Yohimbine

INTRODUCTION: The efficacy and safety of arginine supplements in erectile dysfunction (ED) remain debatable. AIM: To assess the potential role of arginine supplements on ED as alternatives to phosphodiesterase inhibitors. METHODS: Studies published up to April 2018 that evaluated the efficacy of arginine supplements were identified from multiple databases (Google Scholar, PubMed, Medline, Embase, Kiss, DBpia, and Cochrane databases). Studies comparing arginine supplements with placebo or no treatment; focusing only on patients with mild to moderate severity of ED; and presenting outcomes such as improvement rate, International Index of Erectile Function (IIEF) score, and adverse effects were included. Subgroup analysis for arginine alone and arginine in combination with other substances was further conducted to increase interpretability. MAIN OUTCOME MEASURE: The strength of the association between arginine supplements and ED was assessed using relative odds ratios and weighted mean differences with 95% CI. RESULTS: In total, 10 randomized controlled trials met the inclusion criteria, reporting the outcomes of 540 patients with ED. The analysis demonstrated that arginine supplements with dosage ranging from 1,500 to 5,000 mg significantly improved ED compared with placebo or no treatment (odds ratios, 3.37 [1.29, 8.77], P = .01, I2 = 44). Arginine supplements also caused significant improvements in the IIEF subdomain scores of overall satisfaction, intercourse satisfaction, orgasmic function, and erectile function, whereas the IIEF sexual desire score remain unchanged. The adverse effect rate in the arginine-treated group was 8.3%, and that in the placebo group was 2.3%, none of which were severe. CLINICAL IMPLICATIONS: Arginine supplements can be recommended to patients with mild to moderate ED. STRENGTH & LIMITATIONS: The strength of this study is that it is the first meta-analysis to assess the potential role of arginine supplements in ED compared with placebo or no treatment. A limitation is that the treatment dosage and duration varied among studies, which may have contributed to study heterogeneity. CONCLUSION: The results of our systematic review and meta

BACKGROUND: Obesity is closely related to type 2 diabetes and long-term weight reduction is an important part of the care delivered to obese persons with diabetes. OBJECTIVES: To assess the efficacy of pharmacotherapy for weight loss in adults with type 2 diabetes. SEARCH STRATEGY: Computerized searches were performed of MEDLINE (January 1966 to May 2004), EMBASE (January 1974 to May 2004, Web of Science (January 1981 to May 2004, and other electronic bibliographic databases, supplemented with hand searches of reference lists and selected journals. SELECTION CRITERIA: Randomized, controlled trials were included where pharmacotherapy was used as the primary strategy for weight loss among adults with type 2 diabetes. Published and unpublished literature in any language and with any study design was included. DATA COLLECTION AND ANALYSIS: Two reviewers abstracted data and the quality of included studies was evaluated by assessing potential attrition, as well as selection and measurement bias, and a Jadad score was obtained. Effects were combined using a random effects model. MAIN RESULTS: A sufficient number of studies were available for a quantitative synthesis for fluoxetine, orlistat, and sibutramine. Twenty two randomized controlled trials were included in the review, with a total of 296 participants for fluoxitine, 2036 for orlistat, and 1047 for sibutramine. Pharmacotherapy produced modest reductions in weight for fluoxetine (5.1 kg (95% confidence interval [CI], 3.3 - 6.9) at 24 to 26 weeks follow up; orlistat 2.0 kg (CI, 1.3 - 2.8) at 12 to 57 weeks follow-up, and sibutramine 5.1 kg (CI, 3.2 - 7.0) at 12 to 52 weeks follow-up. Glycated hemoglobin also modestly and significantly reduced for fluoxetine and orlistat. Gastrointestinal side effects were common with orlistat; tremor, somnolence and sweating with fluoxetine; and palpitations with sibutramine. Some studies, using a variety of study designs, were available on other drugs and a significant decrease in weight was noted in three studies of mazindol, one of phenmetrazine, two of phentermine. No studies were identified that fit inclusion criteria for pseudophedrine, ephedra, sertraline, yohimbine, amphet

Stress changes social behavior, yet its effects remain contradictory. Traditionally, stress was thought to trigger an antagonistic fight-or-flight response aimed at eliminating the stressor. However, recent studies have revealed the opposite response, tend-and-befriend, where individuals prosocially invest in their social network in exchange for support and mutual protection. We hypothesize that stress does not promote one response over the other; instead, it stimulates both behaviors, dissociable on the neuropharmacological level and moderated by social context. In a placebo-controlled, double-blind psychopharmacological study, we administered hydrocortisone and yohimbine-alone or in combination-to manipulate the actions of the main stress hormone cortisol and the arousal transmitter noradrenaline. Participants then made decisions in an intergroup conflict task. They teamed up with others to form an in-group and played against multiple out-groups. Notably, out-group members initiated financial harm to in-group participants before these responded. Participants then chose either to 1) maximize their own payoff, 2) cooperatively increase the payoff of their in-group, or 3) increase the in-group's payoff while competitively decreasing that of the out-group. Consistent with our hypotheses, glucocorticoid activation increased generosity toward the in-group, whereas noradrenergic activation increased parochial competition, i.e., prosocial in-group support combined with hostility toward the out-group. These findings challenge the dichotomy between fight-or-flight and tend-and-befriend, suggesting stress-related behavior is neither static nor one-directional, but shaped by the relative dominance of cortisol versus noradrenaline in the neurohormonal stress response and by intergroup dynamics. We highlight broader societal implications, offering a potential biological mechanism underlying the self-perpetuating cycle of intergroup conflict.

BACKGROUND: The human stress response is characterized by increases in neuromodulators, including norepinephrine (NE) and cortisol. Both neuromodulators can enter the brain and affect neurofunctional responses. Two brain areas associated with stress are the amygdala and the hippocampus. The precise influence of NE and cortisol on the amygdala and hippocampal resting state functional connectivity (RSFC) is poorly understood. AIMS: To investigate the influence of NE and cortisol on the amygdala and hippocampal RSFC. METHODS: We recruited 165 participants who received 10 mg yohimbine and/or 10 mg hydrocortisone in a randomized, placebo-controlled design. With seed-based analyses, we compared RSFC of the hippocampus and amygdala separately between the three groups that received medication versus placebo. RESULTS: We found no differences between yohimbine and placebo condition or between hydrocortisone and placebo condition regarding amygdala or hippocampal FC. Compared with placebo, the yohimbine/hydrocortisone condition showed increased amygdala and hippocampal RSFC with the cerebellum. Also, they had increased hippocampal RSFC with the amygdala and cerebral white matter. DISCUSSION: The group with elevated NE and cortisol showed significantly increased RSFC between the amygdala, hippocampus, and cerebellum compared to placebo. These three brain areas are involved in associative learning and emotional memory, suggesting a critical role for this network in the human stress response. Our results show that NE and cortisol together may influence the strength of this association. Compared to placebo, we found no differences in the groups receiving only one medication, suggesting that increasing one neuromodulator alone may not induce differences in neurofunctional responses. The study procedure has been registered at clinicaltrials.gov (ID: NCT04359147).

INTRODUCTION: Selective attention to salient emotional information can enable an advantage in the face of danger. The present study aims to investigate the influence of the stress neuromodulators, norepinephrine and cortisol, on selective attention processes to fearful faces and its neuronal activation. METHODS AND MATERIALS: We used a randomized, double-blind, placebo-controlled design. 167 healthy men between 18 and 35 years (mean [SD] age: 25.23 [4.24] years) participated in the study. Participants received either: (A) yohimbine (n= 41), (B) hydrocortisone (n = 41), (C) yohimbine and hydrocortisone (n = 42) or (D) placebo only (n= 43) and participated in a dot-probe task with fearful and neutral faces in an fMRI scanner. RESULTS: We found an attentional bias toward fearful faces across all groups and related neuronal activation in the left cuneus. We did not find any differences between experimental treatment groups in selective attention and its neuronal activation. DISCUSSION: Our results provide evidence that fearful faces lead to an attentional bias with related neuronal activation in the left cuneus. We did not replicate formerly reported activation in the amygdala, intraparietal sulcus, dorsal anterior cingulate cortex, and thalamus. Suitability of the dot-probe task for fMRI studies and insignificant treatment effects are discussed.

Successful recovery from stress is integral for adaptive responding to the environment. At a cellular level, this involves (slow genomic) actions of cortisol, which alter or reverse rapid effects of noradrenaline and cortisol associated with acute stress. At the network scale, stress recovery is less well understood but assumed to involve changes within salience-, executive control-, and default mode networks. To date, few studies have investigated this phase and directly tested these assumptions. Here, we present results from a double-blind, placebo-controlled, between-group paradigm (N = 165 healthy males) administering 10 mg oral yohimbine and/or 10 mg oral hydrocortisone two hours prior to resting state scanning. We found no changes in within-network connectivity of the three networks, both after single and combined drug administration. We further report the results of Bayesian parameter inference to provide evidence for the null hypothesis. Our results contrast with previous findings, which may be attributable to systematic differences between paradigms, highlighting the need to isolate paradigm-specific effects from those related to stress. © The Author(s) 2024. Published by Oxford University Press.

BACKGROUND AND OBJECTIVE: Although polypharmacy is a particular challenge in daily rheumatological practice, clinical research on the effects of hydroxychloroquine (HCQ), a commonly used drug for patients with rheumatic diseases, is sparse on cytochrome P450 (CYP)-mediated metabolism. We have shown that pre-treatment with pantoprazole does not alter HCQ absorption in healthy volunteers. In this paper, we report the effects of a single 400 mg dose of HCQ on specific CYP3A and CYP2D6 substrates in healthy volunteers. METHODS: In the trial, participants were randomized into two groups (HCQ plus a 9-day course of pantoprazole, or HCQ only). As a secondary endpoint, the effects of a single oral dose of HCQ on the exposure of the oral microdosed CYP3A probe drug midazolam (30 μg) and the oral microdosed CYP2D6 probe drug yohimbine (50 μg) were studied in 23 healthy volunteers (EudraCT no. 2020-001470-30, registered 31 March 2020). RESULTS: The exposure of the probe drugs after intake of HCQ compared with baseline values was quantified by the partial area under the plasma concentration-time curve 0-6 h after administration (AUC0-6 h) for yohimbine and the partial AUC2-4 h for midazolam. Under HCQ, yohimbine AUC0-6 h was unchanged, independent of CYP2D6 genotypes and pantoprazole exposure. Midazolam AUC2-4 h was 25% higher on the day of HCQ administration than at baseline (p = 0.0007). This significant increase was driven by the pantoprazole subgroup, which showed a 46% elevation of midazolam AUC2-4 h as compared with baseline (p < 0.0001). The ratio of midazolam to 1-OH-midazolam partial AUC2-4 h significantly increased from 3.03 ± 1.59 (baseline) to 3.60 ± 1.56 (HCQ) in the pantoprazole group (p = 0.0026). CONCLUSION: In conclusion, we observed an increased midazolam exposure most likely related to pantoprazole. © 2023. The Author(s).

Update of medRxiv. 2023 Jan 04:2023.01.02.23284122. doi: 10.1101/2023.01.02.23284122. Preclinical and clinical work suggests that mifepristone may be a viable treatment for alcohol use disorder (AUD). This was a Phase 1/2, outpatient, cross-over, randomized, double-blind, placebo-controlled trial with non-treatment-seeking individuals with AUD (N = 32). We assessed safety, alcohol craving and consumption, after 1-week mifepristone 600 mg/day administration, in a human laboratory study comprised of a single oral yohimbine administration (32.4 mg), a cue-reactivity procedure and alcohol self-administration. Safety was monitored by adverse events and hemodynamic parameters, alcohol craving by alcohol craving questionnaire and cue-induced saliva output. During the alcohol self-administration, we assessed alcohol pharmacokinetics, subjective effects and consumption. Outcomes were assessed using Generalized Estimating Equations and mediation analysis. Mild-moderate adverse events were reported in both conditions. There was no statistically significant difference between mifepristone and placebo in alcohol pharmacokinetics and subjective effects. Furthermore, blood pressure increased only in the placebo condition after the stress-induced laboratory procedures. Mifepristone, compared to placebo, significantly reduced alcohol craving and increased cortisol levels. Mifepristone-induced cortisol increase was not a mediator of alcohol craving. Mifepristone, compared to placebo, did not reduce alcohol consumption in the laboratory or in a naturalistic setting. This study successfully translated a developed preclinical procedure to a human laboratory study, confirming the safety of mifepristone in people with AUD and providing evidence to its role in reducing alcohol craving under stress procedures. The lack of effects on alcohol drinking may be related to the selection of non-treatment seekers and suggests future treatment-oriented trials should investigate mifepristone in people with AUD. © 2023 Society for the Study of Addiction.

RATIONALE: Balancing approach of positive and avoidance of negative stimuli is essential when faced with approach-avoidance conflicts, e.g., situations with both positive and negative outcomes. This balance is disturbed in several mental disorders, e.g., excessive avoidance in anxiety disorders, and heightened approach in substance use disorders. Since stress is assumed to impact these disorders' etiology and maintenance, it seems crucial to understand how stress influences behavior in approach-avoidance conflicts. Indeed, some studies suggested altered approach-avoidance behavior under acute stress, but the mechanism underlying these effects is unknown. OBJECTIVES: Investigate how the pharmacological manipulation of major stress mediators (cortisol and noradrenaline) influences task-based approach-avoidance conflict behavior in healthy individuals. METHODS: Ninety-six participants (48 women, 48 men) received either 20mg hydrocortisone, 20mg yohimbine, both, or placebo before performing a task targeting foraging under predation in a fully crossed double-blind between-subject design. Moreover, we investigated effects of gender and endogenous testosterone and estradiol levels on approach-avoidance behavior. RESULTS: While biological stress markers (cortisol concentration, alpha amylase activity) indicated successful pharmacological manipulation, behavior in approach-avoidance conflicts was not affected as expected. Although yohimbine administration affected risky foraging latency under predation, we found no main effect of hydrocortisone or their interaction on behavior. In contrast, we found gender differences for almost all behavioral outcome measures, which might be explained by differences in endogenous testosterone levels. CONCLUSIONS: The investigated major stress mediators were not sufficient to imitate previously shown stress effects on approach-avoidance conflict behavior. We discuss potential reasons for our findings and implications for future research. © 2023. The Author(s).

BACKGROUND: Hyperconsolidation of aversive associations and poor extinction learning have been hypothesized to be crucial in the acquisition of pathological fear. Previous animal and human research points to the potential role of the catecholaminergic system, particularly noradrenaline and dopamine, in acquiring emotional memories. Here, we investigated in a between-participants design with 3 groups whether the noradrenergic alpha-2 adrenoreceptor antagonist yohimbine and the dopaminergic D2-receptor antagonist sulpiride modulate long-term fear conditioning and extinction in humans. METHODS: Fifty-five healthy male students were recruited. The final sample consisted of n = 51 participants who were explicitly aware of the contingencies between conditioned stimuli (CS) and unconditioned stimuli after fear acquisition. The participants were then randomly assigned to 1 of the 3 groups and received either yohimbine (10 mg, n = 17), sulpiride (200 mg, n = 16), or placebo (n = 18) between fear acquisition and extinction. Recall of conditioned (non-extinguished CS+ vs CS-) and extinguished fear (extinguished CS+ vs CS-) was assessed 1 day later, and a 64-channel electroencephalogram was recorded. RESULTS: The yohimbine group showed increased salivary alpha-amylase activity, confirming a successful manipulation of central noradrenergic release. Elevated fear-conditioned bradycardia and larger differential amplitudes of the N170 and late positive potential components in the event-related brain potential indicated that yohimbine treatment (compared with a placebo and sulpiride) enhanced fear recall during day 2. CONCLUSIONS: These results suggest that yohimbine potentiates cardiac and central electrophysiological signatures of fear memory consolidation. They thereby elucidate the key role of noradrenaline in strengthening the consolidation of conditioned fear associations, which may be a key mechanism in the etiology of fear-related disorders. © The Author(s) 2022. Published by Oxford University Press on behalf of CINP.

RATIONALE: Pre-ejection period (PEP) and T-wave amplitude (TWA) have been used to assess sympathetic nervous system (SNS) activity. Here we report two single-blinded, placebo-controlled intravenous (IV) drug application studies in which we pharmacologically modified SNS activity with epinephrine (study 1) as well as dexmedetomidine (alpha2-agonist) and yohimbine (alpha2-antagonist) (study 2). Restricted heart rate (HR) intervals were analyzed to avoid confounding effects of HR changes. OBJECTIVE: Study 1 served to replicate previous findings and to validate our approach, whereas study 2 aimed to investigate how modulation of central SNS activity affects PEP and TWA. METHODS: Forty healthy volunteers (58% females) participated in study 1 (between-subject design). Twelve healthy men participated in study 2 (within-subject design). TWA and PEP were derived from ECG and impedance cardiography, respectively. RESULTS: Epinephrine shortened PEP and induced statistically significant biphasic TWA changes. However, although the two alpha2-drugs significantly affected PEP as expected, no effects on TWA could be detected. CONCLUSION: PEP is better suited to reflect SNS activity changes than TWA. © 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

The purpose of this study was to examine the effects of a single acute dose of yohimbine hydrochloride on repeated anaerobic sprint ability. Physically active females (n = 18) completed two separate repeated supramaximal sprint trials each with a different single-dose treatment: placebo (PL; gluten-free corn starch) or yohimbine hydrochloride (YHM; 2.5 mg). For each trial, participants consumed their respective treatment 20 min before exercise. Following a warm-up, participants completed 3 × 15 s Wingate anaerobic tests (WAnTs) separated by 2 min of active recovery. A capillary blood sample was obtained pre- and immediately post-exercise to measure blood concentrations of lactate (LA), epinephrine (EPI), and norepinephrine (NE). Heart rate (HR) and rate of perceived exertion (RPE) were measured following each WAnT. Findings showed that mean power (p < 0.001; η2 = 0.024), total work (p < 0.001; η2 = 0.061), and HR (p < 0.001; η2 = 0.046), were significantly higher with YHM supplementation versus PL. Fatigue index (p < 0.001; η2 = 0.054) and post-exercise LA (p < 0.001; d = 1.26) were significantly lower with YHM compared to PL. YHM resulted in significantly higher EPI concentrations versus PL (p < 0.001; η2 = 0.225) pre- and post-exercise while NE only increased as a function of time (p < 0.001; η2 = 0.227) and was unaffected by treatment. While RPE increased after each WAnT, no differences between treatments were observed (p = 0.539; η2 < 0.001). Together, these results suggest that acute YHM ingestion imparts ergogenic benefits which may be mediated by lower blood LA and fatigue concomitantly occurring with blood EPI increases. Thus, YHM may improve sprint performance although more mechanistic study is warranted to accentuate underlying processes mediating performance enhancement.

Yohimbine is a food supplement that is also used to treat erectile dysfunction. It has recently been introduced as a probe drug to assess the activity of cytochrome P450 (CYP) 2D6. This in vitro study investigated possible substrate and inhibitor properties of yohimbine for drug transporters and inhibitor properties for CYPs to assess, whether yohimbine might be prone to drug-drug interactions. Inhibition of P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), organic anion transporting polypeptides (OATPs) and organic cation transporters (OCTs) was tested by using probe substrates and transporter-overexpressing cell lines. The potential substrate properties of yohimbine for P-gp and OCTs were tested in accumulation assays in different cell lines with and without overexpression of the respective transporter. Inhibition of CYPs was assessed by using luminogenic substrates. The interaction of yohimbine with OCTs was evaluated in silico using docking analyses. Yohimbine did not inhibit P-gp, BCRP, OATP 1B1, 1B3 and 2B1. It was described and characterised in vitro and in silico as a good substrate of OCT1-3 (Km between 3.7 and 6.2 μM) and a weak inhibitor of OCT2 and OCT3 with IC50 values in the upper micromolar range. Yohimbine potently inhibited CYP2D6 with an IC50 of 0.31 μM, weakly inhibited CYP1A2, CYP2C19, and CYP3A4, and did not inhibit CYP2B6. In conclusion, we have verified that yohimbine inhibits CYP2D6 and demonstrated that it is a substrate of OCT1, OCT2, and OCT3, a weak inhibitor of OCT2 and OCT3, but does not inhibit P-gp, BCRP, OATP1B1, OTP1B3, OATP2B1, and OCT1. Synergistic interaction between clonidine and ACPA on the modulation of anxiety-like behaviors in non-acute restraint stress and acute restraint stress conditions. Chitsaz A(1), Ebrahimi-Ghiri M(2), Zarrindast MR(3), Khakpai F(4). Author information: (1)Department of Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. (2)Department of Biology, Faculty of Sciences, University of Zanjan, Zanjan, Iran. (3)Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Iranian National Center for Ad

14. Brain Res. 2025 Jan 15;1847:149304. doi: 10.1016/j.brainres.2024.149304. Epub 2024 Oct 29. Synergistic interaction between clonidine and ACPA on the modulation of anxiety-like behaviors in non-acute restraint stress and acute restraint stress conditions. Chitsaz A(1), Ebrahimi-Ghiri M(2), Z

AIMS: Clomipramine (CLOMI) has shown effectiveness in treating premature ejaculation but is linked to erectile dysfunction and reduced libido. Yohimbine (YOH), by contrast, is effective in treating erectile dysfunction and may improve libido. Combining CLOMI and YOH could potentially leverage the benefits of both drugs. This study aimed to investigate the interactions between these drugs and to evaluate their safety profile. METHODS: A prospective, open-labelled, single-centre, pharmacokinetic (PK) drug-drug interaction study was performed in 15 healthy male subjects. Single-dose and steady-state PK were investigated using noncompartmental analysis after mono- and combination therapy of the 2 orally applied drugs. Plasma sampling was performed at baseline, 0.5 (YOH), 1, 1.5 (YOH), 2, 3, 4, 5, 6, 8, 12 and 24 h (CLOMI). Differences in the area under the curve after multiple dosing (MD) were determined using an equivalence boundary of 80-125%. RESULTS: The geometric mean ratio of the area under the curve up to 12 h for MD CLOMI (combination vs. monotherapy) was 112% (90% confidence interval: 104-120%), whereas for MD YOH this ratio was 137% (90% confidence interval: 112-168%). The study drugs were safe and well tolerated as mono- and combination therapy, with no major adverse events reported. CONCLUSION: A PK assessment of clomipramine and yohimbine indicated a clinically significant drug-drug interaction for MD YOH in combination with CLOMI. This might be explained by competitive, CLOMI-related inhibition of YOH metabolism, probably mediated by cytochrome P450 2D6. However, according to European Medicines Agency guidelines, the effect can be classified as interaction absent (<1,25 fold) or minor (>1.25-<2-fold). Given the complimentary mechanisms of action and the favourable safety profiles, the findings pave the way for future efficacy studies. © 2024 British Pharmacological Society.

BACKGROUND: We investigated the effect of a 5-day low-dose ritonavir therapy, as it is used in the treatment of COVID-19 with nirmatrelvir/ritonavir, on the pharmacokinetics of three factor Xa inhibitors (FXaI). Concurrently, the time course of the activities of the cytochromes P450 (CYP) 3A4, 2C19, and 2D6 was assessed. METHODS: In an open-label, fixed sequence clinical trial, the effect and duration of a 5-day oral ritonavir (100 mg twice daily) treatment on the pharmacokinetics of three oral microdosed FXaI (rivaroxaban 25 µg, apixaban 25 µg, and edoxaban 50 µg) and microdosed probe drugs (midazolam 25 µg, yohimbine 50 µg, and omeprazole 100 µg) was evaluated in eight healthy volunteers. The plasma concentrations of all drugs were quantified using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods and pharmacokinetics were analysed using non-compartmental analyses. RESULTS: Ritonavir increased the exposure of apixaban, edoxaban, and rivaroxaban, but to a different extent the observed area under the plasma concentration-time curve (geometric mean ratio 1.29, 1.46, and 1.87, respectively). A strong CYP3A4 inhibition (geometric mean ratio > 10), a moderate CYP2C19 induction 2 days after ritonavir (0.64), and no alteration of CYP2D6 were observed. A CYP3A4 recovery half-life of 2.3 days was determined. CONCLUSION: This trial with three microdosed FXaI suggests that at most the rivaroxaban dose should be reduced during short-term ritonavir, and only in patients receiving high maintenance doses. Thorough time series analyses demonstrated differential effects on three different drug-metabolising enzymes over time with immediate profound inhibition of CYP3A4 and only slow recovery after discontinuation. CLINICAL TRIAL REGISTRATION: EudraCT number: 2021-006643-39. © 2024. The Author(s).

PURPOSE: To investigate the suitability of microdosed oral omeprazole for predicting CYP2C19 activity in vivo in combination with simultaneous assessment of CYP3A and CYP2D6 activity using both microdosed midazolam and yohimbine. METHODS: An open, fixed-sequence study was carried out in 20 healthy participants. Single microdosed (100 µg) and therapeutic (20 mg) doses of omeprazole were evaluated without comedication and after administration of established CYP2C19 perpetrators fluconazole (inhibition) and rifampicin (induction). To prevent degradation of the uncoated omeprazole microdose, sodium bicarbonate buffer was administered. The pharmacokinetics of omeprazole and its 5-hydroxy-metabolite were assessed as well as the pharmacokinetics of midazolam and yohimbine to estimate CYP3A4 and CYP2D6 activity. RESULTS: Calculated pharmacokinetic parameters after administration of 100 µg and 20 mg omeprazole in healthy subjects suggest dose proportionality. Omeprazole clearance was significantly decreased by fluconazole from 388 [95% CI: 266-565] to 47.2 [42.8-52.0] mL/min after 20 mg omeprazole and even further after 100 µg omeprazole (29.4 [24.5-35.1] mL/min). Rifampicin increased CYP2C19-mediated omeprazole metabolism. The omeprazole hydroxylation index was significantly related to omeprazole clearance for both doses. Both fluconazole and rifampicin altered CYP3A4 activity whereas no change of CYP2D6 activity was observed at all. CONCLUSIONS: Microdosed oral omeprazole is suitable to determine CYP2C19 activity, also during enzyme inhibition and induction. However, the administration of sodium bicarbonate buffer also had a small influence on all victim drugs used. TRIAL REGISTRATION: EudraCT: 2017-004270-34. © 2022. The Author(s).

AIMS: Dezocine and pentazocine, widely prescribed in China for postoperative pain, were initially considered as mixed agonist/antagonist targeting μ-opioid receptors (MORs) and κ-opioid receptors (KORs). However, dezocine has been revealed to alleviate chronic neuropathic pain through MOR activation and norepinephrine reuptake inhibition (NRI). This study investigated dezocine- and pentazocine-induced antinociception and physical dependence development, compared to the typical MOR-NRI opioid tapentadol. MAIN METHODS: Calcium mobilization assay was conducted to assess the potency of the drugs while hot-plate test was performed to compare the antinociception. Physical dependence development was compared with morphine. KEY FINDINGS: Treatment with dezocine, pentazocine and tapentadol stimulated calcium mobilization in HEK293 cells stably expressed MORs but not KORs, whereas dezocine and pentazocine inhibited KOR activities. Subcutaneously injected dezocine-, tapentadol- and pentazocine-induced antinociception dose-dependently, in hot-plate test. Intrathecally injected MOR antagonist CTAP, norepinephrine depletor 6-OHDA and α2-adrenoceptor (α2-AR) antagonist yohimbine partially antagonized dezocine, pentazocine and tapentadol antinociception. Whereas specific KOR antagonist GNTI did not alter their antinociception, the putative inverse KOR agonist nor-BNI reduced dezocine and pentazocine antinociception. Moreover, combined CTAP and 6-OHDA or yohimbine blocked dezocine and tapentadol antinociception but displayed the same partial inhibition on pentazocine antinociception as CTAP alone. Furthermore, compared to morphine and pentazocine, long-term treatment with dezocine and tapentadol produced much less physical dependence-related withdrawal signs, which were restored by spinal 6-OHDA or yohimbine treatment. SIGNIFICANCE: Our findings illustrated that dezocine and tapentadol, but not pentazocine, exert remarkable antinociception in nociceptive pain with less abuse liability via dual mechanisms of MOR activation and NRI.

Adrenergic β-blockers are used to treat many conditions, including hypertension, cardiac arrhythmias, heart failure, angina pectoris, migraine, and tremors. The majority of the β-blockers including Propranolol, Metoprolol, Acebutolol, Alprenolol, Betaxolol, Carvedilol, Nebivolol and Oxprenolol are metabolised majorly by CYP2D6, and Bisoprolol is primarily metabolised by CYP3A4 enzymes. The drugs inhibiting or inducing them may alter the pharmacokinetics of those β-blockers. The plasma concentrations of Propranolol might be elevated by the concomitant use of drugs, such as SSRIs (Fluoxetine, Paroxetine), SNRIs (Duloxetine) and Cimetidine, while the plasma concentrations of Metoprolol increased by the concurrent use of SSRIs (Fluoxetine, Paroxetine), Amiodarone, Celecoxib, Cimetidine, Terbinafine, and Diphenhydramine. β-blockers can also interact pharmacodynamically with drugs, including fluoroquinolones, antidiabetic agents and NSAIDs. In addition, β-blockers may interact with herbs, such as curcumin, Ginkgo biloba, Schisandra chinensis, green tea, guggul, hawthorn, St. John's wort and Yohimbine. This article focuses on clinically relevant drug interactions of β-blockers with commonly prescribed medications. In addition to Pharmacokinetics and Pharmacodynamics of the drug interactions, recommendations for clinical practice are highlighted. The prescribers and the pharmacists are needed to be aware of the drugs interacting with β-blockers to prevent possible adverse drug interactions.

A previous study demonstrated that glutathione (GSH) produces specific antidepressant-like effect in the forced swimming test (FST), a predictive test of antidepressant activity. The present study investigated the involvement of multiple cellular targets implicated in the antidepressant-like effect of GSH in the FST. The antidepressant-like effect of GSH (300 nmol/site, icv) lasted up to 3 h when mice were submitted to FST. The central administration of oxidized GSH (GSSG, 3-300 nmol/site) did not alter the behavior of mice submitted to the FST. Furthermore, the combined treatment of sub-effective doses of GSH (100 nmol/site, icv) with a sub-effective dose of classical antidepressants (fluoxetine 10 mg/kg, and imipramine 5 mg/kg, ip) presented synergistic effect by decreasing the immobility time in the FST. The antidepressant-like effect of GSH was abolished by prazosin (1 mg/kg, ip, α1-adrenoceptor antagonist), baclofen (1 mg/kg, ip, GABAB receptor agonist), bicuculline (1 mg/kg, ip, GABAA receptor antagonist), l-arginine (750 mg/kg, ip, NO precursor), SNAP (25 μg/site, icv, NO donor), but not by yohimbine (1 mg/kg, ip, α2-adrenoceptor antagonist). The NMDA receptor antagonists, MK-801(0.001 mg/kg, ip) or GMP (0.5 mg/kg, ip), potentiated the effect of a sub-effective dose of GSH in the FST. These results suggest that the antidepressant-like effect induced by GSH is connected to the activation of α1 adrenergic and GABAA receptors, as well as the inhibition of GABAB and NMDA receptors and NO biosyntesis. We speculate that redox-mediated signaling on the extracelular portion of cell membrane receptors would be a common mechanism of action of GSH.

OBJECTIVES: Primary objective: Evaluation of the effect of the proton pump inhibitor (PPI) pantoprazole on the absorption of hydroxychloroquine (HCQ). Secondary objectives: • Evaluation of the relationship between HCQ concentrations in whole blood, plasma and intracellular concentrations in target cells - peripheral blood mononuclear cells (PBMCs). • Evaluation of HCQ as a potential perpetrator in drug-drug interactions at the level of cytochrome P450 (CYP) 3A4 and CYP2D6 (major drug metabolizing enzymes). TRIAL DESIGN: Single centre, open-label, parallel group, two-arm, phase I drug-drug interaction trial. PARTICIPANTS: Healthy volunteers (18-60 years old) are treated in the Clinical Pharmacological Trial Center of Heidelberg University Hospital, Germany. INTERVENTION AND COMPARATOR: • Participants are randomized in a group to either receive a nine-day course of pantoprazole, or to a control group without pantoprazole. All participants receive a single dose of HCQ 400 mg. • Additionally, CYP3A4 and CYP2D6 phenotyping with microdosed probe drugs is performed using midazolam and yohimbine as enzyme activity markers, respectively. MAIN OUTCOMES: Primary endpoint: Area under the curve (AUC)0-72 h and maximum concentration (Cmax) of a single oral dose of 400 mg HCQ with and without pantoprazole (changes in these two values describe relevant aspects of exposure to HCQ with and without administration of pantoprazole). Secondary endpoints: • AUC2-4 h, AUC0-6 h and Cmax of midazolam and yohimbine. • Correlation of HCQ concentrations in whole blood with concentrations in plasma and peripheral blood mononuclear cells (PBMC). RANDOMISATION: Participants are assigned to treatment groups by using a randomisation list (1:1, block size = 4) and consecutive enrolment. BLINDING (MASKING): The trial is an open-label trial, participants and investigators are not blinded. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): A total number of 24 participants (12 per group) are planned to be randomised. TRIAL STATUS: Protocol version 2.1 dated 24/04/2020, first patient first visit. April 30th, 2020, recruitment ongoing, anticipated end of study June 30th, 2020. TRIAL REGISTRATION: EudraCT Number:

Evaluation and improvement of immobilization methods are important for wildlife welfare and biodiversity conservation. The sedative and physiological effects of xylazine (50-110 mg per elephant; 0.09-0.15 mg/kg IM) were evaluated in 15 juvenile Asian elephants (Elephas maximus) in Sri Lanka. The time from xylazine injection until first sign of sedation, handling, and reversal with yohimbine (0.009-0.03 mg/kg IV) were recorded. Behavioral signs, level of sedation (no effect, light, moderate, or deep) and response to handling were assessed. Rectal temperature, pulse, and respiratory rates were recorded and arterial blood samples were analyzed 30 and 45 min after xylazine injection. The first sign of sedation occurred within 5-18 min. Standing sedation was induced in all elephants, but the level of sedation varied differently over time for each elephant. Twelve elephants remained standing throughout the sedation period, while 3 elephants became laterally recumbent. Sedative effects included lowered head and trunk, droopy ears, snoring, and penis protrusion. Pulse rate, respiratory rate, and rectal temperature ranged between 30-45 beats/min, 4-12 breaths/min, and 35.6-37.2°C, respectively, at 30 min after xylazine injection, and there were no changes over time. Pulmonary function and acid-base balance were adequate (range partial pressures of arterial oxygen 73-123 mmHg and carbon dioxide 33-52 mmHg, arterial hemoglobin oxygen saturation 96-99%, pH 7.34-7.54, lactate 0.9-2.5 mmol/L). Yohimbine was administered 46-110 min after the injection of xylazine, and the first sign of recovery occurred within 1-4 min. Resedation after reversal with yohimbine was observed in two elephants. In conclusion, xylazine at the doses used induced light to deep sedation with stable physiology and most elephants remained standing.

AIM: To study the effect of yohimbine in the treatment of men with orgasmic dysfunction. METHODS: A 20-mg dose of yohimbine was first given to 29 men with orgasmic dysfunction of different aetiology in the clinic. Patients were then allowed to increase the dose at home (titration) under more favourable circumstances. The outcome and side effects were subsequently assessed. RESULTS: The patients were classified into three groups of orgasmic dysfunction: primary complete (13), primary incomplete (8) and secondary (8). Nocturnal emissions were present in 75%, 40% and 50% of patients in the above groups, respectively (overall average 62%). The men presented because of fertility problems (52%) or because they wanted to experience the pleasure of orgasm (48%). Of the 29 patients who completed the treatment, 16 managed to reach orgasm and were able to ejaculate either during masturbation or sexual intercourse. A further three achieved orgasm, but only with the additional stimulation of a vibrator. A history of preceding nocturnal emissions was present in 69% of the men in whom orgasm was induced but only 50% who failed treatment. Of the patients, two have subsequently fathered children (one set of twins) and another 3 men were also cured. Side effects were not sufficient to cause the men to cease treatment. CONCLUSION: Yohimbine is a useful treatment option in orgasmic dysfunction.

A large body of work has investigated the effect of various pharmacological compounds on aversive memory formation, retrieval, and modification in humans. A broad overview across signalling pathways and memory models is currently lacking. Here, we systematically review publications that tested the impact of acute pharmacological interventions on aversive memory in healthy humans, following PRISMA-2020. We identified 215 candidate compounds from 17 systems and searched PubMed, Web of Science and Scopus, until 14 June 2024. We identified 100 publications with 36 compounds targeting 13 systems. Three compounds were used by the majority of studies: hydrocortisone (n = 25), propranolol (n = 19), and D-cycloserine (n = 8), while many of the remaining 33 compounds were investigated in single studies only. We summarise the effect of each investigated compound across memory models, according to the targeted memory stage. Solid evidence emerges for an impact of propranolol on reconsolidation, and weak evidence for an impact of propranolol, 3,4-methylenedioxymethamphetamine (MDMA), benzodiazepines, yohimbine, reboxetine, and D-cycloserine on aversive memory encoding/consolidation, and valproic acid on extinction encoding/consolidation. Furthermore, 15 compounds showed significant effects in individual studies with no published replication attempts to date. We discuss potential research directions and suggest steps for greater comparability of findings between compounds, memory models, and laboratories.

OBJECTIVE: To determine the effectiveness and safety of pharmacological therapy in men older than 18 years with primary or secondary anorgasmia in terms of induced orgasm, improvement of the International Index of Erectile Function (IIEF), or Arizona Sexual Experience Scale (ASEX). METHODS: we conducted this systematic review according to the recommendations of the Cochrane Collaboration and following the PRISMA Statement. We designed a search strategy in MEDLINE (OVID), EMBASE, LILACS, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to the present. We assessed the risk of bias based on the STROBE statement for observational studies and the Rob 2.0 tool for clinical trials. RESULTS: 234 patients were included, and 232 were treated with pharmacological therapy in seven studies. Some pathologies reported were a history of prostatectomy, hypogonadism, psychiatric disorders, and use of antidepressants. Cabergoline was the most frequently administered treatment, followed by yohimbine and bupropion. The cabergoline improved orgasm in 66% of the population and yohimbine in 55%. The change in IIEF orgasmic function improved significantly with cabergoline and bupropion (P = <0.001 and P = 0.002). The ASEX improved with pycnogenol and was maintained in months 2,3 and 4 (p ≤ 0.05). The side effects reported were mild in three studies. Amantadine required discontinuation due to depression. CONCLUSION: Pharmacological therapy with cabergoline, yohimbine, bupropion, and pycnogenol can have a positive effect on the orgasmic function of patients with primary or secondary anorgasmia.

Erratum in Soc Cogn Affect Neurosci. 2026 Jan 21;21(1):nsag055. doi: 10.1093/scan/nsag055. The hypothalamus-pituitary-adrenal axis (HPA axis) and the sympathetic-adrenal-medullary system (SAM system), two neuroendocrine systems associated with the stress response, have often been implicated to modulate decision-making in various domains. This systematic review summarizes the scientific evidence on the effects of pharmacological HPA axis and SAM system modulation on decision-making. We found 6375 references, of which 17 studies fulfilled our inclusion criteria. We quantified the risk of bias in our results with respect to missing outcome data, measurements, and selection of the reported results. The included studies administered hydrocortisone, fludrocortisone (HPA axis stimulants), yohimbine, reboxetine (SAM system stimulants), and/or propranolol (SAM system inhibitor). Integrating the evidence, we found that SAM system stimulation had no impact on risk aversion, loss aversion or intertemporal choice, while SAM system inhibition showed a tentative reduction in sensitivity to losses. HPA axis stimulation had no effect on loss aversion or reward anticipation but likely a time-dependent effect on decision under risk. Lastly, combined stimulation of both systems exhibited inconsistent results that could be explained by dose differences (loss aversion) and sex differences (risk aversion). Future research should address time-, dose-, and sex-dependencies of pharmacological effects on decision-making. © The Author(s) 2024. Published by Oxford University Press.

Dietary supplements are widely used among athletes, and soccer players are no exception. Nevertheless, evidence supporting the use of dietary supplements aiming to enhance performance in soccer is somewhat contradictory, scarce, or even nonexistent. Thus, the present study aimed to systematically review and synthesize the effects of dietary supplements on athletic performance (e.g. distance covered, sprinting, jump performance) in elite soccer players. Studies enrolling highly trained, elite, and world-class soccer players using dietary supplements were searched in MEDLINE/PubMed, Web of Science, Scopus, and EBSCO databases in June 2022. In total, 1043 studies were identified, and 18 met the eligibility criteria. The studies evaluated the impacts on athletic performance of several dietary supplements, including caffeine, creatine, protein, beverages with carbohydrates and electrolytes, tart cherry juice, nitrate-rich beetroot juice, sodium bicarbonate with minerals, yohimbine, and a proprietary nutraceutical blend. Caffeine supplementation in doses between 3 and 6 mg/kg of body mass may improve jump height and sprint ability, particularly in female players, but individual response to caffeine must be considered. Creatine may improve sprint, agility, and in female players, jump performance. Protein supplementation can improve sprint and jump performance between matches, especially if protein ingested from food is not up to recommendations. Beverages containing carbohydrates and electrolytes can be used as part of the strategies to achieve carbohydrate intake during training and match-days but used alone do not benefit athletic performance. Tart cherry juice might be useful for maintaining athletic performance after matches that produce higher force loss and exercise-induced muscle damage, although polyphenols from the diet might attenuate the effects of tart cherry supplementation. Nitrate-rich beetroot concentrate can attenuate performance decrease in the days following matches. Further investigation with sodium bicarbonate alone is necessary, as supplementation protocols with elite players included other substances. Finally, the available data does not support

Alcohol use disorder (AUD) is a significant public health concern, contributing to a myriad of social, psychological, and physiological issues. Despite substantial efforts within the alcohol research field, promising preclinical findings have failed to translate to clinical use, highlighting the necessity to develop safe and effective pharmacological probes with the ability to be used in preclinical and clinical research. Yohimbine, an α2 adrenergic receptor antagonist, is a well-validated pharmacological tool that has been widely employed in alcohol studies to evaluate noradrenergic activation. This scoping systematic review examines published literature in rodent and human studies involving the use of yohimbine relevant to alcohol research. We conducted a systematic literature review of MEDLINE, Embase, Web of Science Core Collection, CINAHL, PsycInfo, and Cochrane Central Register of Controlled Trials to identify: (1) Experimental Characteristics and Methodology, (2) Sex Differences, (3) Neurochemical Systems and Brain Regions, and (4) Discussion of Applications for Medication Development. Sixty-seven (62 preclinical and 5 clinical) studies were identified meeting the stated criteria, comprising extensive evidence supporting the use of yohimbine as a safe, titratable pharmacological agent for translational alcohol research. Support for the use of yohimbine as a fully translational tool, however, is hindered by limited available findings from human laboratory studies, as well as a dearth of studies examining sex differences in yohimbine's mechanistic actions. Additional consideration should be given to further translational modeling, ideally allowing for parallel preclinical and clinical assessment of yohimbine, methodological assessment of neurochemical systems and brain regions. © 2022. The Author(s), under exclusive licence to American College of Neuropsychopharmacology.

BACKGROUND: Psychotherapy and pharmacotherapy are first-line treatments for mental disorders. Despite recent improvements, only approximately 50% of the patients reach sustained remission, indicating a need for novel developments. The main concept put forward in this systematic review and hypothesis article is the targeted co-administration of defined neurobiological interventions and specific psychotherapeutic techniques. METHODS: We conducted a systematic literature search for randomized controlled trials comparing the efficacy of augmented psychotherapy to psychotherapy alone. RESULTS: Thirty-five trials fulfilled the inclusion criteria. The majority (29 trials) used augmentation strategies such as D-cycloserine, yohimbine, or sleep to enhance the effects of exposure therapy for anxiety disorders. Fewer studies investigated noninvasive brain stimulation with the aim of improving cognitive control, psychedelic compounds with the aim of enhancing existentially oriented psychotherapy, and oxytocin to improve social communication during psychotherapy. Results demonstrate small augmentation effects for the enhancement of exposure therapy - however, some of the studies found negative results. Other methods are less thoroughly researched, and results are mixed. CONCLUSIONS: This approach provides an open matrix for further research and has the potential to systematically guide future studies. © 2021 S. Karger AG, Basel.

The objective was to study available evidence for ingredients of popular over-the-counter testosterone and erectile dysfunction (ED) supplements. The top 16 male testosterone and 16 ED supplements in the USA were identified from the most popular online retailers: A1 Supplements, Amazon, Vitamin Shoppe, and Walmart. In total, 37 ingredients were identified and PUBMED online database was reviewed for randomized-controlled trials (RCT) studying their efficacy. Ingredients were categorized based on evidence quantity using an adapted version of the American Heart Association scoring system. In total, 16 ingredients from testosterone supplements and 21 from ED supplements were identified. Tribulus, Eurycoma longifolia, Zinc, L-arginine, Aspartate, Horny goat weed, and Yohimbine were most common. In all, 105 RCTs studying the identified ingredients were found. No whole supplement products have published RCT evidence. 19% of ingredients received an A grade for strong positive evidence with net positive evidence in two or more RCTs. In total, 68% received C or D grades for contradicting, negative, or lacking evidence. Overall, 69% of ingredients in testosterone supplements and 52% of ingredients in ED supplements have published RCT evidence. Many male supplements claim to improve testosterone or ED parameters; however, there is limited evidence, which should be considered when counseling patients.