochlorperazine only is associated with a difference in the risk of migraine treatment failure, as measured by the need for additional therapy, hospitalization rates, and 72-hour return rates, and to compare extrapyramidal adverse effects between groups. METHODS: Retrospective cohort of patients aged 7 to 18 years treated in the emergency department for migraines using prochlorperazine with or without diphenhydramine between 2013 and 2019. Patients were included if they had International Classification of Diseases, Ninth or Tenth Revision, codes for migraine or unspecified headache and were treated with prochlorperazine as part of their initial migraine therapy. Data collected included demographics, medications administered, pain scores, neuroimaging, disposition, return visits, and documentation of extrapyramidal adverse effects. Multivariable logistic regression was used to estimate the association between diphenhydramine coadministration and each of the outcomes. RESULTS: A total of 1683 patients were included. Overall, 13% required additional therapy with a 16.7% admission rate and a 72-hour return rate of 5.3%. There was no association between initial treatment with diphenhydramine and the odds of additional therapy (adjusted odds ratio [aOR], 0.74 [95% confidence interval {CI}, 0.53-1.03]), admission rates (aOR, 1.22 [95% CI, 0.89-1.67]), or return visit rates (aOR, 0.91 [95% CI, 0.55-1.51]). Extrapyramidal adverse effects occurred in 2.4% of patients in the prochlorperazine group and 0% in the prochlorperazine with diphenhydramine group. CONCLUSIONS: There was no association between diphenhydramine coadministration and the need for additional therapy, 72-hour return visit rates or admission rates. Extrapyramidal effects did not occur in patients treated with diphenhydramine.

Comparing the Risk of Infusion-Related Reactions and Tolerability in Patients Given Cetirizine or Diphenhydramine Prior to Ocrelizumab Infusion (PRECEPT).

Background: Ocrelizumab is an effective medication for multiple sclerosis. However, infusion-related reactions (IRRs) are a concern for patients and may lead to discontinuation of ocrelizumab. To minimize IRRs, pre-medications are administered. However, from our experience, these medications, especially diphenhydramine, can cause marked drowsiness. The primary objective of this study was to evaluate whether cetirizine is non-inferior to diphenhydramine in limiting the proportion and severity of reactions from ocrelizumab infusions. Methods: Twenty participants were serially randomized in a 1:1 ratio to receive 10 mg of cetirizine or 25 mg of diphenhydramine orally prior to their first three ocrelizumab infusions. Results: The rate of IRRs in this study was similar across both treatment groups with no increase in the risk of severity, and no grade 3 IRRs. Further, patients receiving cetirizine experienced a reduction in fatigue. While there was not a significant difference in global satisfaction, this score increased over time in the cetirizine arm while it remained unchanged in the diphenhydramine arm. Conclusions: Overall, our results suggest that cetirizine does not increase the risk of infusion-related reactions compared to diphenhydramine.

Safety and technical success of diphenhydramine as an alternative local anaesthetic agent for radiology procedures.

AIM: To evaluate retrospectively the safety and technical success of subcutaneous diphenhydramine as an alternative local anaesthetic for radiology procedures. MATERIALS AND METHODS: Between January 2000 and April 2021, 84 image-guided procedures were performed in 81 adult patients (mean age 61 years, 86% female) using 1% injectable diphenhydramine as a local anaesthetic. Indications were history of severe allergy to "-caine" local anaesthetics in 76 (90%) patients and recent administration of bupivacaine liposomal injectable suspension in eight (10%) patients. Twelve of the 84 (14%) procedures were performed with concomitant moderate sedation. Patient characteristics, procedural techniques, and clinical outcomes were reviewed. Early and delayed (30-day) complications were classified as either related to local diphenhydramine injection or to the procedure itself. Procedure-related complications were gradated using the Clavien-Dindo system. RESULTS: Percutaneous biopsy was the most frequently performed procedure (57/84, 67%). Fifty-nine (70%) of the 84 procedures were ultrasound guided. The most common procedural site was the breast (34/84, 40%). All procedures were technically successful. There were two minor injection-related complications related to post-procedural pain. A single minor procedure-related complication involved a patient requiring hospital admission for post-renal biopsy related haematuria. CONCLUSION: Injectable diphenhydramine appears to be a safe and effective local anaesthetic alternative in patients with "-caine" class contraindications undergoing radiology procedures. A future prospective trial would be useful to assess the safety profile in an large cohort of patients.

Individual Article: Evaluation of Efficacy and Tolerability of Two Over-the-Counter Eczema Itch Relief Products.

BACKGROUND: Study to compare efficacy, tolerability, and patient perception between an over-the-counter itch relief gel (IRG) and itch relief moisturizing cream (IRMC) after a single application.  Methods: Single-center, randomized, blinded, split-body study comparing IRG vs IRMC in adults with eczema-prone skin and mild-to-moderate itch. Assessments included itch relief duration upon application, itch severity (0=none to 9=severe at baseline [BL], 8, 12, and 24 hours), tolerability (0=none to 3=severe), and self-assessment questionnaire about product attributes and preference.  Results: Thirty-three females and males with a mean age of 49.7 completed the study. Average time to itch relief was 28.5 seconds for IRG vs 41.8 for IRMC (P<0.05), with first onset at 5 seconds. In the IRG group, itch severity was reduced from 4.4 at BL to 1.4 at 8 hours; in comparison, itch was reduced from 4.4 at BL to 2.6 at 8 hours in the IRMC group (P<0.05). Both products significantly relieved itch vs baseline at all time points. IRG had better tolerability, with burning/stinging going from 1.5 at BL to 0.8 at 24 hours vs 1.5 at BL to 1.2 at 24 hours for IRMC (P<0.05). There was a trend in favor of IRG vs IRMC on the patient satisfaction self-assessment questionnaire. CONCLUSIONS: IRG provided rapid itch relief and significantly outperformed IRMC. Both products significantly improved itch severity for up to 24 hours after application, with IRG outperforming IRMC at 8 hours. Additionally, IRG moderated stinging/burning sensations better than IRMC. Further, IRG was preferred by participants over IRMC.J Drugs Dermatol. 2023;22:10(Suppl 2):s10-15.  .

Development of Bitter-Taste Masked Instant Jelly Formulations of Diphenhydramine Hydrochloride with Easy-to-Consume Granules.

This study developed easy-to-consume bitter taste-masking granules for the preparation of instant jelly formulations. Composite granules containing diphenhydramine hydrochloride (DPH) and polymers were prepared via spray drying. The taste-masking effect on DPH was evaluated with acceptable linearity between DPH concentration and intensity of bitterness using an electronic tongue sensor. The results indicated that ι-carrageenan could provide the greatest suppression effect on the DPH bitterness among the polymers selected for preparing spray-dried particles (SDPs). The thixotropic index (TI) of ι-carrageenan was higher than that of the other polymers. In addition, two sulfate groups per two galactose molecules in one unit of ι-carrageenan improved interaction with DPH. Compared to κ-carrageenan, the electrostatic interaction with DPH may be stronger. Easy-to-consume SDPs with ι-carrageenan were used to prepare instant jelly formulations. The instant jelly formulation containing DPH with ι-carrageenan (3.0%) met the criteria for texture properties (hardness, adhesiveness, and cohesiveness) for patients with difficulty swallowing, as specified by the Consumer Affairs Agency. Furthermore, instant jelly enhanced the bitter taste suppression of DPH. Overall, using spray-dried granules with ι-carrageenan, this technique for preparing instant jelly formulations is simple and inhibits the bitter taste of drugs, contributing to the development of oral dosage forms suitable for patients of all ages.

Evaluation of subchronic toxicity of the compound of diphenhydramine hydrochloride and caffeine after 28 days of repeated oral administration in Sprague-Dawley rats and beagle dogs.

This study was designed to evaluate the subchronic toxicity of the compound of diphenhydramine hydrochloride (DH) and caffeine in Sprague-Dawley (SD) rats and beagle dogs. A total of 180 SD rats (15/sex/group) were randomly divided into the compound low-, medium- and high-dose groups (51, 102, 204 mg/kg), DH group (60 mg/kg), caffeine group (144 mg/kg) and the vehicle control group. Sixty beagle dogs (5/sex/group) were randomly divided into the compound low-, medium- and high-dose groups (male: 14.20, 28.30, 56.60 mg/kg, female: 5.66, 14.20, 28.30 mg/kg), DH group (male: 16.60 mg/kg, female: 8.30 mg/kg), caffeine group (male: 40.00 mg/kg, female: 20.00 mg/kg) and the vehicle control group. Rats and dogs were given continuous oral administration for 28 days following a 28-day recovery period. The adverse effects of the compound on rats and beagle dogs mainly included anorexia and liver function impairment. Most adverse effects induced by administration were reversible. Under the experimental conditions, the no-observed-adverse-effect level (NOAEL) of the compound of DH and caffeine was 51 mg/kg/day for SD rats and 28.30 mg/kg/day (male) and 5.66 mg/kg/day (female) for beagle dogs.

Comparison of the preventive effect of colchicine versus diphenhydramine, prednisolone, and a combination therapy on intraperitoneal adhesion bands: an experimental study in rats.

BACKGROUND: Peritoneal adhesion formation is an inevitable consequence of abnormal repair of the peritoneum following different peritoneal injuries of intra-abdominal operations with the subsequent morbidity that they represent. Vast efforts have been made to elucidate the cause and prevent the development of abdominal adhesions. The aim of our study is to compare the capability of colchicine versus diphenhydramine (DPH) and methylprednisolone (MP), and also prednisolone in adhesion prevention. METHODS: Sixty-one male Wistar stock rats were divided into four groups. The first group attended as the control group. Groups 2, 3, and 4 received oral combination of MP + DPH solution (20 mg/kg), colchicine (0.02 mg/kg), and prednisolone (1 mg/ kg), respectively. Adhesion bands were induced by standardized abrasion of the peritoneum through a midline laparotomy. All rats were sacrificed on the 15th-day post medication administration and the subjects underwent an exploratory laparotomy. The presence of adhesions was evaluated with the modified using Nair's classification. RESULTS: The proportion of the control group with substantial adhesion bands (73.3%) was significantly higher than that of the MP + DPH (13.3%), colchicine (33.3%), and prednisolone (31.3%) groups. There were significant differences between the scores of the control and the MP + DPH, colchicine, and prednisolone groups (P = 0.001, 0.028, and 0.019, respectively). There was no statistically significant difference to favor colchicine against MP + DPH (P = 0.390) or MP + DPH against prednisolone (P = 0.394). CONCLUSIONS: Both colchicine and combination of DPH + MP prevented postoperative abdominal adhesions separately in our study. However, the lowest adhesion formation rate was observed in the DPH + MP group, even lower than the prednisolone group.

Chitosan-coated alginate (CCA) nanoparticles for augmentation of topical antihistaminic activity of diphenhydramine: in-vitro optimization, skin histopathology and pharmacodynamic studies with in vitro/in vivo correlation.

OBJECTIVE: The aim of the present study was to formulate chitosan-coated alginate nanoparticles containing the drug diphenhydramine hydrochloride (DHH). SIGNIFICANCE: Diphenhydramine hydrochloride (DHH) is the prototype of H1-antihistaminic drugs. It is a lipophilic drug, that easily crosses the blood-brain barrier when taken orally causing decrements in alertness and performance. Multiple applications of topical drug products are required. Thus, drug incorporation in nanocarriers would increase the skin penetration powers increasing the drug efficacy. METHODS: Chitosan-coated alginate (CCA) nanoparticles were prepared via polyelectrolyte complex technique adopting 23 full factorial designs. Three factors, namely, alginate concentration, drug-to-alginate ratio and CaCl2 volume, each in two levels were studied. The prepared formulae were evaluated utilizing entrapment efficiency (EE), particle size (PS), polydispersity index (PDI), zeta potential (ZP) and in vitro release. The characterization process was then followed by optimization. RESULTS: At alginate conc. of 1%, drug to alginate ratio of 2:1 and CaCl2 volume of 4 mL, NP8 was chosen as a candidate formula. Histopathological examination on shaved rat dorsal skin disclosed the safety of NP8 with no signs of necrosis or even inflammation. The enhanced topical delivery of diphenhydramine hydrochloride enclosed in the developed nanoparticles was further proved by induction of allergic reaction using intradermal histamine injection. The results revealed the superior ability of NP8 to decrease the diameter of the formed wheal in comparison to the marketed DHH product. CONCLUSION: Thus, CCA nanoparticles are considered candidate nanocarriers for fortifying the topical antihistaminic activity of DHH.

Sigma Receptor Ligands Prevent COVID Mortality In Vivo: Implications for Future Therapeutics.

The emergence of lethal coronaviruses follows a periodic pattern which suggests a recurring cycle of outbreaks. It remains uncertain as to when the next lethal coronavirus will emerge, though its eventual emergence appears to be inevitable. New mutations in evolving SARS-CoV-2 variants have provided resistance to current antiviral drugs, monoclonal antibodies, and vaccines, reducing their therapeutic efficacy. This underscores the urgent need to investigate alternative therapeutic approaches. Sigma receptors have been unexpectedly linked to the SARS-CoV-2 life cycle due to the direct antiviral effect of their ligands. Coronavirus-induced cell stress facilitates the formation of an ER-derived complex conducive to its replication. Sigma receptor ligands are believed to prevent the formation of this complex. Repurposing FDA-approved drugs for COVID-19 offers a timely and cost-efficient strategy to find treatments with established safety profiles. Notably, diphenhydramine, a sigma receptor ligand, is thought to counteract the virus by inhibiting the creation of ER-derived replication vesicles. Furthermore, lactoferrin, a well-characterized immunomodulatory protein, has shown antiviral efficacy against SARS-CoV-2 both in laboratory settings and in living organisms. In the present study, we aimed to explore the impact of sigma receptor ligands on SARS-CoV-2-induced mortality in ACE2-transgenic mice. We assessed the effects of an investigational antiviral drug combination comprising a sigma receptor ligand and an immunomodulatory protein. Mice treated with sigma-2 receptor ligands or diphenhydramine and lactoferrin exhibited improved survival rates and rapid rebound in mass following the SARS-CoV-2 challenge compared to mock-treated animals. Clinical translation of these findings may support the discovery of new treatment and research strategies for SARS-CoV-2.

Percutaneous absorption and Skin accumulation of Lorazepam-Diphenhydramine- Haloperidol Carbopol gel in Porcine Ear Skin.

This study presents the formulation and evaluation of an ABH Carbopol gel containing lorazepam (Ativan®), diphenhydramine hydrochloride (Benadryl®), and haloperidol (Haldol®) for treating chemotherapy-induced nausea and vomiting (CINV) in hospice patients. ABH PLO gel is widely used for this purpose due to its low cost and presumed efficacy. However, previous studies, including one conducted by the authors, have reported insufficient drug absorption from the ABH PLO gel. Here we hypothesized that the ABH Carbopol gel would provide superior percutaneous absorption of the drugs. ABH Carbopol gel was characterized for pH, viscosity, thermal properties, and infrared spectroscopy. The percutaneous absorption and skin retention of the gel was evaluated across porcine ear skin using Franz diffusion cells, and the drug concentrations were determined by high-performance liquid chromatography. The pH of the ABH Carbopol gel was found to be 6.80 ± 0.33, and the retention time of diphenhydramine, haloperidol, and lorazepam were 4.73, 7.11, and 18.69 minutes, respectively. The thermogram of the ABH Carbopol gel indicates the drugs were present in the dissolved state. Based on the flux data, the estimated steady-state concentration (Css) of diphenhydramine, haloperidol, and lorazepam were found to be 44.64 ng/ml, 2.58 ng/ml, and 20.1 ng/ml, respectively. These values were significantly higher than those obtained from the ABH PLO gel. In conclusion, the ABH Carbopol gel provides a promising alternative to the ABH PLO gel for treating CINV in hospice patients. Further studies are required to validate these findings in clinical settings.

A Hematological and Histopathological Study on Diphenhydramine Nasal Nano-gel and Nano-emulgel for the Management of Allergic Rhinitis in Animal Model.

The study aims to determine histamine efficacy on hematologic values in experimental animal model, under physiological and pathological conditions after inducing diphenhydramine-formulated nasal nano-gel/nano-emulgel in comparison with conventional nasal spray regime. In this study, we conducted experiment on New Zealand white male rabbits to prove our hypothesis that nasal diphenhydramine nano-gel and nano-emulgel can penetrate the nasal mucosa faster to show drug response and subside histaminic symptoms than market nasal spray (as reference). Blood samples from 48 New Zealand white male rabbits, under both experimental conditions (physiological and pathological) divided into four groups for each (n = 6) were investigated after inducing each dosage form intranasally. Hematologic parameters (WBCs, RBCs, HGB, PLTs, lymphocytes, monocytes, eosinophils, granulocyte counts) were analyzed in whole blood samples, collected at different time intervals. ANOVA and completely randomized design (CRD) were applied for statistical analysis. Histopathologically, nasal tissues of all groups were analyzed to see intramucosal surface changes. Data of descriptive statistics of hematological parameters analyzed at confidence level 95% showed that under physiological condition, hematological parameters of all groups were lying in normal range, whereas under pathological condition, low values of all hematological parameters were observed in all groups due to allergenic condition. The groups B (allergenic rabbits treated with formulated diphenhydramine nasal nano-gel) and C (allergenic rabbits treated with formulated diphenhydramine nasal nano-emulgel) have shown good changes in the treatment of allergenic rabbits as compared to group D (allergenic rabbits treated with formulated diphenhydramine nasal spray). The completely randomized ANOVA and Tukey HSD all-pairwise comparison tests of hematological parameters were applied that showed all groups in both studies were significantly different from each other. It was observed after histopathological study of nasal membrane tissues that change in mucosa has occurred due to the passage of drug. In summary, hematological profile and histopathological study have demonstrated the comparable results with conventional diphenhydramine nasal spray and formulated diphenhydramine nasal nano-gel/nano-emulgel which can exhibit considerable drug delivery dosage forms in the management of allergic rhinitis in animal model.

The short third intracellular loop and cytoplasmic tail of bitter taste receptors provide functionally relevant GRK phosphorylation sites in TAS2R14.

For most G protein-coupled receptors, the third intracellular loop (IL3) and carboxy-terminal tail (CT) are sites for G protein-coupled receptor kinase (GRK)-mediated phosphorylation, leading to ß-arrestin binding and agonist-specific desensitization. These regions of bitter taste receptors (TAS2Rs) are extremely short compared with the superfamily, and their function in desensitization is unknown. TAS2R14 expressed on human airway smooth muscle cells relax the cell, suggesting a novel target for bronchodilators. To assess IL3 and CT in agonist-promoted TAS2R14 desensitization (tachyphylaxis), we generated fusion proteins of both the WT sequence and Ala substituted for Ser/Thr in the IL3 and CT sequences. In vitro, activated GRK2 phosphorylated WT IL3 and WT CT proteins but not Ala-substituted forms. TAS2R14s with mutations in IL3 (IL-5A), CT (CT-5A), and in both regions (IL/CT-10A) were expressed in human embryonic kidney 293T cells. IL/CT-10A and CT-5A failed to undergo desensitization of the intracellular calcium response compared with WT, indicating that functional desensitization by GRK phosphorylation is at residues in the CT. Desensitization of TAS2R14 was blocked by GRK2 knockdown in human airway smooth muscle cells. Receptor:ß-arrestin binding was absent in IL/CT-10A and CT-5A and reduced in IL-5A, indicating a role for IL3 phosphorylation in the ß-arrestin interaction for this function. Agonist-promoted internalization of IL-5A and CT-5A receptors was impaired, and they failed to colocalize with early endosomes. Thus, agonist-promoted functional desensitization of TAS2R14 occurs by GRK phosphorylation of CT residues and ß-arrestin binding. However, ß-arrestin function in the internalization and trafficking of the receptor also requires GRK phosphorylation of IL3 residues.