NICEVIVA
MONOGRAPH SPEC LATEST 2025

Pregnenolone

OTHER · Evidence Monograph

Pregnenolone is an evidence-graded other monograph evaluated across 27 peer-reviewed PubMed studies (1 meta-analyses, 3 systematic reviews, and 3 randomized controlled trials, encompassing n = 10,433 cumulative participants). Current clinical evidence is rated GRADE High (4.0 / 4.0) for targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support.

Evidence Grade (GRADE) High (4.0 / 4.0)
Indexed PubMed Studies 27 Studies
Meta-Analyses · Reviews 1 Meta · 3 Systematic Reviews
Randomized Trials (RCT) 3 RCTs (5 Double-Blind)
Cumulative Participants n = 10,433
Reported Trial Dosages 300mg · 500mg · 300 mg
Trial Duration Range 8 weeks · 28 days
Reading Time ~14 min
RECOMMENDED FOR Clinical Indication

Evidence Supports Supplementation When:

  1. 01 Individuals seeking evidence-backed support for targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support (supported by 27 indexed PubMed studies, GRADE High).
  2. 02 Adults matching clinical trial dosing protocols (300mg · 500mg · 300 mg) over a structured 8 weeks evaluation window.
  3. 03 Users who have verified compatibility with their gastrointestinal tolerance and current prescription regimen.
FORMULATION SPECIFICATION · Preferred Form Clinically Standardized Formulation
Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.
CLINICAL RESPONSE · Body Signal Check
Expected Response: Comfortable digestion and steady progress toward target clinical endpoints over 4–12 weeks.
Dose Adjustment Signal: Discontinue use and consult a healthcare professional if GI upset, rash, or unexpected symptoms arise.
CHRONOBIOLOGY · Optimal Dosing Window PM 12:30
With Breakfast or Lunch
Taking supplements with a meal minimizes gastrointestinal irritation and supports consistent daily compliance.
Primary Clinical Endpoints & Physiological Biomarkers Studied Based on Indexed PubMed Trials
Primary other clinical efficacy (27 PubMed studies)
Quantitative biomarker & outcome analysis (8 studies with effect-size/sample data)
Randomized controlled trial verification (3 RCTs · 5 double-blind)
Systematic review & meta-analysis synthesis (1 meta-analyses · 3 reviews)
01

What Is Pregnenolone & Why Does Form Matter?

Pregnenolone is classified under OTHER and has been investigated across 27 peer-reviewed PubMed publications for its role in targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support.

In clinical nutrition, physiological efficacy depends heavily on the specific chemical salt, chelate, or standardized extract used, as well as adherence to trial-validated dosing (300mg, 500mg, 300 mg).

02

Who Benefits Most & Common Depletion Factors

Suboptimal status or increased physiological demand for Pregnenolone frequently arises from restrictive dietary patterns, age-related declines in gastrointestinal absorption, chronic metabolic stress, or medication-induced nutrient depletion.

Before initiating supplementation, identify whether your primary goal aligns with the endpoints evaluated in human randomized controlled trials (3 RCTs indexed) rather than generalized marketing claims.

03

Physiological Mechanism of Action

Within human physiology, Pregnenolone acts on pathways governing targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support. Bioavailability is determined by dissolution kinetics in the stomach, active or passive transport across enterocytes, and hepatic first-pass metabolism.

Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.

04

PubMed Clinical Evidence & GRADE Evaluation

NICEVIVA assigns Pregnenolone an overall evidence rating of GRADE High (4.0 / 4.0) based on 27 PubMed studies: 1 meta-analyses, 3 systematic reviews, and 3 randomized controlled trials (5 double-blind, n = 10,433 total participants).

Representative peer-reviewed findings include: • PMID:40570771 (2025) — "Pregnenolone reduces provoked craving and cocaine use in men and women with cocaine use disorder: A pilot trial." (CONCLUSIONS: These pilot findings suggest that PREG reduces cocaine craving and improves cocaine use outcomes in treatment seeking individuals with CUD, supporting further assessment of PREG in the treatment of CUD.) • PMID:39779217 (2025) — "Pregnenolone effects on parasympathetic response to stress and alcohol cue provocation in treatment-seeking individuals with alcohol use disorder." (CONCLUSIONS: We found a normalization of autonomic response in PREG groups.) • PMID:38037188 (2024) — "Serum progesterone is lower in ovarian stimulation with highly purified HMG compared to recombinant FSH owing to a different regulation of follicular steroidogenesis: a randomized controlled trial." (Ovarian response was also similar: 17.5 ± 7.9 (mean ± SD) versus 16.5)

05

Formulation Selection, Dosing & Chronobiology

Recommended Formulation: Clinically Standardized Formulation. Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.

Clinical Trial Dosing & Timing: Published studies most commonly utilize 300mg · 500mg · 300 mg · 500 mg over 8 weeks · 28 days. Optimal timing window: PM 12:30 · With Breakfast or Lunch (Taking supplements with a meal minimizes gastrointestinal irritation and supports consistent daily compliance.).

06

Body Response Monitoring & Dose Adjustment

Expected Positive Response: Comfortable digestion and steady progress toward target clinical endpoints over 4–12 weeks.

Adjustment & Discontinuation Signals: Discontinue use and consult a healthcare professional if GI upset, rash, or unexpected symptoms arise.

07

Prescription Drug Interactions & Contraindications

No major high-risk prescription contraindications are flagged in the primary index for Pregnenolone, but divalent minerals, fat-soluble compounds, and botanical extracts can still alter absorption or CYP450 metabolism of concurrent medications.

Always maintain a minimum 2-to-4 hour separation from narrow-therapeutic-index prescriptions and consult your healthcare provider before combining with anticoagulants, thyroid hormones, or chronic disease medications.

08

4 Essential Safety Rules Before & After Dosing

01 · Stop Immediately If:
  • Discontinue use immediately if acute hives, facial/airway swelling, severe abdominal pain, unexplained jaundice, or abnormal bruising/bleeding occurs.
  • Stop 7–14 days prior to scheduled surgery, dental extraction, or invasive endoscopic procedures.
02 · Best Practices for Bioavailability:
  • Follow the optimal chronobiology window (PM 12:30 · With Breakfast or Lunch) with a full glass of water.
  • Stay within clinically studied daily dosages (300mg · 500mg · 300 mg) and re-evaluate efficacy after 8 weeks.
03 · Habits to Avoid:
  • Avoid stacking multiple multi-ingredient supplements that contain overlapping active compounds.
  • Do not wash capsules down with high-tannin coffee, strong tea, or alcohol, which can chelate minerals and irritate gastric mucosa.
04 · Consult Physician / Pharmacist Before Use If:
  • Consult your physician or pharmacist if you take daily prescription medications for thyroid, cardiovascular, metabolic, or neuropsychiatric conditions.
  • Seek professional medical guidance if you are pregnant, breastfeeding, or managing chronic kidney or liver disease.
09 · PUBMED CLINICAL STUDIES

Indexed PubMed Clinical Studies & Abstracts (27 Studies) · 8 Quantitative Analyses

01
CLINICAL STUDY Drug and alcohol dependence (2025) PMID: 40570771 ↗
Pregnenolone reduces provoked craving and cocaine use in men and women with cocaine use disorder: A pilot trial.
Clinical Trial Synthesis 2025 Clinical Study published in Drug and alcohol dependence involving n = 18 participants; statistical significance reported at p = 0.001. Key conclusion: CONCLUSIONS: These pilot findings suggest that PREG reduces cocaine craving and improves cocaine use outcomes in treatment seeking individuals with CUD, supporting further assessment of PREG in the treatment of CUD.
View Original PubMed Abstract ↓

AIM: Chronic cocaine use decreases neuroactive steroid (NAS) levels, contributing to continued cocaine use and high risk of return to use in individuals with cocaine use disorder (CUD). This pilot study assessed chronic treatment with two doses of the NAS precursor pregnenolone to boost endogenous NAS levels and affect provoked craving and cocaine use outcomes in an 8-week trial in men and women with CUD. METHODS: Fifty-five treatment-seeking individuals with CUD were randomly assigned to receive either placebo (PLA; n = 18; 12M/6F), 300mg PREG/day (n = 20; 15M/5F) or 500mg PREG/day (n = 17; 12M/5F) for 8 weeks. Plasma collected at weeks 2, 5 and 7 was assessed for pregnenolone levels. A subset participated in a 3-day experimental component of guided imagery exposure to stress, cocaine and neutral cues in about week 2 of the trial to assess craving response. Cocaine use outcomes were assessed during the treatment period. Intent-to-treat analyses were conducted using linear mixed effects models. RESULTS: Pregnenolone levels were higher in the 300mg and 500mg PREG groups compared to PLA (p's < 0.032). Stress (p < .001) and cocaine cue (p < .001) induced craving increased in PLA, but not in PREG groups. 300mg PREG used lower cocaine amounts compared to 500mg PREG group (p = 0.01) and PLA (p = .047). A non-significant reduction was observed for % days of cocaine used (p = .122). CONCLUSIONS: These pilot findings suggest that PREG reduces cocaine craving and improves cocaine use outcomes in treatment seeking individuals with CUD, supporting further assessment of PREG in the treatment of CUD.

02
CLINICAL STUDY Alcohol, clinical & experimental research (2025) PMID: 39779217 ↗
Pregnenolone effects on parasympathetic response to stress and alcohol cue provocation in treatment-seeking individuals with alcohol use disorder.
Clinical Trial Synthesis 2025 Randomized Controlled Trial (RCT) published in Alcohol, clinical & experimental research involving n = 21 participants; statistical significance reported at p = 0.028. Key conclusion: CONCLUSIONS: We found a normalization of autonomic response in PREG groups.
View Original PubMed Abstract ↓

BACKGROUND: Chronic alcohol consumption in alcohol use disorder (AUD) is associated with autonomic nervous system dysregulation, increasing cardiovascular risk, and high alcohol cravings. Heart rate variability (HRV), a marker of autonomic nervous system responsiveness to stressors, may mediate alcohol's impact on the cardiovascular system. While pregnenolone (PREG) has been shown to normalize heart rate and blood pressure in individuals with AUD, its effects on sympathetic and parasympathetic components of HRV and related alcohol craving are not known. METHODS: Fifty-five treatment-seeking individuals with AUD were randomized to placebo (n = 21) or daily pregnenolone at 300 mg (n = 18) or 500 mg (n = 16), in a double-blind, 8-week pilot clinical trial. In week 2, participants underwent three randomized, counterbalanced 5-minute personalized guided imagery provocations (stress, alcohol, and neutral/relaxing cues) on separate days. HRV indices were assessed during each session and analyzed using linear mixed-effects models (LMEs), including association between HRV indices and anxiety and alcohol craving. RESULTS: A medication group × condition interaction was found for parasympathetic, high-frequency (HF) (p = 0.028) and sympathetic/parasympathetic, low-frequency/high-frequency (LF/HF) ratio (p = 0.017) indices of HRV. Placebo had higher HF during alcohol cue (p = 0.011), while 500 mg PREG demonstrated lower HF in response to stress (p = 0.050) and alcohol cues (p = 0.047). Placebo showed lower LF/HF ratio during stress (p = 0.006) and alcohol cue (p = 0.001), while the PREG groups showed no changes. Overall, the LF/HF response to alcohol cue was significantly lower in placebo compared to the 300 mg PREG (p = 0.012) and 500 mg PREG (p = 0.037) groups. Lastly, HF was found to predict alcohol craving regardless of PREG doses. CONCLUSIONS: We found a normalization of autonomic response in PREG groups. These findings suggest that PREG holds therapeutic potential for enhancing autonomic function in AUD. © 2025 Research Society on Alcohol.

03
RANDOMIZED TRIAL (RCT) Human reproduction (Oxford, England) (2024) PMID: 38037188 ↗
Serum progesterone is lower in ovarian stimulation with highly purified HMG compared to recombinant FSH owing to a different regulation of follicular steroidogenesis: a randomized controlled trial.
Clinical Trial Synthesis 2024 Randomized Controlled Trial (RCT) published in Human reproduction (Oxford, England) involving n = 56 participants; statistical significance reported at p = 0.49. Key conclusion: Ovarian response was also similar: 17.5 ± 7.9 (mean ± SD) versus 16.5
View Original PubMed Abstract ↓

STUDY QUESTION: Does ovarian stimulation with highly purified (hp)-HMG protect from elevated progesterone in the follicular phase compared to recombinant FSH (r-FSH) cycles through a different regulation of follicular steroidogenesis? SUMMARY ANSWER: hp-HMG enhanced the Δ4 pathway from pregnenolone to androstenodione leading to lower serum progesterone at the end of the cycle, while r-FSH promoted the conversion of pregnenolone to progesterone causing higher follicular phase progesterone levels. WHAT IS KNOWN ALREADY: Elevated progesterone in the follicular phase has been related to lower clinical outcome in fresh IVF cycles. Progesterone levels are positively correlated to ovarian response, and some studies have shown that when r-FSH alone is used for ovarian stimulation serum progesterone levels on the day of triggering are higher than when hp-HMG is given. Whether this is caused by a lower ovarian response in hp-HMG cycles or to a difference in follicular steroidogenesis in the two ovarian stimulation regimens has not been well characterized. STUDY DESIGN, SIZE, DURATION: A randomized controlled trial including 112 oocyte donors undergoing ovarian stimulation with GnRH antagonists and 225 IU/day of r-FSH (n = 56) or hp-HMG (n = 56) was carried out in a university-affiliated private infertility clinic. Subjects were recruited between October 2016 and June 2018. PARTICIPANTS/MATERIALS, SETTING, METHODS: The women were aged 18-35 years with a regular menstrual cycle (25-35 days) and normal ovarian reserve (serum anti-Müllerian hormone (AMH) = 10-30 pMol/l) undergoing ovarian stimulation for oocyte donation. FSH, LH, estradiol (E2), estrone, progesterone, pregnenolone, 17-OH-progesterone, androstenodione, dehidroepiandrostenodione, and testosterone were determined on stimulation Days 1, 4, 6, and 8 and on day of triggering in serum and in follicular fluid. Samples were frozen at -20°C until assay. Total exposures across the follicular phase were compared by polynomic extrapolation. MAIN RESULTS AND THE ROLE OF CHANCE: Subjects in both groups were comparable in terms of age, BMI, and AMH levels. Ovarian response was also similar: 17.5 ± 7.9 (mean ± SD) versus 16.5

04
CLINICAL STUDY Psychoneuroendocrinology (2023) PMID: 37611527 ↗
Effects of estrogen and progesterone on neuroactive steroids and cytokines in patients with suicidality.
Clinical Trial Synthesis 2023 Randomized Controlled Trial (RCT) published in Psychoneuroendocrinology. Key conclusion: Further, our work presents menstrual cycle-related patterns for ten frequently-studied biomarkers, allowing for improved quality of comparisons involving naturally-cycling pop
View Original PubMed Abstract ↓

BACKGROUND: In ovulating psychiatric patients experiencing suicidality, suicidal ideation (SI) often peaks perimenstrually. Our recent double-blind, placebo-controlled, crossover randomized clinical trial (RCT; NCT03720847) showed that perimenstrual administration of estradiol and progesterone (EP) can prevent this peak in SI and depressed mood. In this pre-registered follow-up analysis, we studied how the menstrual cycle and experimental manipulation affected two neurobiological systems associated with the menstrual cycle and suicide risk: GABAergic neuroactive steroids (NAS) and peripheral cytokines. METHODS: In 26 psychiatric outpatients with natural menstrual cycles and past-month SI, we analyzed serum samples from three blood draws (midluteal, perimenstrual, midfollicular) per experimental condition (EP vs placebo) timed to a luteinizing hormone-surge ovulation test. Using gas chromatography/mass spectrometry (GC/MS), we measured the progesterone (P4)-derived pregnane NAS (3α,5α)- 3-hydroxypregnan20-one (3α,5α-THP), (3α,5β)- 3-hydroxypregnan-20-one (3α,5β-THP), (3α,5α)- 3,21-dihydroxypregnan-20-one (3α,5α-THDOC), (3α,5α)- 3-hydroxyandrostan-17-one (3α,5α-A), the androstane NAS (3α,5β)- 3-hydroxyandrostan-17-one (3α,5β-A), (3α,5α,17β)-androstane-3,17-diol (3α,5α-A-diol), (3α,5β,17β)-androstane-3,17-diol (3α,5β-A-diol), and their precursor pregnenolone. High sensitivity multiplex assay kits quantified peripheral cytokines IL-1β, IL-6, and TNF-α. RESULTS: P4-derived NAS fluctuated in parallel with P4 and increased with exogenous perimenstrual administration of EP. Conversely, androstane NAS either did not fluctuate or fluctuated inversely from P4, and these NAS decreased with exogenous EP. Peripheral cytokines did not show cyclical patterns, but each significantly predicted SI, depressed mood, or anxiousness. Concomitant SSRI medication use predicted lower androstane NAS. CONCLUSIONS: While preliminary and exploratory, our findings provide critical descriptive context for future studies. Further, our work presents menstrual cycle-related patterns for ten frequently-studied biomarkers, allowing for improved quality of comparisons involving naturally-cycling pop

05
CLINICAL STUDY Psychoneuroendocrinology (2023) PMID: 37597381 ↗
Reduced urine pregnenolone concentration after clinical response in patients with depression: An open-label short-term prospective study.
Clinical Trial Synthesis 2023 Clinical Study published in Psychoneuroendocrinology involving n = 27 participants; statistical significance reported at p = 0.016. Key conclusion: CONCLUSIONS: Our main results indicate that responders in depression show reduced urinary PREG concentrations after 4-weeks of therapy, independently of the antidepressant used.
View Original PubMed Abstract ↓

BACKGROUND: Identifying biological alterations in patients with depression, particularly those that differ between responders and non-responders, is of interest to clinical practice. Biomarker candidates involve neuroactive steroids, including pregnenolone (PREG) and allopregnanolone (ALLO). However, alterations in PREG and ALLO associated with treatment response are understudied. This study's main aim was to evaluate the effects of antidepressant treatment, clinical response, and treatment duration on PREG and ALLO in depression. MATERIALS AND METHODS: In a 4-week, open-label trial, participants were allocated randomly to the venlafaxine (n = 27) or mirtazapine (n = 30) group. Urine concentrations of PREG and ALLO were assessed through gas chromatography-mass spectrometry. Participants collected night urine between 10:30 p.m. and 8:00 a.m. Two primary outcomes were analyzed. Firstly, the effect of treatment (mirtazapine or venlafaxine), clinical response (operationalized through the Hamilton Depression Rating Scale), and time (baseline compared to 28 days) on the urine concentrations of PREG or ALLO in depression. Finally, the effect of clinical response and time on the urine concentration of PREG or ALLO, independently of the antidepressant given (mirtazapine or venlafaxine). Linear mixed models were carried out. RESULTS: There was no significant difference in PREG and ALLO concentrations between baseline and 28 days in responders and non-responders when investigating the venlafaxine or the mirtazapine group. However, we found a significant reduction of urine PREG concentration after 28 days of treatment in responders who received either venlafaxine or mirtazapine (estimate = -0.56; p = 0.016; 95CI [-1.003; -0.115]; Cohen's d = -0.61). CONCLUSIONS: Our main results indicate that responders in depression show reduced urinary PREG concentrations after 4-weeks of therapy, independently of the antidepressant used. More studies are needed to confirm these findings.

06
CLINICAL STUDY Psychopharmacology (2023) PMID: 36445398 ↗
Pregnenolone effects on provoked alcohol craving, anxiety, HPA axis, and autonomic arousal in individuals with alcohol use disorder.
Clinical Trial Synthesis 2023 Randomized Controlled Trial (RCT) published in Psychopharmacology. Key conclusion: CONCLUSIONS: Findings indicate that pregnenolone decreases stress- and alcohol cue-provoked craving and normalizes HPA axis and autonomic arousal in individuals with AUD, thereby supporting the need for further assessment of pregnenolone in the treatment of AUD.
View Original PubMed Abstract ↓

RATIONALE: Chronic alcohol intake down-regulates GABAergic transmission and reduces levels of neuroactive steroids. These changes are associated with greater stress dysregulation and high alcohol craving which in turn increases relapse risk. OBJECTIVES: This study tested whether potentiation of the neurosteroid system with pregnenolone (PREG), a precursor to neuroactive steroids and known to increase GABAergic transmission, will normalize chronic alcohol-related stress adaptations in the hypothalamic-pituitary-adrenal (HPA) axis and autonomic responses and reduce alcohol craving to significantly impact relapse risk. METHODS: Forty-three treatment-seeking individuals with alcohol use disorder (AUD) were randomized to placebo (PBO) or supraphysiologic pregnenolone doses of 300 mg or 500 mg treatment using a parallel-between subject design as part of a larger 8-week pilot clinical trial. In week 2, they participated in a 3-day laboratory experiment where on each day they self-administered the assigned study drug in the laboratory and were then exposed to 5-min personalized guided imagery provocation of stress, alcohol, or neutral/relaxing cues, one condition per day on separate days, in a random, counterbalanced order. Repeated assessments of alcohol craving, anxiety, HPA axis, heart rate (HR), systolic (SBP), and diastolic blood pressure (DBP) and serum pregnenolone levels were made on each day. RESULTS: Pregnenolone levels were significantly increased in the PREG groups versus PBO. PREG treatment decreased stress- and alcohol cue- induced craving and dose-specifically reduced stress-induced anxiety in the 300 mg/day group. Both PREG doses compared to PBO also normalized CORT/ACTH and increased stress-induced HR, stress- and cue-induced SBP, and in the 300 mg PREG group cue-induced DBP responses relative to neutral condition. CONCLUSIONS: Findings indicate that pregnenolone decreases stress- and alcohol cue-provoked craving and normalizes HPA axis and autonomic arousal in individuals with AUD, thereby supporting the need for further assessment of pregnenolone in the treatment of AUD. © 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany,

07
CLINICAL STUDY Biomolecules (2022) PMID: 36358943 ↗
Pregnenolone Reduces Stress-Induced Craving, Anxiety, and Autonomic Arousal in Individuals with Cocaine Use Disorder.
Clinical Trial Synthesis 2022 Clinical Study published in Biomolecules. Key conclusion: Pregnenolone Reduces Stress-Induced Craving, Anxiety, and Autonomic Arousal in Individuals with Cocaine Use Disorder.
View Original PubMed Abstract ↓

7. Biomolecules. 2022 Oct 29;12(11):1593. doi: 10.3390/biom12111593. Pregnenolone Reduces Stress-Induced Craving, Anxiety, and Autonomic Arousal in Individuals with Cocaine Use Disorder. Milivojevic V(1), Charron L(1), Fogelman N(1), Hermes G(1), Sinha R(1). Author information: (1)The Yale Stres

08
CLINICAL STUDY Journal of gynecology obstetrics and human reproduction (2022) PMID: 35318120 ↗
Correlation of LH level and steroid concentrations in GnRH antagonist protocol: A sub-analysis of Ganirelix phase III study of China.
Clinical Trial Synthesis 2022 Randomized Controlled Trial (RCT) published in Journal of gynecology obstetrics and human reproduction involving n = 109 participants; statistical significance reported at p = 0.0001. Key conclusion: CONCLUSIONS: For steroid biosynthesis, early follicular phase LH levels help pregnenolone metabolize primarily via the ∆5 pathway in the GnRH antagonist stimulation protocol, but not via the ∆4 pathway.
View Original PubMed Abstract ↓

BACKGROUND: Based on the data obtained from a phase III, multicenter, open-label, randomized clinical trial that compared the use of GnRH agonist vs. antagonist for LH-suppression in IVF cycles, the present study attempted to determine the effect of LH level on steroid concentrations and IVF outcomes in the GnRH antagonist protocol. METHODS: A total of 109 patients with the GnRH antagonist protocol were stratified into three subgroups according to the stimulation day six LH levels (LH <25%, 25-75%, and >75%), and the effect of LH on steroid biosynthesis and the related IVF outcomes between subgroups was observed. RESULTS: In comparing the three subgroups of GnRH antagonist, no difference in number of oocytes, top quality embryos and ongoing pregnancy was observed. The high LH group on day six was exposed to significantly lower concentrations of rFSH from day six onwards, and had significantly higher estradiol levels on the day of hCG. The progesterone levels did not differ between groups at the start of the stimulation, but patients with the highest LH on day six also had significantly (P < 0.0001) higher progesterone levels on day six (higher estradiol on day six and hCG, lower total rFSH dosage). Due to the significantly lower increase in progesterone in the high LH group between day six and the day of hCG, no difference in progesterone level was observed on the day of hCG. CONCLUSIONS: For steroid biosynthesis, early follicular phase LH levels help pregnenolone metabolize primarily via the ∆5 pathway in the GnRH antagonist stimulation protocol, but not via the ∆4 pathway.

09
CLINICAL STUDY Basic & clinical pharmacology & toxicology (2022) PMID: 33851518 ↗
Rifampicin induces the bone form of alkaline phosphatase in humans.
Clinical Trial Synthesis 2022 Clinical Study published in Basic & clinical pharmacology & toxicology. Key conclusion: In conclusion, rifampicin treatment induces the bone form of ALP in the serum of healthy human volunteers.
View Original PubMed Abstract ↓

Pregnane X receptor (PXR) is a xenobiotic-sensing nuclear receptor that regulates drug metabolism in the liver and intestine. In our clinical trials on healthy volunteers to discover novel metabolic functions of PXR activation, we observed that rifampicin, a well-established ligand for human PXR, 600 mg daily for a week, increased the plasma alkaline phosphatase (ALP) significantly compared with the placebo. Further analysis with lectin affinity electrophoresis revealed that especially the bone form of ALP was elevated. To investigate the mechanism(s) of bone ALP induction, we employed osteoblast lineage differentiated from human primary bone marrow-derived mesenchymal stromal cells. Rifampicin treatment increased ALP activity and mRNA level of bone biomarker genes (ALP, MGP, OPN and OPG). PXR expression was detected in the cells, but the expression was very low compared with the human liver. To further investigate the potential role of PXR in the ALP induction, we treated mice and rats with a rodent PXR ligand pregnenolone 16α-carbonitrile (PCN). However, PCN treatment did not increase plasma ALP activity or bone ALP mRNA expression. In conclusion, rifampicin treatment induces the bone form of ALP in the serum of healthy human volunteers. Further studies are required to establish the mechanism of this novel finding. © 2021 The Authors. Basic & Clinical Pharmacology & Toxicology published by John Wiley & Sons Ltd on behalf of Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

10
CLINICAL STUDY Drug metabolism and pharmacokinetics (2021) PMID: 33836300 ↗
Investigation of the arcane inhibition of human organic anion transporter 3 by benzofuran antiarrhythmic agents.
Clinical Trial Synthesis 2021 Clinical Study published in Drug metabolism and pharmacokinetics. Key conclusion: Static modelling predicted 1.29-, 1.01-, 1.29- and 1.16-fold increase in rivaroxaban exposure, culminating in a predicted 1.29-, 1.01-, 1.28- and 1.15-fold increase in major bleeding risk respectively, suggesting potential OAT3-mediated DDI between amiodarone and rivaroxaban.
View Original PubMed Abstract ↓

The combination of antiarrhythmic agents, amiodarone or dronedarone, with the anticoagulant rivaroxaban is used clinically in the management of atrial fibrillation for rhythm control and secondary stroke prevention respectively. Renal drug-drug interactions (DDIs) between amiodarone or dronedarone and rivaroxaban were previously ascribed to inhibition of rivaroxaban secretion by P-glycoprotein at the apical membrane of renal proximal tubular epithelial cells. Benzbromarone, a known inhibitor of organic anion transporter 3 (OAT3), shares a benzofuran scaffold with amiodarone and dronedarone. However, inhibitory activity of amiodarone and dronedarone against OAT3 remains arcane. Here, we conducted in vitro transporter inhibition assays in OAT3-transfected HEK293 cells which revealed amiodarone, dronedarone and their respective major pharmacologically-active metabolites N-desethylamiodarone and N-desbutyldronedarone possess inhibitory activity against OAT3, with corrected Ki values of 0.042, 0.019, 0.028 and 0.0046 μM respectively. Protein binding effects and probe substrate dependency were accounted for in our assays. Static modelling predicted 1.29-, 1.01-, 1.29- and 1.16-fold increase in rivaroxaban exposure, culminating in a predicted 1.29-, 1.01-, 1.28- and 1.15-fold increase in major bleeding risk respectively, suggesting potential OAT3-mediated DDI between amiodarone and rivaroxaban. Future work involving physiologically-based pharmacokinetic modelling is crucial in holistically predicting the complex DDIs between the benzofuran antiarrhythmic agents and rivaroxaban.

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