The effect of St. John's wort on the pharmacokinetics, metabolism and biliary excretion of finasteride and its metabolites in healthy men

Pharmacokinetic and pharmacodynamic herb-drug interactions-part I. Herbal medicines of the central nervous system

Unlike conventional drug substances, herbal medicines are composed of a complex of biologically active compounds. Therefore, the potential occurrence of herb-drug interactions is even more probable than for drug-drug interactions. Interactions can occur on both the pharmacokinetic and pharmacodynamic level. Herbal medicines may affect the resulting efficacy of the concomitantly used (synthetic) drugs, mainly on the pharmacokinetic level, by changing their absorption, distribution, metabolism, and excretion. Studies on the pharmacodynamic interactions of herbal medicines and conventional drugs are still very limited. This interaction level is related to the mechanism of action of different plant constituents. Herb-drug interactions can cause changes in drug levels and activities and lead to therapeutic failure and/or side effects (sometimes toxicities, even fatal). This review aims to provide a summary of recent information on the potential drug interactions involving commonly used herbal medicines that affect the central nervous system (Camellia, Valeriana, Ginkgo, Hypericum, Humulus, Cannabis) and conventional drugs. The survey databases were used to identify primary scientific publications, case reports, and secondary databases on interactions were used later on as well. Search keywords were based on plant names (botanical genera), officinal herbal drugs, herbal drug preparations, herbal drug extracts.

Chronic supplementation of a multi-ingredient herbal supplement increases speed of cognitive task performance alongside changes in the urinary metabolism of dopamine and the gut microbiome in cognitively intact older adults experiencing subjective memory decline: a randomized, placebo controlled, parallel groups investigation

Background

The effects of herbs on brain function are often investigated in isolation, yet herbal preparations are often complex combinations of phytochemicals, designed to target widespread mechanisms.

Objective

To assess the effects of chronic, 12 weeks, supplementation of a multi-ingredient herbal supplement (containing Bacopa monnieri, Gotu kola leaf, Turmeric whole powder, Reishi full spectrum, Rosemary, Cardamom, Holy Basil, Turmeric Wholistic™ extract, Green Tea & Seagreens) on cognitive function in older adults with subjective memory decline. Secondly, to investigate whether effects are underpinned by shifts in microbial composition and/or metabolism of the herbs.

Methods

Male and female participants (N = 128) aged between 55-75 years completed lab-based cognitive assessments, and provided stool and urine samples, at baseline and then following 90 days of multi-ingredient herb, or placebo, supplementation.

Results

Deficits in memory were observed in response to 90 days of multi-ingredient herbal supplement supplementation but the positive effects were all focused on speed of cognitive task performance, with an additional improvement in the false alarm rate on the rapid visual information processing task. These improvements coincided with an increased presence of tyrosine in the urinary metabolome and this may implicate the role of dopamine in these processing and/or motor speed increases. Finally, multi-ingredient herbal supplementation significantly reduced levels of 3 bacterial species in the gut microbiome and one of these, Sutterella, coincides with lower levels of constipation reported in the multi-ingredient herbal supplement condition.

Conclusion

A multi-ingredient herbal supplement increases speed of cognitive task performance and increased metabolism of tyrosine suggests that this is modulated by increased dopaminergic activity. Reduced levels of Sutterella in the gut is associated with improved bowel movements of participants. Interpretation of the negative effects on memory are, however, stymied by an unequal randomization of participants into treatment groups pre- and post-COVID 19.Clinical trial registration: identifier NCT05504668.

Topical Delivery of Atraric Acid Derived from Stereocaulon japonicum with Enhanced Skin Permeation and Hair Regrowth Activity for Androgenic Alopecia

Atraric acid (AA) is a phenolic compound isolated from Stereocaulon japonicum that has demonstrated anti-androgen properties and was used to design an alternative formulation for the treatment of alopecia. This new topical formulation was designed using a solvent mixture system composed of ethanol as a volatile vehicle, oleic acid as a permeation enhancer, and water for skin hydration. The ideal topical AA formulation (AA-TF#15) exhibited an 8.77-fold higher human skin flux and a 570% increase in dermal drug deposition, compared to 1% (w/w) AA in ethanol. In addition, compared to other formulations, AA-TF#15 (1% [w/w] AA) activated keratinocytes and human dermal papilla cell proliferation at a concentration of 50 µM AA, which is equivalent to 50 µM minoxidil. Moreover, AA-TF#15 treatment produced a significant increase in hair regrowth by 58.0% and 41.9% compared to the 1% (w/w) minoxidil and oral finasteride (1 mg/kg)-treated mice. In addition, AA-TF#15 showed a higher expression level of aldehyde dehydrogenase 1, β-catenin, cyclin D1, and pyruvate kinase M2 proteins in the skin of AA-TF#15-treated mice compared to that of those treated with minoxidil and oral finasteride. These findings suggest AA-TF#15 is an effective formulation for the treatment of scalp androgenic alopecia.

Finasteride for hair loss: a review

BACKGROUND AND OBJECTIVES

Finasteride 1 mg/day is indicated for androgen-dependent conditions such as male androgenetic alopecia (AGA).

METHODS

The literature is comprehensively summarized on the pharmacodynamics, pharmacokinetics, mechanism of action, and metabolism of finasteride. Pairwise and network meta-analyses were performed to assess the efficacy of finasteride reported in clinical trials. The adverse events profile is described along with the post-marketing reports.

RESULTS AND CONCLUSION

Finasteride 1 mg/day significantly increased total hair count compared to placebo after 24 weeks (mean difference = 12.4 hairs/cm², p < .05), and 48 weeks (mean difference = 16.4 hairs/cm², p < .05). The efficacy of the two doses of finasteride (5 mg/day and 1 mg/day) and topical finasteride (1% solution) were not significantly different. The most commonly reported sexual events include erectile dysfunction and decreased libido. Increasing patient complaints and analysis of the FAERS database led to the inclusion of depression in the FDA label in 2011, as men were found to be at a risk of suicide due to the persistent sexual side effects, commonly termed as post-finasteride syndrome. Finasteride is shown to be reasonably tolerated in both men and women; however, patients need to be educated about the possible short- and long-term side-effects.

Concomitant botanical medicine use among patients participating in commercial prostate cancer trials

OBJECTIVES

Patients with cancer frequently use botanical medications. The concomitant use of such medications by patients on commercial trials has not been well-described, despite the importance of these trials for evaluating the safety and efficacy of new agents. We sought to describe the use of botanical medications taken by patients with prostate cancer enrolled on global commercial trials.

DESIGN

Retrospective study.

SETTING

Regulatory repository of commercial clinical trial data.

INTERVENTIONS

Anti-cancer therapy.

MAIN OUTCOME MEASURES

Botanical and medication use data were pooled across six international commercial randomized trials for metastatic prostate cancer with detailed information on medication and indications. Botanical products were considered to have potential for drug interaction if they led to a change in drug exposure in human trials. Potential for interaction was ascertained by PubMed review. Descriptive statistics were used for analysis.

RESULTS

Of 7318 enrolled patients, 700 (10 %) reported botanical use at any time and 653 (9%) reported use of botanical products while on trial. Nearly half of botanical product types were not classified by plant (43 %). The highest proportion of botanical use was among patients in Asian countries (32 %), followed by patients in North America (13 %). Eighty-six different types of botanical products were used; of these, nineteen had a patient-reported anti-cancer indication.

CONCLUSIONS

Botanical medicine use among patients with prostate cancer in commercial trials is moderate, although it varies by region. Practitioners should be aware of the use of botanical interventions in a clinical trial context.

Drug Interactions with Gender-Affirming Hormone Therapy: Focus on Antiretrovirals and Direct Acting Antivirals

INTRODUCTION

Gender-affirming care may include hormonal therapy to attain desired health outcomes in transgender (trans) individuals. To provide safe, affirming medical care for trans patients, health care providers must identify and manage drug-drug interactions (DDIs) between gender affirming hormonal therapy (GAHT) and other medication therapies.

AREAS COVERED

This review summarizes available data on DDIs between GAHT and antiretrovirals (ARVs) or hepatitis C direct acting antivirals (DAAs). Potential pharmacokinetic and pharmacodynamic DDIs are predicted based on GAHT, ARV, and DAA pharmacology and adverse event profiles. Clinical management strategies are discussed.

EXPERT OPINION

GAHT may be involved in pharmacokinetic and/or pharmacodynamic DDIs. Certain ARV classes (non-nucleoside reverse transcriptase inhibitors, protease inhibitors) may alter GAHT disposition, whereas selected ARVs (unboosted integrase inhibitors, doravirine, or rilpivirine) may have less impact on GAHT. DAAs may interact with GAHT, but the clinical relevance is unclear. ARV- and/or DAA-associated side effects (including depression, cardiovascular disease, hyperlipidemia) are important to consider in the clinical management of trans patients. Clinicians must evaluate potential DDIs and overlapping side effects between ARVs, DAAs and GAHT when providing care for trans patients.

No Clinically Relevant Interactions of St. John's Wort Extract Ze 117 Low in Hyperforin With Cytochrome P450 Enzymes and P-glycoprotein

Hypericum perforatum L. (St. John's wort) is used to treat mild-to-moderate depression. Its potential safety risks are pharmacokinetic drug interactions via cytochrome P450 (CYP) enzymes and P-glycoprotein, presumably caused by hyperforin. In a phase I, open-label, nonrandomized, single-sequence study, the low-hyperforin Hypericum extract Ze 117 was investigated using a drug cocktail in 20 healthy volunteers. No pharmacokinetic interactions of Ze 117 were observed for CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP3A4, and P-glycoprotein. Area under the curve (AUC) and peak plasma concentration (C_max ) of the used probe drugs showed 90% confidence intervals (CIs) of the geometric mean ratios of the drugs taken together with Ze 117 vs. probe drug alone, well within the predefined bioequivalence range of 80-125%. Though Ze 117 did not induce dextromethorphan metabolism by CYP2D6, it weakly increased dextromethorphan AUC ratio (mean 147.99, 95% CI 126.32-173.39) but not the corresponding metabolic ratio. Ze 117 does not show clinically relevant pharmacokinetic interactions with important CYPs and P-glycoprotein.

Understanding drug interactions with St John's wort (Hypericum perforatum L.): impact of hyperforin content

Objective

The aim of this study was to review herb–drug interaction studies with St John's wort (Hypericum perforatum L.) with a focus on the hyperforin content of the extracts used in these studies.

Methods

PUBMED was systematically searched to identify studies describing pharmacokinetic interactions involving St John's wort. Data on study design and the St John's wort extract or product were gathered to extract hyperforin content and daily dose used in interaction studies.

Key findings

This analysis demonstrates that significant herb–drug interactions (resulting in a substantial change in systemic exposure) with St John's wort products were associated with hyperforin daily dosage. Products that had a daily dose of &lt;1 mg hyperforin were less likely to be associated with major interaction for drugs that were CYP3A4 or p-glycoprotein substrates. Although a risk of interactions cannot be excluded even for low-dose hyperforin St. John's wort extracts, the use of products that result in a dose of not more than 1 mg hyperforin per day is recommended to minimise the risk of interactions.

Conclusions

This review highlights that the significance of herb–drug interactions with St John's wort is influenced by the nature of the herbal medicines product, particularly the hyperforin content.

Medicinal herbs and therapeutic drugs interactions

People mistakenly think that all herbs are safe, because of the fact that they are natural, and the use of herbal medication is growing. Aspects of the efficacy, safety, and quality of herbal or natural products are the subjects of on-going debates. Concurrent administration of herbs may interfere with the effect of drugs. Lack of knowledge of the interaction potential together with an underreporting of herbal use poses a challenge for health care providers and a safety concern for patients. A good understanding of the mechanisms of herb-drug interactions is also essential for assessing and minimizing clinical risks. Examples of herbal medicine-pharmaceutical drug interactions of commonly used herbs are presented. The potential pharmacokinetic and pharmacodynamic basis of such interactions is discussed, as well as the challenges associated with the identification and prediction of herb-drug interactions.

Prevalence and correlates of postdiagnosis initiation of complementary and alternative medicine among patients at a comprehensive cancer center

PURPOSE

Patients with cancer increasingly use complementary and alternative medicine (CAM) in conjunction with conventional oncology treatments. Previous studies have not investigated postdiagnosis initiation of CAM therapies or independent correlates of use of individual CAM modalities. The purpose of this study was to determine the prevalence and correlates of individual CAM modalities initiated after cancer diagnosis.

METHODS

A cross-sectional survey was conducted of a random sample of adults with a cancer diagnosis (N = 1,228) seeking care at a National Cancer Institute-designated comprehensive cancer center within a 12-month period.

RESULTS

The majority of patients were female (64.7%), white (86.9%), and married (72.8%).Three-quarters (75.2%) used at least one CAM modality, and 57.6% of those using CAM initiated use after cancer diagnosis. For all CAM therapies combined, women were 1.7 times more likely than men to initiate any CAM therapy after cancer diagnosis. However, when CAM modalities were differentiated by type, men and women were equally likely to initiate all therapies except for psychotherapy and mind-body approaches. Postdiagnosis initiation of every CAM modality, except mind-body therapies, differed by cancer type.

CONCLUSION

A significant proportion of patients initiated CAM use after diagnosis. However, specific type of CAM initiated varied by demographics and cancer type, suggesting there is not a "typology" of CAM user. Optimal comprehensive cancer treatment, palliation, and survivorship care will require patient and provider education regarding CAM use by modality type; improved provider-patient communication regarding potential benefits, limitations, and risks; and institutional policies to support integrated conventional and CAM treatment.

In vivo investigation in pigs of intestinal absorption, hepatobiliary disposition, and metabolism of the 5α-reductase inhibitor finasteride and the effects of coadministered ketoconazole

The overall aim of this detailed investigation of the pharmacokinetics (PK) and metabolism of finasteride in pigs was to improve understanding of in vivo PK for this drug and its metabolites. Specific aims were to examine the effects of ketoconazole coadministration on the PK in three plasma compartments (the portal, hepatic, and femoral veins), bile, and urine and to use these data to study in detail the intestinal absorption and the liver extraction ratio and apply a semiphysiological based PK model to the data. The pigs received an intrajejunal dose of finasteride (0.8 mg/kg) either alone (n = 5) or together with ketoconazole (10 mg/kg) (n = 5) or an intravenous dose (0.2 mg/kg) (n = 3). Plasma, bile, and urine (collected from 0 to 6 h) were analyzed with ultraperformance liquid chromatography-tandem mass spectrometry. Ketoconazole increased the bioavailability of finasteride from 0.36 ± 0.23 to 0.91 ± 0.1 (p < 0.05) and the terminal half-life from 1.6 ± 0.4 to 4.0 ± 1.1 h (p < 0.05). From deconvolution, it was found that the absorption rate from the intestine to the portal vein was rapid, and the product of the fraction absorbed and the fraction that escaped gut wall metabolism was high (f(a) · F(G) ∼ 1). Interestingly, the apparent absorption rate constant (k(a)) to the femoral vein was lower than that to the portal vein, probably because of binding and distribution within the liver. The liver extraction ratio was time-dependent and varied with the two routes of administration. After intrajejunal administration, from 1 to 6 h, the liver extraction ratio was significantly (p < 0.05) reduced by ketoconazole treatment from intermediate (0.41 ± 0.21) to low (0.21 ± 0.10).

Finasteride metabolism and pharmacogenetics: new approaches to personalized prevention of prostate cancer

Incidences of prostate cancer in most countries are increasing owing to better detection methods; however, prevention with the use of finasteride, a very effective steroid 5α-reductase type II inhibitor, has been met with mixed success. A wide interindividual variation in response exists and is thought to be due to heritable factors. This article summarizes the literature that attempts to elucidate the molecular mechanisms of finasteride in terms of its metabolism, excretion and interaction with endogenous steroid molecules. We describe previously reported genetic variations of steroid-metabolizing genes and their potential association with finasteride efficacy. Based on the literature, we outline directions of research that may contribute to understanding the interindividual variation in finasteride prevention and to the future development of personalized medicine.

Herb-drug pharmacokinetic interactions reviewed

IMPORTANCE OF THE FIELD

the global increase in the popularity of alternative medicines has raised renewed concerns regarding herb-drug interactions. These interactions are especially important for drugs with narrow therapeutic indices and may either be pharmacodynamic or pharmacokinetic in nature.

AREAS COVERED IN THIS REVIEW

pharmacokinetic interactions which may exist between herbs and drugs, and the mechanisms of these interactions with appropriate examples based on primary and secondary data in publications are discussed. The mechanisms covered include those that affect oral drug absorption (e.g., modulation of efflux and uptake transporters, complex formation, gastrointestinal motility and pH) and drug biotransformation (e.g., inhibition or induction of enzymes).

WHAT THE READER WILL GAIN

knowledge on the mechanisms of herb-drug pharmacokinetic interactions supported by an extended list of these types of interactions for quick reference. A critical evaluation of certain herb-drug pharmacokinetic interactions reported in the scientific literature.

TAKE HOME MESSAGE

as the incidence and severity of herb-drug pharmacokinetic interactions increase due to a worldwide rise in the use of herbal preparations, more clinical data regarding herb-drug pharmacokinetic interactions are needed to make informed decisions regarding patient safety.

Identification of finasteride metabolites in human bile and urine by high-performance liquid chromatography/tandem mass spectrometry

The objective of this study was to further investigate the metabolism of the 5alpha-reductase inhibitor, finasteride, and to identify previously unknown phase I and phase II metabolites in vitro and in vivo in human bile and urine. Healthy volunteers were given 5 mg of finasteride, directly to the intestine, and bile and urine were collected for 3 and 24 h, respectively. A single-pass perfusion technique, Loc-I-Gut, was used for drug administration and bile collection from the proximal jejunum, distal to papilla of Vater. Incubations with human liver microsomes/S9 fractions and different cofactors were performed with finasteride and the previously known metabolites, omega-hydroxy finasteride (M1) and finasteride-omega-oic acid (M3). Liquid chromatography coupled to triple quadrupole mass spectrometry (MS) with positive/negative electrospray ionization and ion trap with MS(n) measurements were used for structural investigations and identification of metabolites. Two hydroxy metabolites of finasteride, other than M1, and one intact hydroxy finasteride glucuronide were identified in vitro and in bile and urine. The glucuronide and at least one of the hydroxy metabolites were previously unidentified. M1 and M3 were glucuronidated in vitro by specific human UDP-glucuronosyltransferases, UGT1A4 and UGT1A3, respectively. M1 glucuronide was not identified in vivo, and M3 glucuronide, an acyl glucuronide, was present in low amounts in bile from a few individuals. In conclusion, previously undescribed metabolites were identified, in vitro and in human urine and bile. Bile collection using the Loc-I-Gut technique followed by sensitive mass spectrometry analysis led to the discovery of novel, both phase I and phase II, finasteride metabolites in human bile.