Co-administration of St. John's wort and hormonal contraceptives: a systematic review

U.S. Medical Eligibility Criteria for Contraceptive Use, 2024

The 2024 U.S. Medical Eligibility Criteria for Contraceptive Use (U.S. MEC) comprises recommendations for the use of specific contraceptive methods by persons who have certain characteristics or medical conditions. These recommendations for health care providers were updated by CDC after review of the scientific evidence and a meeting with national experts in Atlanta, Georgia, during January 25-27, 2023. The information in this report replaces the 2016 U.S. MEC (CDC. U.S. Medical Eligibility Criteria for Contraceptive Use, 2016. MMWR 2016:65[No. RR-3]:1-103). Notable updates include 1) the addition of recommendations for persons with chronic kidney disease; 2) revisions to the recommendations for persons with certain characteristics or medical conditions (i.e., breastfeeding, postpartum, postabortion, obesity, surgery, deep venous thrombosis or pulmonary embolism with or without anticoagulant therapy, thrombophilia, superficial venous thrombosis, valvular heart disease, peripartum cardiomyopathy, systemic lupus erythematosus, high risk for HIV infection, cirrhosis, liver tumor, sickle cell disease, solid organ transplantation, and drug interactions with antiretrovirals used for prevention or treatment of HIV infection); and 3) inclusion of new contraceptive methods, including new doses or formulations of combined oral contraceptives, contraceptive patches, vaginal rings, progestin-only pills, levonorgestrel intrauterine devices, and vaginal pH modulator. The recommendations in this report are intended to serve as a source of evidence-based clinical practice guidance for health care providers. The goals of these recommendations are to remove unnecessary medical barriers to accessing and using contraception and to support the provision of person-centered contraceptive counseling and services in a noncoercive manner. Health care providers should always consider the individual clinical circumstances of each person seeking contraceptive services. This report is not intended to be a substitute for professional medical advice for individual patients; when needed, patients should seek advice from their health care providers about contraceptive use.

Systematic analysis of combined oral contraceptive prescription patterns in psychotropic drug users across twelve European countries

OBJECTIVE

To investigate prescription patterns of combined oral contraceptives (COC) among psychotropic drug users compared to non-psychotropic drug users in routine clinical practice in Europe.

STUDY DESIGN

A pooled analysis of three large, prospective, multinational cohort studies including women with a new prescription of COC from 12 European countries. We calculated standardized mean differences (SMD) to investigate whether the status of psychotropic drug use (use/no use) or the psychotropic drug class (psycholeptics/psychoanaleptics) is associated with the healthcare professional's choice of a specific type of COC progestin.

RESULTS

Our analysis comprised 143,069 non-psychotropic drug users and 2174 psychotropic drug users. Progestins with the highest frequency in the cohorts were levonorgestrel (non-psychotropic drug users: 33.8%; psychotropic drug users: 32.4%), nomegestrol/nomegestrol acetate (non-psychotropic drug users: 19.1%; psychotropic drug users: 26.4%), and drospirenone (non-psychotropic drug users: 15.9%; psychotropic drug users: 14.8%). SMD analysis indicated no substantial differences in COC prescription patterns between the two cohorts. However, we observed association signals for users of the herbal antidepressant St. John's wort in that those individuals more often received a prescription for drospirenone and less frequently for nomegestrol/nomegestrol acetate compared to non-psychotropic drug users.

CONCLUSIONS

Psychotropic drug user status does not seem to affect healthcare professionals' decisions when prescribing COC. However, limited evidence suggests that the risk for drug interactions might differ by progestin type, and some COC might be more suitable for psychotropic drug users than others. Specific guidelines should be conveyed to healthcare professionals to assist them in contraceptive counseling.

IMPLICATIONS

With exception of St. John's wort, our analysis showed no differential prescription behavior of combined oral contraceptives in psychotropic drug users and non-users. However, healthcare professionals should carefully consider psychotropic drug use in contraceptive counseling as it is still unclear whether drug interactions exist when co-administered with certain oral contraceptives.

Herbal Supplement Use Among Adolescent and Young Adult Women in a Family Planning Clinic

STUDY OBJECTIVE

We aimed to evaluate herbal medicine and supplement use patterns among adolescent and young adult women at a clinic focused on family planning.

METHODS

We conducted a cross-sectional survey of patients (age 14-25) at an adolescent Title X clinic. Participants completed an electronic survey that assessed herbal medicine and supplement use, baseline demographic characteristics, and current contraceptive method. We evaluated supplement-drug interactions using the Natural Medicines database Interaction Checker. Quantitative analyses were performed using χ2 and independent medians tests.

RESULTS

We enrolled 99 participants with a median age of 20 (15-24) years. Overall, 42.4% of patients reported ever having used supplements or herbal medicines, with 29.9% of patients reporting current supplement or herbal medicine use. Patients with higher education and private insurance were more likely to report a history of and current supplement use (P < .05). The most common herbal supplements reported were green tea (n = 26), cannabidiol (n = 17), and cranberry (n = 16), with 29.6% of participants reporting use to their general health care provider. The most common reasons for use were general health and wellness (29.1%), immune support (23.2%), stress (16.8%), and menstrual irregularities (6.0%). We found 62 moderate risk supplement-drug interactions, with 50 interactions attributed to hormonal contraceptive therapies. The most common interactions were via cytochrome P450 enzyme (CYP3A4 or CYP1A2) inhibition, decreased caffeine clearance, and potential hepatotoxicity.

CONCLUSION

Adolescent and young adult women frequently reported past and current herbal medicine and supplement use, with high rates of moderate-risk supplement-drug interactions. Further research is needed to better elucidate these clinically relevant supplement-contraception interactions.

Drug-Drug Interactions With Over-The-Counter Medicines: Mind the Unprescribed

BACKGROUND

This review provides a summary of the currently available clinical data on drug-drug interactions (DDIs) involving over-the-counter (OTC) medicines. It aims to educate and increase awareness among health care providers and to support decisions in daily practice.

METHODS

An extensive literature search was performed using bibliographic databases available through PubMed.gov. An initial structured search was performed using the keywords "drug-drug-interaction AND (over-the-counter OR OTC)," without further restrictions except for the language. The initial results were screened for all described DDIs involving OTC drugs, and further information was gathered specifically on these drugs using dedicated database searches and references found in the bibliography from the initial hits.

RESULTS

From more than 1200 initial hits (1972-June 2021), 408 relevant publications were screened for DDIs involving OTC drugs, leading to 2 major findings: first, certain types of drug regimens are more prone to DDIs or have more serious DDI-related consequences, such as antiretroviral, anti-infective, and oral anticancer therapies. Second, although most DDIs involve OTC drugs as the perpetrators, some prescription drugs (statins or phosphodiesterase-5 inhibitors) that currently have OTC status can be identified as the victims in DDIs. The following groups were identified to be frequently involved in DDIs: nonsteroidal anti-inflammatory drugs, food supplements, antacids, proton-pump inhibitors, H2 antihistamines, laxatives, antidiarrheal drugs, and herbal drugs.

CONCLUSIONS

The most significant finding was the lack of high-quality evidence for commonly acknowledged interactions. High-quality interaction studies involving different phenotypes in drug metabolism (cytochrome P450) and distribution (transporters) are urgently needed. This should include modern and critical drugs, such as oral anticancer medications and direct oral anticoagulants.

Hormonal Contraception: Systemic Estrogen and Progestin Preparations

Combined hormonal contraception (CHC) are short-acting, reversible methods containing both estrogen and progestin. Available CHC methods include combined oral contraceptives, transdermal patches, and vaginal rings. The combined oral contraceptive remains the most commonly used contraceptive method in the United States. The general principles of CHC will be reviewed, including mechanism of action and effectiveness. Unless otherwise stated, these principles apply to all CHCs. When discussing clinical studies and specific considerations related only to pills, patches, or rings, the method(s) will be specified. Words that specify sex are used when discussing studies in which sex was specified.

The Overview on the Pharmacokinetic and Pharmacodynamic Interactions of Triazoles

Second generation triazoles are widely used as first-line drugs for the treatment of invasive fungal infections, including aspergillosis and candidiasis. This class, along with itraconazole, voriconazole, posaconazole, and isavuconazole, is characterized by a broad range of activity, however, individual drugs vary considerably in safety, tolerability, pharmacokinetics profiles, and interactions with concomitant medications. The interaction may be encountered on the absorption, distribution, metabolism, and elimination (ADME) step. All triazoles as inhibitors or substrates of CYP isoenzymes can often interact with many drugs, which may result in the change of the activity of the drug and cause serious side effects. Drugs of this class should be used with caution with other agents, and an understanding of their pharmacokinetic profile, safety, and drug-drug interaction profiles is important to provide effective antifungal therapy. The manuscript reviews significant drug interactions of azoles with other medications, as well as with food. The PubMed and Google Scholar bases were searched to collect the literature data. The interactions with anticonvulsants, antibiotics, statins, kinase inhibitors, proton pump inhibitors, non-nucleoside reverse transcriptase inhibitors, opioid analgesics, benzodiazepines, cardiac glycosides, nonsteroidal anti-inflammatory drugs, immunosuppressants, antipsychotics, corticosteroids, biguanides, and anticoagulants are presented. We also paid attention to possible interactions with drugs during experimental therapies for the treatment of COVID-19.

A Drug-Drug Interaction Study to Investigate the Effect of Nintedanib on the Pharmacokinetics of Microgynon (Ethinylestradiol and Levonorgestrel) in Female Patients with Systemic Sclerosis-Associated Interstitial Lung Disease

Background and Objectives

Nintedanib is a tyrosine kinase inhibitor approved for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD), idiopathic pulmonary fibrosis, and other chronic fibrosing ILDs with a progressive phenotype. As nintedanib may cause foetal harm, patients taking nintedanib should avoid pregnancy. The objective of this study was to investigate the effect of nintedanib co-administration on the pharmacokinetics of Microgynon (ethinylestradiol and levonorgestrel) in female patients with SSc-ILD.

Methods

This was an open-label, two-period, fixed-sequence, drug–drug interaction study. Female patients with SSc and ≥ 10% extent of fibrotic ILD on a high-resolution computed tomography scan were eligible to participate. In Period 1, patients received one Microgynon tablet (ethinylestradiol 30 μg and levonorgestrel 150 μg) ≥ 3 days before the first administration of nintedanib in Period 2. In Period 2, patients received one Microgynon tablet following intake of nintedanib 150 mg twice daily for ≥ 10 consecutive days. The primary pharmacokinetic endpoints were the areas under the plasma concentration–time curve of ethinylestradiol and levonorgestrel over the time interval from 0 to the last quantifiable data point (AUC_0–tz) and the maximum measured concentrations of ethinylestradiol and levonorgestrel in plasma (C_max). The secondary pharmacokinetic endpoint was the area under the plasma concentration–time curve of ethinylestradiol and levonorgestrel over the time interval from 0 extrapolated to infinity (AUC_0–∞). The relative exposures of ethinylestradiol and levonorgestrel when administered alone and in combination with nintedanib were assessed using an ANOVA model.

Results

Seventeen patients were treated. Pharmacokinetic data from 15 patients were analysed. Plasma concentration–time profiles of ethinylestradiol and levonorgestrel were similar following administration of Microgynon before and after administration of nintedanib for ≥ 10 consecutive days. Adjusted geometric mean (gMean) ratios [90% confidence intervals (CIs)] for AUC_0‒tz (101.4% [92.8, 110.7]) and AUC_0‒∞ (101.2% [94.0, 109.1]) indicated that there was no difference in total ethinylestradiol exposure when Microgynon was administered before or after administration of nintedanib. The adjusted gMean ratio for C_max of ethinylestradiol (116.7% [90% CI 107.6, 126.5]) indicated an increase in peak exposure in the presence of nintedanib. Adjusted gMean ratios [90% CIs] for AUC_0-tz (96.4% [91.5, 101.6]) and C_max (100.9% [89.9, 113.2]) indicated that there was no difference in total or peak levonorgestrel exposure when Microgynon was administered before or after administration of nintedanib. The adjusted gMean ratio for AUC_0‒∞ of levonorgestrel indicated a decrease in total exposure in the presence of nintedanib (88.1% [90% CI 80.0, 97.0]).

Conclusion

Pharmacokinetic data indicate that there is no relevant effect of nintedanib on plasma exposure to ethinylestradiol and levonorgestrel in female patients with SSc-ILD.

Trial Registration

Clinicaltrials.gov NCT03675581.

Characterization of pregnancies exposed to St. John's wort and their outcomes: A claims data analysis

Little is known about the utilization of St. John's wort (Hypericum perforatum L.) during pregnancy. In Germany, certain preparations of St. John's wort can be reimbursed by statutory health insurances, facilitating to investigate exposure to St. John's wort based on claims data. We therefore aimed to characterize pregnancies exposed to St. John's wort and to explore potential malformations in the babies. Using claims data from the German Pharmacoepidemiological Research Database (GePaRD), pregnancies exposed to St. John's wort during at least one trimester between 2006 and 2016 and the corresponding babies were identified. Exposure was identified via outpatient dispensations. Pregnancies were characterized regarding timing of exposure, use of other antidepressants, pregnancy outcomes and the occurrence of major malformations in the babies (not considering codes for musculoskeletal and other malformations due to low data quality in this regard). Out of 496 pregnancies with a dispensation of St. John's wort during pregnancy, 420 (85 %) had a dispensation during the first trimester. There was a dispensation of other antidepressants before pregnancy in 21 % (during pregnancy: 12 %). Eleven percent of pregnancies ended in non-live births. In 312 babies linked to 305 pregnancies, major malformations were coded in 18 babies (5.8 %), of which 17 were exposed in the first trimester. The crude relative risk of major malformations for babies exposed during the first vs. the second or third trimester only was 3.56 (0.48-26.17). Our results suggest that only in a minority of pregnancies, St. John's wort is used as an alternative to other antidepressants. Even though the relatively high rates of non-live births and major malformations after exposure to St. John's wort during the first trimester need to be interpreted with caution, the findings are striking and generate hypotheses that merit further investigation.

Contraception for Women With Psychiatric Disorders

OBJECTIVE

Mental health care for women includes decision support to prepare for major life events, including preconception planning for treatment during pregnancy and the postpartum period. The authors discuss contraceptive choices and their effectiveness, side effects, and impact on psychiatric symptoms. The Centers for Disease Control and Prevention's recommendations, Medical Eligibility Criteria for Contraceptive Use, provided the structure for review of contraceptive choices.

METHODS

A search of PsycINFO, PubMed, Embase, and Scopus was conducted for publications on the management of contraception for women with mental illness. Publications were selected if they included, based on the authors' consensus, data supporting evidence-based care important for psychiatrists who treat women desiring contraceptives.

RESULTS

The majority of women choose combined oral contraceptives. Although long-acting reversible contraceptives (implants, intrauterine devices) are associated with low failure rates, favorable safety profiles, rapid return to fertility after removal, and few contraindications, they are chosen by only 14% of women. All methods are acceptable for women with depression, although medical comorbidities may dictate a specific type. The impact of hormonal contraceptives on the risk for depression is controversial; however, clinical studies and randomized placebo-controlled trials of women with psychiatric disorders have generally reported similar or lower rates of mood symptoms in hormonal contraceptive users compared with nonusers. Although interactions between psychotropic drugs and contraceptives are rare, clozapine, anticonvulsants, and St. John's Wort are exceptions.

CONCLUSIONS

Proactive management of mental illness, contraception, and pregnancy improves a woman's capacity to function and optimizes her mental and reproductive health.

Herbal supplements interactions with oral oestrogen-based contraceptive metabolism and transport

The increased use of herbal supplements as complementary or alternative medicines has become a clinical conundrum due to the potential for herb-drug interactions. This is exacerbated by an increased supply of new herbal supplements in the market claiming various health advantages. These herbal supplements are available as over-the-counter self-medications. Herbal supplements are generally perceived as efficacious without side effects commonly associated with conventional drugs. However, despite regulations, claims related to their therapeutic effects are mostly unsupported by scientific evidence. These products often lack suitable product quality controls, labelled inadequately and with batch to batch variations, potentially compromising the safety of the consumer. Amongst health practitioners, the greatest concern is related to the lack of chemical characterization of the active compounds of the herbal supplements. The interaction between these different active components and their concomitant effects on other conventional drugs is generally not known. This review will focus on herbal supplements with the potential to effect pharmacokinetic and pharmacodynamic properties of oestrogen-based oral contraceptives. The use of herbal supplements for weight management, depression, and immune boosting benefits were selected as likely herbal supplements to be used concomitantly by women on oral contraceptives.

ACOG Practice Bulletin No. 206: Use of Hormonal Contraception in Women With Coexisting Medical Conditions

Although numerous studies have addressed the safety and effectiveness of hormonal contraceptive use in healthy women, data regarding women with underlying medical conditions or other special circumstances are limited. The U.S. Medical Eligibility Criteria (USMEC) for Contraceptive Use, 2016 (), which has been endorsed by the American College of Obstetricians and Gynecologists, is a published guideline based on the best available evidence and expert opinion to help health care providers better care for women with chronic medical problems who need contraception. The goal of this Practice Bulletin is to explain how to use the USMEC rating system in clinical practice and to specifically discuss the rationale behind the ratings for various medical conditions. Contraception for women with human immunodeficiency virus (HIV) (); the use of emergency contraception in women with medical coexisting medical conditions, including obesity, (); and the effect of depot medroxyprogesterone acetate (DMPA) on bone health () are addressed in other documents from the American College of Obstetricians and Gynecologists.

No. 329-Canadian Contraception Consensus Part 4 of 4 Chapter 9: Combined Hormonal Contraception

OBJECTIVE

To provide guidelines for health care providers on the use of contraceptive methods to prevent pregnancy and on the promotion of healthy sexuality.

OUTCOMES

Overall efficacy of cited contraceptive methods, assessing reduction in pregnancy rate, safety, and side effects; the effect of cited contraceptive methods on sexual health and general well-being; and the availability of cited contraceptive methods in Canada.

EVIDENCE

Medline and the Cochrane Database were searched for articles in English on subjects related to contraception, sexuality, and sexual health from January 1994 to December 2015 in order to update the Canadian Contraception Consensus published February-April 2004. Relevant Canadian government publications and position papers from appropriate health and family planning organizations were also reviewed.

VALUES

The quality of the evidence is rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. Recommendations for practice are ranked according to the method described in this report.

SUMMARY STATEMENTS

RECOMMENDATIONS.

"Complementary Medicine": Complementary and Alternative Health Approaches in Pediatric and Adolescent Gynecology

Complementary and alternative health care approaches are prevalent in the patients and families served by practitioners in pediatric and adolescent gynecology. This article addresses gaps in knowledge, including new terminology, prevalence of use, rates of and reasons behind nondisclosure, and potential interactions of herbal products with prescribed medication. It closes with practical complementary health approaches to the adolescent with dysmenorrhea.

[Drug and food interactions with contraceptives: CNGOF Contraception Guidelines]

INTRODUCTION

The risk of drug interaction with hormonal contraceptives should be anticipated as it may lead to unplanned pregnancies. These are frequently reported with some drugs, such as antiepileptics, and with some contraceptive methods, such as the implant, not always understood by patients as hormonal contraception.

OBJECTIVES

The aim of this work was to review all drugs and foods at risk of interaction with contraceptives.

METHODS

The official recommendations established by the French Agency for the safety of medicinal products have been taken into account, supported by a review of the literature.

RESULTS

There is a risk of drug-drug interaction with all hormonal contraceptives regardless of their route of administration. Most interactions lead to a decrease in the effectiveness of hormonal contraceptives. If an enzyme inducer drug is started in a woman with an hormonal contraception, it is recommended, if the treatment is short, to use an additional mechanical contraception (barrier method) for the duration of the treatment and the cycle following its arrest and if the treatment is long, it is recommended to choose a non-hormonal contraceptive method. On the contrary, some drugs may increase ethinylestradiol levels and potentially the risk of complications. Exceptionally, it is the hormonal contraceptive that will alter the pharmacokinetics of another drug, for example, lamotrigine.

CONCLUSIONS

The risk of drug interaction leading to a decrease in the contraceptive effectiveness needs to be known to prescribers in order to be taken into account when prescribing any new drug in a woman with hormonal contraception (and whatever its route of administration).

Associations between complementary medicine utilisation and the use of contraceptive methods: Results of a national cross-sectional survey

BACKGROUND AND PURPOSE

This study examines the relationship between the use of complementary medicine (CM) interventions or consultations with CM practitioners and women's choice of contraceptive method.

MATERIALS AND METHODS

A secondary analysis of a cross-sectional survey of Australian Women aged 34-39 years from the Australian Longitudinal Study on Women's Health (ALSWH) was conducted. Associations between use of CM and contraception were analysed using Chi-squared tests and multivariate logistic regression.

RESULTS

Based on the responses from the included women (n = 7299), women who consulted a naturopath/herbalist were less likely to use implant contraceptives (OR 0.56; 95% confidence interval (CI) 0.33; 0.95). Those consulting a chiropractor (OR 1.54; 95%CI 1.05; 2.25) or an osteopath (OR 2.16; 95% CI 1.32; 3.54) were more likely to use natural contraception.

CONCLUSION

There may be a link between women's choice of contraceptive method and their use of CM, in particular, with CM practitioner consultations.

A strategic action framework for multipurpose prevention technologies combining contraceptive hormones and antiretroviral drugs to prevent pregnancy and HIV

OBJECTIVE

Multipurpose prevention technologies (MPTs) are an innovative class of products that deliver varied combinations of human immunodeficiency virus (HIV) prevention, other sexually transmitted infection (STI) prevention, and contraception. Combining separate strategies for different indications into singular prevention products can reduce the stigma around HIV and STI prevention, improve acceptability of and adherence to more convenient products, and be more cost-effective by addressing overlapping risks.

METHODS

This article outlines a strategic action framework developed as an outcome of a series of expert meetings held between 2014 and 2016. The meetings focused on identifying opportunities and challenges for MPTs that combine hormonal contraception (HC) with antiretroviral drugs into single products. The framework aims to present an actionable strategy, by addressing key research gaps and outlining the key areas for progress, to guide current and future HC MPT development.

RESULTS

We identified eight primary action areas for the development of impactful HC MPTs, and includes aspects from epidemiology, pharmacology, clinical trial design, regulatory requirements, manufacturing and commercialisation, behavioural science, and investment needs for research and development.

CONCLUSION

Overall, the challenges involved with reconciling the critical social-behavioural context that will drive MPT product use and uptake with the complexities of research and development and regulatory approval are of paramount importance. To realise the potential of MPTs given their complexity and finite resources, researchers in the MPT field must be strategic about the way forward; increased support among policy-makers, advocates, funders and the pharmaceutical industry is critical.

PXR as a mediator of herb–drug interaction

Medicinal herbs have been a part of human medicine for thousands of years. The herb–drug interaction is an extension of drug–drug interaction, in which the consumptions of herbs cause alterations in the metabolism of drugs the patients happen to take at the same time. The pregnane X receptor (PXR) has been established as one of the most important transcriptional factors that regulate the expression of phase I enzymes, phase II enzymes, and drug transporters in the xenobiotic responses. Since its initial discovery, PXR has been implicated in multiple herb–drug interactions that can lead to alterations of the drug’s pharmacokinetic properties and cause fluctuating therapeutic efficacies, possibly leading to complications. Regions of the world that heavily incorporate herbalism into their primary health care and people turning to alternative medicines as a personal choice could be at risk for adverse reactions or unintended results from these interactions. This article is intended to highlight our understanding of the PXR-mediated herb–drug interactions.

Use of Dicloxacillin and Risk of Pregnancy among Users of Oral Contraceptives

The antibiotic dicloxacillin has been shown to induce drug-metabolizing CYP enzymes to a clinically relevant extent. In this study, we investigated whether the use of dicloxacillin confers an increased risk of unwanted pregnancy among oral contraceptive users. The study population comprised Danish women falling pregnant (1997-2015) during oral contraceptive use, defined as having filled a prescription for an oral contraceptive within 120 days both before and after the estimated date of conception. Data were analysed using a case-crossover approach. For each woman, we assessed the use of dicloxacillin preceding the date of conception and during 10 previous control periods and estimated the odds ratio for such unintended pregnancies associated with the use of dicloxacillin. Among 364 women using dicloxacillin prior to conception, 40 (11%) were exposed to dicloxacillin at the time of conception, yielding an odds ratio (OR) associating use of dicloxacillin to unintended pregnancy of 1.18 (95% CI 0.84-1.65). Supplementary and sensitivity analyses generally returned similar estimates, except for a slightly increased risk among users of progestogen-only oral contraceptives (OR 1.83, 95% CI 0.63-5.34). Analysis of other antibiotics as negative controls yielded results close to unity (ORs ranging from 0.83 to 1.13). In conclusion, our study found no evidence for an increased risk of oral contraceptive failure when using dicloxacillin. However, acknowledging study limitations, we suggest the use of supplementary barrier methods during treatment with dicloxacillin, until our findings are confirmed in further studies.

St John's wort (Hypericum perforatum)-induced psychosis: a case report

BACKGROUND

St John's wort (Hypericum perforatum) has been known for centuries for its therapeutic properties and its efficacy as an antidepressant has been confirmed by a growing body of evidence. During the last two decades it has also come to prominence with a wider public, due to advertising efforts across Europe and United States of America. However, its availability without prescription, as an over-the-counter medication, raises some concern regarding its clinical management and unsupervised administration to individuals with psychopathological risks. To date, the evidence available regarding the administration of Hypericum in people with severe mental health problems is still meager and refers mainly to affective disorder spectrum or psychotic relapse in people with established diagnoses. To the best of our knowledge, this is the first report regarding the onset of psychotic features in a patient presenting with psychotic diathesis.

CASE PRESENTATION

The case discussed in this report is a 25-year-old white man, not known to the psychiatric services, with a history of brief and self-remitting drug-induced psychosis and a positive family history of psychotic depression. He was admitted to hospital due to the onset of florid psychotic symptoms concomitant with self-administration of Hypericum perforatum.

CONCLUSIONS

The aim of this report is to promote further systematic research, draw the attention of clinicians to the potential risks of Hypericum precipitating psychosis, and raise awareness among health professionals to investigate and caution their patients on the haphazard use of phytotherapeutics such as Hypericum.