Publications by authors named "Irene Scholz"

5 Publications

  • Page 1 of 1

Effects of Hypericum perforatum (St John's wort) on the pharmacokinetics and pharmacodynamics of rivaroxaban in humans.

Br J Clin Pharmacol 2021 Mar 25;87(3):1466-1474. Epub 2020 Oct 25.

Clinical Pharmacology and Toxicology, Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland.

Aims: To investigate the influence of a cytochrome P450 CYP3A4 and efflux transporter P-glycoprotein (P-gp) inducing Hypericum perforatum extract on the pharmacokinetics and pharmacodynamics of rivaroxaban.

Methods: Open-label, nonrandomized, sequential treatment interaction study. Following CYP3A4 and P-gp phenotyping using low-dose midazolam and fexofenadine, 12 healthy volunteers received a single oral dose of 20 mg rivaroxaban and rivaroxaban plasma concentrations and inhibition of the activated coagulation factor X (factor Xa) activity were measured prior to and up to 48 h postdosing. The procedures were repeated after 2 weeks' treatment with the H. perforatum extract.

Results: The geometric mean ratios for the area under the concentration-time curve and C of rivaroxaban after/before induction with the H. perforatum extract were 0.76 (90% confidence interval [CI] 0.70, 0.82) and 0.86 (90% CI 0.76, 0.97), respectively. Inhibition of factor Xa activity was reduced with a geometric mean area under the effect-time curve ratio after/before induction of 0.80 (90% CI 0.71, 0.89). No clinically significant differences were found regarding T (median 1.5 vs 1 h, P = .26) and terminal elimination half-life (mean 10.6 vs 10.8 h, P = .93) of rivaroxaban. The H. perforatum extract significantly induced CYP3A4 and P-gp activity, as evidenced by phenotyping.

Conclusion: The CYP3A4/P-gp inducing H. perforatum extract caused a decrease of rivaroxaban exposure with a proportional decrease of the pharmacodynamic effect. Although the data do not justify a contraindication for the combination or a systematic adjustment of rivaroxaban dosage, avoidance of the combination or laboratory monitoring should be considered in patients taking hyperforin-containing H. perforatum extracts with rivaroxaban.
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March 2021

MDMA-related presentations to the emergency departments of the European Drug Emergencies Network plus (Euro-DEN Plus) over the four-year period 2014-2017.

Clin Toxicol (Phila) 2021 02 17;59(2):131-137. Epub 2020 Jul 17.

Division of Clinical Pharmacology and Toxicology, Institute of Pharmacological Sciences of Southern Switzerland, Ente Ospedaliero Cantonale, Lugano, Switzerland.

Context: 3,4-Methylenedioxymethamphetamine (MDMA) remains one of the most commonly used recreational drugs in Europe. Monitoring of Emergency Department (ED) presentations with acute toxicity associated with MDMA is important to determine trends in MDMA use and harms.

Methods: Data were extracted from the European Drug Emergencies Network (Euro-DEN) Plus database for all ED presentations with acute toxicity involving MDMA use, alone or in combination with other substances, between 1 January 2014 and 31 December 2017. Geographical distribution, time trends, patient demographics, clinical features, management and outcome were analysed.

Results: Out of 23,947 presentations, 2013 (8.4%) involved MDMA, used alone (88, 4.4%) or with other substances (1925, 95.6%). The proportion of MDMA presentations varied by country, from over 15% in France to less than 5% in Norway. For the 15 sentinel centres where data were available for all four years, MDMA-related presentations peaked in 2016 (10.4% 8.1% in 2015,  < 0.0001), thereafter decreasing in 2017 (8.2%,  = 0.0002). 1436 (71.3%) presentations involved males. Females were significantly younger than males (median 23 years, interquartile range, IQR, 20-27 years, median 25 years, IQR 21-30 years,  < 0.0001). Compared to presentations of acute toxicity with lone-use cocaine, presentations with lone-use MDMA occurred more frequently during the weekend (58.0% 43.9%,  = 0.02), were more frequently medically discharged directly from the ED (74.7% 62.4%,  = 0.03), and less frequently received sedation (43.5% 66.5%,  = 0.003).

Conclusions: This large multicentre series of MDMA presentations to EDs showed geographical variation and changes in time trends and in patient demographics. Triangulation with data from complementary sources including seizures, prevalence of use and wastewater analysis, will enable a greater understanding of the public health implications of MDMA use in Europe.
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February 2021

Emergency department presentations related to acute toxicity following recreational use of cannabis products in Switzerland.

Drug Alcohol Depend 2020 01 7;206:107726. Epub 2019 Nov 7.

Clinical Pharmacology and Toxicology, Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 15, 3010 Bern, Switzerland; Institute of Pharmacology, University of Bern, Freiburgstrasse 15, 3010, Bern, Switzerland. Electronic address:

Background: Concomitant use of cannabis and other psychoactive substances is common and it is often difficult to differentiate its acute effects from those of other substances. This study aimed to characterize the acute toxicity of cannabis with and without co-use of other substances.

Methods: Retrospective analysis of cases presenting at the emergency departments of three large hospitals in Switzerland due to acute toxicity related to cannabis recreational use.

Results: Among 717 attendances related to acute cannabis toxicity, 186 (26 %) were due to use of cannabis alone. The median patient age was 26 years (range 14-68), and 73 % were male. Commonly reported symptoms/signs in lone-cannabis cases included nausea/vomiting (26 %), palpitations (25 %), anxiety (23 %), and chest pain (15 %); there were no fatalities and most intoxications were of minor severity (61 %). Most patients (83 %) using cannabis alone were discharged from the emergency department, 8 % were referred to psychiatric, and two (1 %) to the intensive care; severe complications included psychosis (7 %), coma (6 %), and seizures (5 %) and one patient (<1 %) required intubation. Lone-cannabis patients presented more often with palpitations, anxiety, panic attacks, and chest pain than patients in the co-use group, whereas the latter presented more often with impaired consciousness, agitation, respiratory depression and hallucinations, and were more often admitted to psychiatric or intensive care.

Conclusion: Intoxication with cannabis alone was mostly associated with minor toxicity. Nevertheless, severe complications and cases requiring admission to intensive or psychiatric care were also reported, which indicates that intoxication with cannabis alone does not exclude considerable health risks.
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January 2020

Emergency department presentations related to abuse of prescription and over-the-counter drugs in Switzerland: time trends, sex and age distribution.

Swiss Med Wkly 2019 Jul 24;149:w20056. Epub 2019 Jul 24.

Clinical Pharmacology and Toxicology, Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland / Institute of Pharmacology, University of Bern, Switzerland.

Aims Of The Study: To analyse emergency department (ED) presentations related to acute medical problems after recreational use of prescription/over-the-counter (OTC) drugs in two major Swiss hospitals in order to identify the prevalence of specific drugs, vulnerable groups, time trends and local differences which could have major public health implications.

Methods: Retrospective analysis of cases presenting with signs/symptoms consistent with acute toxicity due to recreational use of prescription/OTC drugs from May 2012 to August 2017 at the ED of the University Hospital of Bern and from October 2013 to July 2017 at the ED of the University Hospital Basel. We investigated time trends, sex differences, patient characteristics and consumption patterns within three age groups (≥16 to <36 years; ≥36 to <56 years; ≥56 years).

Results: During the study period, 344 cases were included out of 1715 ED attendances due to acute drug toxicity and a total of 412,557 ED presentations. The use of prescription drugs in conjunction with illegal drugs was reported in nearly half the cases. The most frequently reported prescription drugs were benzodiazepines (64%, n = 220) and methadone (13%, n = 45). Forty-eight percent (n = 166) of all presentations occurred within the youngest age group. The analysis of time trends showed a significant increase in presentations in the youngest and the oldest groups in Basel (both p <0.05), while the trend remained stable over time in Bern for all age groups. While the number of presentations remained constant over time for men and women in Bern, a significant increase was found for the female cohort in Basel (p <0.05). Patients in all age groups presented with toxicities of predominantly minor severity.

Conclusion: The prescription/OTC drugs most frequently leading to ED presentations after recreational use were sedative substances. A large proportion of the patients belonged to the youngest age group. A significant increase in presentations was seen in the youngest and oldest age groups and within women in Basel. This information can be used to inform health care providers so that they can adapt their prevention and treatment strategies in their communities.
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July 2019

Perineural Invasion in Squamous Cell Carcinoma of the Oral Cavity: Histology, Tumor Stage, and Outcome.

Laryngoscope Investig Otolaryngol 2016 02 14;1(1):13-18. Epub 2016 Jan 14.

Department of Otorhinolaryngology Head and Neck Surgery.

Objectives/hypothesis: To analyze the impact of different types of perineural invasion (PNI) in squamous cell carcinoma (SCC) of the oral cavity on overall survival and recurrence rate, with a special focus on histologic subtypes and tumor stage.

Study Design: Retrospective case-control study with clinicopathological analysis.

Methods: Seventeen patients who received primary surgical treatment for SCC of the oral cavity with PNI were matched to a control group. In a histologic review, PNI was classified into subtypes according to an adapted Liebig classification. The term was used to describe tumor invasion into the nerve, whereas was used to describe circumferential growth around the nerve. Clinical charts were reviewed, and a Kaplan-Meier survival analysis was performed.

Results: The recurrence-free survival rates were 47.1% versus 80.4% (PNI vs. matched control group,  < 0.05), 60.0% versus 94.1% (PNI in stage I and II disease vs. matched control group,  < 0.05) and 41.7% versus 73.5% (PNI in stage III and IV disease vs. matched control group,  < 0.05). In most cases (n = 9) of PNI, both histologic subtypes (type A and type B) were present. Five cases exclusively showed type A, and three cases exclusively showed type B.

Conclusions: Perineural invasion in early disease oral carcinoma has a particularly high impact on survival. Both histologic subtypes showed a significantly worse recurrence-free survival rate when compared to the control group.

Level Of Evidence: 3.
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February 2016