Sudden Sensorineural Hearing Loss Following Immunization With BNT162b2 or mRNA-1273: A Danish Population-Based Cohort Study

OBJECTIVE

To compare the occurrence of sudden sensorineural hearing loss following immunization with BNT162b2 (Comirnaty®; Pfizer BioNTech) or mRNA-1273 (Spikevax®; Moderna) to the occurrence among unvaccinated individuals.

STUDY DESIGN

Cohort study.

SETTING

Nationwide Danish health care registers comprised all Danish residents living in Denmark on October 1, 2020, who were 18 years or older or turned 18 in 2021.

METHODS

We compared the occurrence of sudden sensorineural hearing loss following immunization with BNT162b2 (Comirnaty®; Pfizer BioNTech) or mRNA-1273 (Spikevax®; Moderna) (first, second, or third dose) against unvaccinated person time. Secondary outcomes were a first-ever hospital diagnosis of vestibular neuritis and a hearing examination, by an ear-nose-throat (ENT) specialist, followed by a prescription of moderate to high-dose prednisolone.

RESULTS

BNT162b2 or mRNA-1273 vaccine was not associated with an increased risk of receiving a discharge diagnosis of sudden sensorineural hearing loss (adjusted hazard ratio [HR]: 0.99, confidence interval [CI]: 0.59-1.64) or vestibular neuritis (adjusted HR: 0.94, CI: 0.69-1.24). We found a slightly increased risk (adjusted HR: 1.40, CI, 1.08-1.81) of initiating moderate to high-dose oral prednisolone following a visit to an ENT specialist within 21 days from receiving a messenger RNA (mRNA)-based Covid-19 vaccine.

CONCLUSION

Our findings do not suggest an increased risk of sudden sensorineural hearing loss or vestibular neuritis following mRNA-based COVID-19 vaccination. mRNA-Covid-19 vaccination may be associated with a small excess risk of a visit to an ENT specialist visit followed by a prescription of moderate to high doses of prednisolone.

Paternal preconception exposure to non-steroid anti-inflammatory drugs or opioids and adverse birth outcomes: A nationwide registry-based cohort study

BACKGROUND AND AIM

Paternal use of analgesics during the time of conception and adverse birth outcomes are poorly studied. We investigated the association between paternal exposure to non-steroid anti-inflammatory drugs and opioids within 3 months before the date of conception and the risk of adverse birth outcomes (preterm birth, small for gestational age, low Apgar score, and major congenital malformations).

METHODS

We used nationwide data from the Danish health registers. We included information on all singleton live births, and their fathers and mothers from 1997 to 2018. We created two exposed cohorts, children with preconception paternal exposure to (1) non-steroid anti-inflammatory drugs and (2) opioids. The unexposed cohort was children without preconception paternal exposure to non-steroid anti-inflammatory drugs or opioids, and we performed a sub-analysis against paternal use of acetaminophen (paracetamol). We used logistic regression models to estimate the odds ratios of adverse birth outcomes including 95% confidence intervals.

RESULTS

We identified 1,260,934 children, 45,667 children with paternal exposure to non-steroid anti-inflammatory drugs, 10,086 children with paternal exposure to opioids, and 1,205,181 unexposed children. The adjusted odds ratio for preterm birth was 1.08 (95% confidence interval, 1.03-1.13) after paternal exposure to non-steroid anti-inflammatory drugs and 1.21 (95% confidence interval, 1.08-1.35) after paternal exposure to opioids. The adjusted odds ratio for small for gestational age was 1.09 (95% confidence interval, 1.03-1.17) after paternal exposure to non-steroid anti-inflammatory drugs, and 1.03 (95% confidence interval, 0.88-1.21) after paternal exposure to opioids. We found null-associations for a low Apgar score and major congenital malformations. Estimates were attenuated when compared against paternal paracetamol exposure.

CONCLUSIONS

Overall, we found null-associations across the comparisons made. Weak associations were found for paternal exposure to non-steroid anti-inflammatory drugs or opioids and preterm birth and small for gestational age, but not with low Apgar score or major congenital malformation. All associations were attenuated when compared against an active comparator of paternal paracetamol exposure. The effect sizes were small and less likely to be of clinical relevance.

Use of opioids among pregnant women 1997-2016: A Danish drug utilization study

OBJECTIVE

Use of opioids in pregnancy is of concern yet little is known on opioid prescription patterns in Denmark. The aim of this drug utilization study was to describe prescription patterns for opioids during pregnancy in Denmark from 1997 to 2016.

STUDY DESIGN

Using the nationwide health care registers, we obtained information on all women with a registered pregnancy in the period 1 January 1997 to 31 December 2016. Opioids were grouped in four: opioids (N02A except codeines), opioid dependency medications (N07BC), cough medications (R05DA except codeines), and codeines (N02AJ06, N02AJ07, N02BA75, and R05DA04). We used logistic regression analyses to identify factors associated with opioid use in pregnancy and cumulative oral morphine equivalent (OMEQ) to estimate volume of use in pregnancy.

RESULTS

Prescription patterns were similar for women with live births, non-live births, and terminations. Total use of opioids among women with live born deliveries remained stable at 19.8 per 1000 pregnancies from 1997 to 2016. Codeine use declined from 2008 onwards, while use of other opioids increased from 2007 onwards. This was dominated by a threefold increase in tramadol use (2.0-7.6 per 1000 pregnancies with live births). Codeine was the most used opioid, followed by tramadol and codeine combined with paracetamol. The number of women, who used opioids before pregnancy and continued into their pregnancy, was reduced as the pregnancy progressed. The cumulative oral morphine equivalent during pregnancy was stable until 2007, after which, use prior to pregnancy and during the first two trimesters increased. The odds ratios for opioid use were higher in pregnancies of women of lower socioeconomic status or older age. For live births, odds ratios for opioid use in pregnancy were higher among women with obesity or smoking.

CONCLUSIONS

Overall use of opioids was stable from 2007 to 2016. This covers a decline in the use of codeine, but a 3-fold increase in tramadol. The number of pregnant women who continued use throughout pregnancy decreased, while OMEQ among persistent users increased. The real-world data suggest an unmet need of specific focus in local Danish Outpatient Clinics and Multidisciplinary Pain Centers both pre-conceptionally and during pregnancy.

Serotonin Syndrome

BACKGROUND

Serotonin syndrome is a potentially life-threatening syndrome with manifestations spanning from mild adverse effects to life-threatening toxicity. The syndrome is caused by overstimulation of serotonin receptors by serotonergic drugs. Since the use of serotonergic drugs is increasing, primarily due to the widespread use of selective serotonin reuptake inhibitors, cases of serotonin syndrome have likely seen a parallel increase. The true incidence of serotonin syndrome remains unknown due to its diffuse clinical presentation.

OBJECTIVES

This review aims to provide a clinically focused overview of serotonin syndrome, covering its pathophysiology, epidemiology, clinical manifestations, diagnostic criteria, differential diagnosis, and treatment as well as classifying serotonergic drugs and their mechanism of action. The pharmacological context is emphasized, as it is crucial for detection and management of serotonin syndrome.

METHODS

Focused review based on a literature search using the PubMed database.

FINDINGS AND CONCLUSION

Serotonin syndrome can occur through therapeutic use or overdose of a single serotonergic drug, or as a drug interaction between two or more serotonergic drugs. Central clinical features consist of neuromuscular excitation, autonomic dysfunction and altered mental status, occurring in a patient undergoing new or altered serotonergic therapy. Early clinically recognition and treatment are crucial to prevent significant morbidity.

Expert consensus on neurodevelopmental outcomes in pregnancy pharmacovigilance studies

Background: Exposure in utero to certain medications can disrupt processes of fetal development, including brain development, leading to a continuum of neurodevelopmental difficulties. Recognizing the deficiency of neurodevelopmental investigations within pregnancy pharmacovigilance, an international Neurodevelopmental Expert Working Group was convened to achieve consensus regarding the core neurodevelopmental outcomes, optimization of methodological approaches and barriers to conducting pregnancy pharmacovigilance studies with neurodevelopmental outcomes. Methods: A modified Delphi study was undertaken based on stakeholder and expert input. Stakeholders (patient, pharmaceutical, academic and regulatory) were invited to define topics, pertaining to neurodevelopmental investigations in medication-exposed pregnancies. Experts were identified for their experience regarding neurodevelopmental outcomes following medicinal, substances of misuse or environmental exposures in utero. Two questionnaire rounds and a virtual discussion meeting were used to explore expert opinion on the topics identified by the stakeholders. Results: Twenty-five experts, from 13 countries and professionally diverse backgrounds took part in the development of 11 recommendations. The recommendations focus on the importance of neurodevelopment as a core feature of pregnancy pharmacovigilance, the timing of study initiation and a core set of distinct but interrelated neurodevelopmental skills or diagnoses which require investigation. Studies should start in infancy with an extended period of investigation into adolescence, with more frequent sampling during rapid periods of development. Additionally, recommendations are made regarding optimal approach to neurodevelopmental outcome measurement, comparator groups, exposure factors, a core set of confounding and mediating variables, attrition, reporting of results and the required improvements in funding for potential later emerging effects. Different study designs will be required depending on the specific neurodevelopmental outcome type under investigation and whether the medicine in question is newly approved or already in widespread use. Conclusion: An improved focus on neurodevelopmental outcomes is required within pregnancy pharmacovigilance. These expert recommendations should be met across a complementary set of studies which converge to form a comprehensive set of evidence regarding neurodevelopmental outcomes in pregnancy pharmacovigilance.

Flucloxacillin is a weak inducer of CYP3A4 in healthy adults and 3D spheroid of primary human hepatocytes

Flucloxacillin is a widely used antibiotic. It is an agonist to the nuclear receptor Pregnane X Receptor (PXR) that regulates the expression of cytochrome P450 (CYP) enzymes. Treatment with flucloxacillin reduces warfarin efficacy and plasma concentrations of tacrolimus, voriconazole, and repaglinide. We conducted a translational study to investigate if flucloxacillin induces CYP enzymes. We also investigated if flucloxacillin induces its own metabolism as an autoinducer. We performed a randomized, unblinded, two-period, cross-over, clinical pharmacokinetic cocktail study. Twelve healthy adults completed the study. They ingested 1 g flucloxacillin three times daily for 31 days, and we assessed the full pharmacokinetics of the Basel cocktail drugs on days 0, 10, and 28, and plasma concentrations of flucloxacillin on days 0, 9, and 27. 3D spheroid of primary human hepatocytes (PHH) were exposed to flucloxacillin (concentration range: 0.15-250 μM) for 96 hours. Induction of mRNA expression, protein abundance, and enzyme activity of CYP enzymes were assessed. Flucloxacillin treatment reduced the metabolic ratio of midazolam (CYP3A4), (geometric mean ratio (GMR) 10 days (95% confidence interval (CI)): 0.75 (0.64-0.89)) and (GMR 28 days (95% CI): 0.72 (0.62-0.85)). Plasma concentrations of flucloxacillin did not change during 27 days of treatment. Flucloxacillin caused concentration-dependent induction of CYP3A4 and CYP2B6 (mRNA, protein, and activity), CYP2C9 (mRNA and protein), CYP2C19 (mRNA and activity), and CYP2D6 (activity) in 3D spheroid PHH. In conclusion, flucloxacillin is a weak inducer of CYP3A4, which may lead to clinically relevant drug-drug interactions for some narrow therapeutic range drugs that are substrates of CYP3A4.

An analysis of the level of evidence behind treatments recommended by the Danish Medicines Council

OBJECTIVES

We aimed to investigate the quality of evidence and the expected added clinical value of treatments recommended by the Danish Medicines Council (DMC).

STUDY DESIGN

This was an observational study.

METHODS

The DMC prepares reports on drugs considered for possible new standard treatments in Danish hospitals. These reports evaluate the available evidence on efficacy and safety. The quality of evidence is systematically rated by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria, and estimates of added clinical value are presented. The recommendations take into account expected economic implications of new treatments. The publicly available reports up until December 29, 2021, were downloaded from the DMC Web page. Reports on drugs marked "recommended" were included. Data on quality of evidence, expected clinical value, and economic implications were imputed in a Microsoft Excel spreadsheet.

RESULTS

Seventy-nine reports were included in the analysis. In 79% of these, the quality of evidence was rated low (24%) or very low (55%), whereas no recommendations were based on evidence rated as high quality. Three (5%) of recommended treatments were expected to add large clinical value.

CONCLUSIONS

Most recommendations by the DMC are based on evidence formally rated as low or very low quality by GRADE, and no recommendations were based on evidence rated as high quality. The added clinical value of the treatments was often not documented and rarely large. Continued attention to improve the clinical evidence behind national recommendations is necessary.

Abstract P5-03-11: The impact of single nucleotide polymorphisms on return-to-work after taxane-based chemotherapy in breast cancer

Background Return-to-work (RTW) after breast cancer may be challenging for breast cancer survivors, especially those who experience adverse effects. Neuropathies are common adverse effect of taxane-based chemotherapy. Single nucleotide polymorphisms (SNPs) in genes related to taxane metabolism and transport, neural function, and neural- or DNA-repair may influence the risk of taxane-induced adverse effects, potentially impacting patient recovery and RTW. We examined the association of such SNPs with RTW in premenopausal breast cancer survivors. Methods We used Denmark’s nationwide population-based health registries to ascertain data on premenopausal women aged 18‒55 years diagnosed with non‒distant metastatic breast cancer during 2007‒2011, who were candidates for adjuvant combination chemotherapy including cyclophosphamide and docetaxel. Only women employed at diagnosis were included. We collected archived tumor tissue from nationwide pathology departments and genotyped 26 SNPs in 20 genes using TaqMan assays. For each SNP, we categorized the women as wildtype, homozygote or heterozygote. Follow-up continued from the date of primary surgery to the first of RTW (defined as 4 consecutive weeks of work), recurrence, maternity leave/childbirth, other malignancy, retirement, death, emigration or 25th September 2017. We computed the cumulative incidence of RTW and used Cox regression models to calculate unadjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of RTW. Results We included 1,963 women. Women who were homozygotes for the phase 1 metabolizer CYP3A5 rs776746 (n=15) had lower cumulative incidence of RTW than wildtypes (n=1,600) and heterozygotes (n=249), 7%, 25% and 17% at six months, 57%, 87% and 88% at two years, and 82%, 94% and 94% at end of follow-up, respectively. Compared with wildtypes, CYP3A5 rs776746 homozygotes had delayed RTW throughout follow-up (HR 0-10 years: 0.48, 95% CI: 0.26, 0.86). No other SNPs were associated with RTW. Conclusions Among 26 SNPs, CYP3A5 rs776746 was associated with delayed RTW after breast cancer among premenopausal women. Our findings may help identify women at risk of a poor clinical course, who may benefit from enhanced supportive care during treatment and follow-up.

Citation Format: Cathrine Hjorth, Per Damkier, Tore B. Stage, Søren Feddersen, Stephen Hamilton-Dutoit, Bent Ejlertsen, Timothy L. Lash, Henrik Bøggild, Henrik Sørensen, Deirdre Cronin-Fenton. The impact of single nucleotide polymorphisms on return-to-work after taxane-based chemotherapy in breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-03-11.

The impact of single nucleotide polymorphisms on return-to-work after taxane-based chemotherapy in breast cancer

PURPOSE

Breast cancer treatment is associated with adverse effects, which may delay return-to-work. Single nucleotide polymorphisms (SNPs) may influence the risk and severity of treatment toxicities, which in turn could delay return-to-work. We examined the association of 26 SNPs with return-to-work in premenopausal women with breast cancer.

METHODS

Using Danish registries, we identified premenopausal women diagnosed with non-distant metastatic breast cancer during 2007‒2011, assigned adjuvant combination chemotherapy including cyclophosphamide and docetaxel. We genotyped 26 SNPs in 20 genes (ABCB1, ABCC2, ABCG2, CYP1A1, CYP1B1, CYP3A, CYP3A4, CYP3A5, GSTP1, SLCO1B1, SLCO1B3, ARHGEF10, EPHA4, EPHA5, EPHA6, EPHA8, ERCC1, ERCC2, FGD4 and TRPV1) using TaqMan assays. We computed the cumulative incidence of return-to-work (defined as 4 consecutive weeks of work) up to 10 years after surgery, treating death and retirement as competing events and fitted cause-specific Cox regression models to estimate crude hazard ratios (HRs) and 95% confidence intervals (CIs) of return-to-work. We also examined stable labor market attachment (defined as 12 consecutive weeks of work).

RESULTS

We included 1,964 women. No associations were found for 25 SNPs. The cumulative incidence of return-to-work varied by CYP3A5 rs776746 genotype. From 6 months to 10 years after surgery, return-to-work increased from 25 to 94% in wildtypes (n = 1600), from 17 to 94% in heterozygotes (n = 249), and from 7 to 82% in homozygotes (n = 15). The HR showed delayed return-to-work in CYP3A5 rs776746 homozygotes throughout follow-up (0.48, 95% CI 0.26, 0.86), compared with wildtypes. Estimates were similar for stable labor market attachment.

CONCLUSION

Overall, the SNPs examined in the study did not influence return-to-work or stable labor market attachment after breast cancer in premenopausal women. Our findings did suggest that the outcomes were delayed in homozygote carriers of CYP3A5 rs776746, though the number of homozygotes was low.

Implementation and clinical benefit of DPYD genotyping in a Danish cancer population

BACKGROUND

In 2020, the European Medicines Agency recommended testing patients for dihydropyrimidine dehydrogenase (DPD) deficiency before systemic treatment with fluoropyrimidines (FP). DPD activity testing identifies patients at elevated risk of severe FP-related toxicity (FP-TOX). The two most used methods for DPD testing are DPYD genotyping and DPD phenotyping (plasma uracil concentration). The primary objective of this study was to compare the overall frequency of overall grade ≥3 FP-TOX before and after the implementation of DPYD genotyping.

PATIENTS AND METHODS

Two hundred thirty Danish, primarily gastrointestinal cancer patients, were DPYD-genotyped before their first dose of FP, and blood was sampled for post hoc assessment of P-uracil. The initial dose was reduced for variant carriers. Grade ≥3 FP-TOX was registered after the first three treatment cycles of FP. The frequency of toxicity was compared to a historical cohort of 492 patients with post hoc determined DPYD genotype from a biobank.

RESULTS

The frequency of overall grade ≥3 FP-TOX was 27% in the DPYD genotype-guided group compared to 24% in the historical cohort. In DPYD variant carriers, DPYD genotyping reduced the frequency of FP-related hospitalization from 19% to 0%. In the control group, 4.8% of DPYD variant carriers died due to FP-TOX compared to 0% in the group receiving DPYD genotype-guided dosing of FP. In the intervention group, wild-type patients with uracil ≥16 ng/ml had a higher frequency of FP-TOX than wild-type patients with uracil <16 ng/ml (55% versus 28%).

CONCLUSIONS

We found no population-level benefit of DPYD genotyping when comparing the risk of grade ≥3 FP-TOX before and after clinical implementation. We observed no deaths or FP-related hospitalizations in patients whose FP treatment was guided by a variant DPYD genotype. The use of DPD phenotyping may add valuable information in DPYD wild-type patients.

A critical appraisal of controlled studies investigating malformation risks following pregabalin use in early pregnancy

In March 2022, the Summary of Product Characteristics for the Lyrica brand of pregabalin was updated with warnings regarding malformation risks. This literature review and critical appraisal aims to explore whether these Summary of Product Characteristics updates are justified and provide clarity on the risk-benefit balance for pregabalin use in early pregnancy. A literature review was conducted in May 2022 to identify English language comparative studies of any design providing data about first trimester maternal pregabalin use and malformation risk. Five observational comparative cohort studies using data from 9 distinct datasets were located. Collectively these studies described at least 5300 unique pregabalin exposed pregnancies, with 4900 exposed in at least the first trimester. Three studies investigated overall major malformation risks, and 4 investigated specific malformation risks. The available evidence was found to be conflicting and generally of low quality, probably influenced by bias and data confounding, with no clear pattern of specific malformations observed. Findings from the largest study suggested absolute risks of major malformation of 4.8-5.6%, relative to a background risk of approximately 4%. Due to study methodology limitations, the available data were judged to only provide low quality evidence suggestive of a possible and unconfirmed small increased risk that cannot be solely attributed to foetal pregabalin exposure. This literature review and critical appraisal indicates that the Lyrica product literature updates are insufficiently substantiated and could result in confusion and misinformed clinical risk-benefit decision making.

The risk of fragility fractures following initiation of gabapentin and pregabalin-A Danish, nationwide, high-dimensional propensity score-matched cohort study

Gabapentin and pregabalin have been associated with an increased risk of fragility fractures. Due to differences in pharmacokinetics, we aimed to assess the fracture-risk difference between the two medicines. We performed a Danish nationwide new user, high-dimensional propensity score-matched cohort study to assess the 90-day risk of fragility fractures among adults, from January 1996 to December 2018. We applied a high-dimensional propensity score to match new users of gabapentin with new users of pregabalin in a 1:1 intention-to-treat approach. Hazard ratios (HRs), incidence rates (IRs) and incidence rate difference (IRD) were obtained. We identified 388 236 eligible patients of which 294 223 and 98 869 initiated gabapentin and pregabalin, respectively. We included 48 272 matched pairs for further analysis. The mean age was 56 (IQR 44-69) years, and the average follow-up was approximately 11 500 person-years (PY). The IRs of fragility fractures were 23.7 (95%CI 21.0-26.7) and 23.2 (95%CI 20.5-26.2) per 1000 PY for gabapentin and pregabalin-exposed patients, respectively. This yielded an HR of 1.02 (95%CI 0.86-1.21) when using gabapentin as the intervention drug and pregabalin as the reference drug. The IRD was estimated to 0.5 PY (95%CI -3.5-4.5). In conclusion, short-term risk of fragility fractures among gabapentin initiators was not different compared to those initiating pregabalin.

Adverse Birth and Child Outcomes in Children Fathered by Men Treated with Antidiabetics Prior to Conception: A Nationwide Cohort Study

BACKGROUND

The safety of fathers' use of antidiabetic drugs in terms of child outcomes is an important clinical question. We aimed to assess the risk of adverse birth and early childhood outcomes after fathers' use of antidiabetics prior to conception.

METHODS

A nationwide cohort study based on Danish health registries. The study comprised all live born singleton children in Denmark (1997 through 2018). Children were categorized according to fathers' filled prescriptions for antidiabetic drugs three months prior to conception. Exposed cohorts: children born after paternal use of insulin or non-insulin anti-hyperglycemic agents. The unexposed constituted children born by fathers not treated with antidiabetics prior to conception. We examined adverse birth outcomes (preterm birth, small for gestational age (SGA)), and adverse childhood outcomes in the first year of life (major congenital malformations (MCMs), and infections diagnosed at a hospital).

RESULTS

A total of 1,318,684 children were included. In all, 5527 children were born after paternal use of insulin, 2121 after use of non-insulin anti-hyperglycemic agents, and 1,311,036 were unexposed. After fathers' use of insulin we did not find increased risk of adverse outcomes. After fathers' use of metformin, the adjusted OR of MCMs was 1.40 (95% CI 1.11-1.76). After fathers' use of sulfonylureas, the adjusted OR of SGA was 1.80 (95% CI 1.11-2.93), and for child gastrointestinal infections the adjusted HR was 1.76 (95% CI 1.04-2.99).

CONCLUSIONS

Fathers' use of insulin was reassuring. Metformin and sulfonylureas were associated with selected adverse outcomes. Our findings suggest an additional 14 MCMs per 1000 fathers exposed to metformin prior to conception. As there is no meaningful supporting biological rationale, these findings should be confirmed in a different population prior to clinical consequences being drawn.

Statin use before and after the KDIGO Lipids in chronic kidney disease guideline: A population-based interrupted time series analysis

In November 2013, the Kidney Disease: Improving Global Outcomes Clinical Practice Guideline for Lipid Management in Chronic Kidney Disease was published, recommending statins for all individuals 50 years or older with an estimated glomerular filtration rate below 60 ml/min/1.73 m² to lower the risk of major cardiovascular events. We quantified the prevalence of statin use among the target population before and after the guideline publication in a large Danish cohort of individuals with an estimated glomerular filtration rate below 60 ml/min/1.73 m² , to investigate the effect of the guideline, but found no difference in the prevalence of statin use prior to and after the guideline publication.

DPYD genotyping and dihydropyrimidine dehydrogenase (DPD) phenotyping in clinical oncology. A clinically focused minireview

BACKGROUND

In clinical oncology, systemic 5-fluorouracil (5-FU) and its oral pro-drugs are used to treat a broad group of solid tumours. Patients with dihydropyrimidine dehydrogenase (DPD) enzyme deficiency are at elevated risk of toxicity if treated with standard doses of 5-FU. DPYD genotyping and measurements of plasma uracil concentration (DPD phenotyping) can be applied as tests for DPD deficiency. In April 2020, the European Medicines Agency recommended pre-treatment DPD testing to reduce the risk of 5-FU-related toxicity.

OBJECTIVES

The objective of this study is to present the current evidence for DPD testing in routine oncological practice.

METHODS

Two systematic literature searches were performed following the PRISMA guidelines. We identified studies examining the possible benefit of DPYD genotyping or DPD phenotyping on the toxicity risk.

FINDINGS

Nine and 12 studies met the criteria for using DPYD genotyping and DPD phenotyping, respectively.

CONCLUSIONS

The evidence supporting either DPYD genotyping or DPD phenotyping as pre-treatment tests to reduce 5-FU toxicity is poor. Further evidence is still needed to fully understand and guide clinicians to dose by DPD activity.

Balsalazide Exposure During the Development of Fertilizing Sperm May Be Associated With Offspring Birth Defects

We report an association between balsalazide exposure during the development of fertilizing sperm and birth defects in offspring. Exposed offspring were approximately 8 times more likely to have a birth defect. There were no pre-existing reasons to suspect such a relationship, which should be confirmed in other data.

Changing characteristics over time of individuals receiving COVID-19 vaccines in Denmark: A population-based descriptive study of vaccine uptake

AIMS

The Danish authorities implemented a differential rollout of the COVID-19 vaccines where individuals at high risk of COVID-19 were prioritized. We describe the temporal uptake and characteristics of COVID-19 vaccine recipients in Denmark.

METHODS

Using nationwide healthcare registries, we identified all Danish residents ⩾5 years of age who received at least one dose of a COVID-19 vaccine from 27 December 2020-29 January 2022. We charted the daily number of newly vaccinated individuals and the cumulative vaccine coverage over time, stratified by vaccine type, age groups and vaccination priority groups, and described characteristics of vaccine recipients during two-month-intervals and in vaccination priority groups.

RESULTS

By 29 January 2022, 88%, 86% and 64% of Danish residents ⩾5 years (n=5,562,008) had received a first, second and third dose, respectively, of a COVID-19 vaccine, most commonly the BNT162b2 vaccine (84%). Uptake ranged from 48% in 5-11-year-olds to 98% in 65-74-year-olds. Individuals vaccinated before June 2021 were older (median age 61-70 years vs 10-35 years in later periods) and had more comorbidities such as hypertension (22-28% vs 0.77-2.8% in later periods), chronic lung disease (9.4-15% vs 3.7-4.6% in later periods) and diabetes (9.3-12% vs 0.91-2.4% in later periods).

CONCLUSIONS

We document substantial changes over time in, for example, age, sex and medical history of COVID-19 vaccine recipients. Though these results are related to the differential vaccine rollout in Denmark, similar findings are probable in other countries and should be considered when designing and interpreting studies on the effectiveness and safety of COVID-19 vaccines.

Use of hypnotic drugs among Scandinavian children, adolescents, and young adults

Introduction

Hypnotic drug use in children and adolescents is widely debated.

Objectives

To describe use of hypnotic drugs (melatonin, z-drugs and sedating antihistamines) among 5-24-year-old Scandinavians during 2012 to 2018.

Methods

Aggregate-level data from public data sources in Sweden, Norway and Denmark. We calculated annual prevalence (users/1000 inhabitants) stratified by sex, age group and country. Quantity of use (Defined Daily Dose (DDD)/user/day) was estimated for Norway and Denmark.

Results

Melatonin was most frequently used, with an increase from 2012 to 2018 in all countries. Sweden presented the highest rise (7 to 25/1,000) compared to Denmark (6 to 12/1,000) and Norway (10 to 20/1,000). The increase was strongest for females and 15-24-year-olds. Melatonin use was twice as common for males under age 15 years, and slightly more common for females thereafter. The annual prevalence of sedating antihistamine use doubled from 7 to 13/1,000 in Sweden, whereas it was more stable in Norway and Denmark, reaching 8/1,000 and 3/1,000, respectively. Z-drug use decreased in all countries, lowering to 4/1,000 in Sweden and Norway in 2018 and 2/1,000 in Denmark. The quantity of hypnotic use in Norway and Denmark was 1 DDD/user/day for melatonin, as compared to 0.1-0.3 for z-drugs and antihistamines.

Conclusions

There is an increasing use of melatonin and sedating antihistamines among Scandinavian children, adolescents and young adults. The increase is more pronounced in Sweden compared to Norway and Denmark. This Scandinavian discrepancy could reflect variation in frequency of sleep problems or national variation in clinical practice or health care access.

Disclosure

No significant relationships.

Risk of Appendicitis After mRNA COVID-19 Vaccination in a Danish Population

This cohort study used data from Danish registers to assess whether recipients of mRNA COVID-19 vaccines had a higher risk of appendicitis after receiving the shot compared with individuals who did not receive the vaccine.

Lithium and the risk of chronic kidney disease: A population-based case-control study

The association between lithium use and chronic kidney disease (CKD) needs further evaluation. We aimed to investigate this association using Danish nationwide healthcare registers and routinely collected plasma creatinine measurements from the Funen Laboratory Cohort. We conducted a case–control study nested within the population of Funen, 2001–2015. Incident cases of CKD (estimated glomerular filtration rate <60 ml/min/1.73m²; n = 21 432) were matched with four CKD‐free controls on age, sex and calendar time (n = 85 532). We estimated odds ratios (OR) for the association between lithium exposure and CKD using conditional logistic regression models, adjusted for known risk factors for CKD. Ever‐use of lithium was associated with an increased risk of CKD (adjusted OR [aOR]: 1.57; 95% confidence interval [CI]: 1.33–1.85). A stronger association was seen with current use of lithium (aOR: 1.92; 95%CI: 1.58–2.33) and long‐term use of lithium (>10 years: aOR: 3.02; 95%CI: 2.00–4.56). Furthermore, we found evidence of a dose–response relationship between cumulative dose of lithium and the risk of CKD. In conclusion, the use of lithium, especially long‐term, is associated with an increased risk of CKD, although the extent to which detection bias and confounding by indication contribute to the association is unclear. Monitoring of kidney function in lithium users remains mandatory to identify individuals in which switching to alternative medications should be considered.

Development and Validation of a Nordic Multimorbidity Index Based on Hospital Diagnoses and Filled Prescriptions

Purpose

To develop the Nordic Multimorbidity Index (NMI), a multimorbidity measure specifically suited to the Nordic health and administrative registry data based on current diagnosis, treatment, and coding practices.

Methods

The NMI was developed to predict 5-year mortality in a population-based cohort of randomly sampled Danish residents aged ≥40 years (n = 425,087) followed from 2013 to 2018. Included predictors were selected from hospital diagnoses and filled drug prescriptions based on a combination of subject matter knowledge and a data-driven approach using backwards elimination. The performance of the NMI was assessed in a temporal validation cohort of Danish residents followed from 2007 to 2012 and in six cohorts of new users of selected drugs. The discriminative performance of the NMI, Charlson Comorbidity Index (CCI) and the Elixhauser Comorbidity Index (ECI) was assessed using the c-statistic from logistic regression models with 5-year mortality as dependent variable and the multimorbidity index score, age, and sex as independent variables.

Results

The NMI included 50 predictors. In the temporal validation cohort, the c-statistic of the NMI (0.887, 95% CI 0.883–0.890) exceeded that of the CCI (0.871, 95% CI 0.868–0.874) and ECI (0.866, 95% CI 0.863–0.870). In all new user cohorts, the NMI outperformed the other indices with c-statistics ranging from 0.781 (95% CI 0.779–0.784) to 0.838 (95% CI 0.834–0.842).

Conclusion

The NMI predicted 5-year mortality in a general Danish population and six cohorts of new users of selected drugs and was superior to the CCI and ECI. The NMI could be preferred over these indices to quantify the level of multimorbidity for, eg, descriptive purposes or confounding control. The NMI should be validated in other patient populations and other Nordic countries.

Medication-Associated Phthalate Exposure and Childhood Cancer Incidence

BACKGROUND

Human phthalate exposure is widespread through contact with myriad consumer products. Exposure is particularly high through medications formulated with phthalates. Phthalates disrupt normal endocrine signaling and are associated with reproductive outcomes and incidence of some cancers. We measured associations between gestational and childhood medication-associated phthalate exposures and the incidence of childhood cancers.

METHODS

We identified all live births in Denmark between 1997 and 2017, including both children and birth mothers. Using drug ingredient data merged with the Danish National Prescription Registry, we measured phthalate exposure through filled prescriptions for mothers during pregnancy (gestational exposure) and for children from birth until age 19 years (childhood exposure). Incident childhood cancers were ascertained from the Danish Cancer Registry, and associations were estimated with Cox regression models.

RESULTS

Among 1 278 685 children, there were 2027 childhood cancer cases diagnosed over 13.1 million person-years of follow-up. Childhood phthalate exposure was strongly associated with incidence of osteosarcoma (hazard ratio [HR] = 2.78, 95% confidence interval [CI] = 1.63 to 4.75). We also observed a positive association with incidence of lymphoma (HR = 2.07, 95% CI = 1.36 to 3.14), driven by associations with Hodgkin and non-Hodgkin lymphoma but not Burkitt lymphoma. Associations were apparent only for exposure to low-molecular phthalates, which have purportedly greater biological activity.

CONCLUSIONS

Childhood phthalate exposure was associated with incidence of osteosarcoma and lymphoma before age 19 years. Lingering questions include which specific phthalate(s) are responsible for these associations, by what mechanisms they occur, and to what extent childhood cancer cases could be avoided by reducing or eliminating the phthalate content of medications and other consumer products.

Abstract P3-12-22: Socioeconomic position and prognosis in premenopausal breast cancer: A population-based cohort study in Denmark

Background: To investigate how socioeconomic position (SEP) influences the effectiveness of cancer-directed treatment in premenopausal breast cancer patients in terms of breast cancer recurrence and mortality.Methods: Our cohort included all premenopausal women aged 18-55 years diagnosed with non-metastatic breast cancer and prescribed docetaxel-based chemotherapy in Denmark during 2007-2011. Population-based administrative registries provided data on SEP: marital status (married including registered partnership or single including divorced or widowed), cohabitation (cohabiting or living alone), education (low, intermediate or high), income (low, medium or high), and employment status (employed, unemployed or health-related absenteeism). For each SEP measure, we computed incidence rates, cumulative incidence proportions (CIPs) and used Poisson regression to compute incidence rate ratios and 95% confidence intervals (95% CIs) of recurrence and death. We stratified on ER status/tamoxifen to evaluate interaction.Results: Our cohort included 2,616 women; 286 (CIP: 13%) experienced recurrence and 223 (CIP: 11%) died during follow-up (median 6.6 and 7.2 years, respectively). Single women had both increased risks of recurrence (IRR: 1.45, 95% CI: 1.11-1.89) and mortality (IRR: 1.83, 95% CI: 1.32-2.52). Furthermore, we observed increased mortality in women with low education (IRR: 1.49, 95% CI: 0.95-2.33), low income (IRR: 1.37, 95% CI: 0.83-2.28), unemployment (IRR: 1.61, 95% CI: 0.83-3.13) or health-related work absenteeism (IRR: 1.80, 95% CI: 1.14-2.82), but smaller or no increased risk of recurrence. These findings were especially evident among women with ER+ tumors prescribed tamoxifen.Conclusions: Low SEP in premenopausal women with non-metastatic breast cancer was associated with increased mortality, but not always recurrence. This suggests underdetection of recurrences in certain groups. Poor prognosis in women with low SEP, especially single women, may partly be explained by tamoxifen adherence.

Citation Format: Cathrine Hjorth, Per Damkier, Bent Ejlertsen, Timothy L Lash, Henrik T Sørensen, Deirdre Cronin-Fenton. Socioeconomic position and prognosis in premenopausal breast cancer: A population-based cohort study in Denmark [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-12-22.

Abstract P3-13-06: Single nucleotide polymorphisms and mortality after docetaxel-based chemotherapy in premenopausal breast cancer: A population-based cohort study in Denmark

Background Taxane-based chemotherapy is first line treatment in various cancers, including premenopausal breast cancer, but the inter-individual effectiveness is unpredictable. Differences in expression and activity of docetaxel-metabolizing enzymes and transporters (DMETs) may modify docetaxel effectiveness. Although reported data are inconsistent, some findings suggests that variant alleles that reduce the function of 1) SLC-transporters reduce drug influx into hepatocytes; 2) CYP-450 enzymes hamper drug metabolism; and 3) ABC-transporters decrease docetaxel clearance. The net effect is hypothesized to be increased docetaxel exposure and effectiveness. In contrast, GSTP1 variants have been associated with poorer docetaxel effectiveness. We investigated whether single nucleotide polymorphisms (SNPs) in drug metabolizing enzymes and transporters were associated with mortality in premenopausal breast cancer patients. Materials and methods Using the Danish Breast Cancer Group (DBCG) clinical database, we identified data on premenopausal women aged 18–55 years, diagnosed with non–metastatic breast cancer during 2007–2011. All women were recommended epirubicin, cyclophosphamide and docetaxel-based adjuvant chemotherapy, and tamoxifen if the disease was estrogen receptor (ER) positive. From DBCG and other Danish administrative and medical registries we retrieve data on death, emigration, and tumor characteristics. We collected archived formalin-fixed paraffin-embedded primary tumor tissue from Danish pathology departments. We genotyped 17 candidate SNPs using TaqMan SNP genotyping assays and, for each SNP, categorized the women as having two normal alleles (wildtype) or at least one variant allele. We followed the women from six months after breast cancer diagnosis until death, emigration or 30th June 2019, whichever came first. Comparing variant carriers with wildtype, we computed cumulative incidence proportions (CIPs) and used Poisson regression models to calculate unadjusted incidence rate ratios (IRRs) and associated 95% confidence intervals (CIs) of all–cause mortality. We stratified by ER status to evaluate interaction. Analyses were repeated for breast cancer specific mortality. Results Our cohort included 2,262 women. During follow–up (median 9.6 years, interquartile range: 8.4–11.0), 250 women died (CIP: 14%); 219 due to breast cancer (CIP: 11%). Genotyping was successful for ≥95% of the study cohort, with exception of two SNPs, which were excluded from analyses. We detected decreased mortality in variant carriers of SLCO1B1 rs2306283 (IRR: 0.75, 95% CI 0.58–0.97), and ABCB1 rs1128503 (IRR: 0.81, 95% CI: 0.63–1.05), ABCB1 rs2032582 (IRR: 0.80, 95% CI: 0.62–1.04) and ABCC2 rs12762549 (IRR: 0.80, 95% CI: 0.62–1.04). In contrast, mortality was increased in carriers of GSTP1 rs1138272 (IRR: 1.28, 95% CI: 0.93–1.76) and, unexpectedly, in carriers of CYP3A rs10273424 (IRR: 1.36, 95% CI: 0.99–1.86) variant carriers. Sensitivity analyses yielded similar findings. ER status did not modify the associations. Conclusions In this study, mortality may be associated with SNPs in ABCB1, ABCC2, SLCO1B1, CYP3A and GSTP1 in premenopausal women with non-metastatic breast cancer receiving docetaxel. The mechanisms underlying our findings remains unclear but may be related to docetaxel pharmacokinetics.

Citation Format: Cathrine F Hjorth, Per Damkier, Tore B Stage, Søren Feddersen, Bent Ejlertsen, Timothy L Lash, Stephen Hamilton-Dutoit, Thomas P Ahern, Mikael Rørth, Henrik T Sørensen, Deirdre Cronin-Fenton. Single nucleotide polymorphisms and mortality after docetaxel-based chemotherapy in premenopausal breast cancer: A population-based cohort study in Denmark [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-13-06.

Physician-led in-hospital multidisciplinary team conferences with multiple medical specialities present - A scoping review

INTRODUCTION

Multidisciplinary Team Conferences (MDTs) are complex interventions in the modern healthcare system and they promote a model of coordinated patient care and management. However, MDTs within chronic diseases are poorly defined. Therefore, the aim of this scoping review was to summarise the current literature on physician-led in-hospital MDTs in chronic non-malignant diseases.

METHOD

Following the PRISMA-ScR guideline for scoping reviews, a search on MDT interventions in adult patients, with three or more medical specialties represented, was performed.

RESULTS

We identified 2790 studies, from which 8 studies were included. The majority of studies were non-randomised and focused on a single disease entity such as infective endocarditis, atrial fibrillation, IgG4-related disease, or arterial and venous thrombosis. The main reason for referral was confirmation or establishment of a diagnosis, and the MDT members were primarily from medical specialties gathered especially for the MDT. Outcomes of the included studies were grouped into process indicators and outcome indicators. Process indicators included changes in diagnostic confirmation as well as therapeutic strategy and management. All studies reporting process indicators demonstrated significant changes before and after the MDT.

CONCLUSION

MDTs within chronic diseases appeared highly heterogeneous with respect to structure, reasons for referral, and choice of outcomes. While process indicators, such as change in diagnosis, and treatment management/plan seem improved, such have not been demonstrated through outcome indicators.

Improving the transparency of meta-analyses with interactive web applications

Increased transparency in study design and analysis is one proposed solution to the perceived reproducibility crisis facing science. Systematic review and meta-analysis-through which individual studies on a specific association are ascertained, assessed for quality and quantitatively combined-is a critical process for building consensus in medical research. However, the conventional publication model creates static evidence summaries that force the quality assessment criteria and analytical choices of a small number of authors onto all stakeholders, some of whom will have different views on the quality assessment and key features of the analysis. This leads to discordant inferences from meta-analysis results and delayed arrival at consensus. We propose a shift to interactive meta-analysis, through which stakeholders can take control of the evidence synthesis using their own quality criteria and preferred analytic approach-including the option to incorporate prior information on the association in question-to reveal how their summary estimate differs from that reported by the original analysts. We demonstrate this concept using a web-based meta-analysis of the association between genetic variation in a key tamoxifen-metabolising enzyme and breast cancer recurrence in tamoxifen-treated women. We argue that interactive meta-analyses would speed consensus-building to the degree that they reveal invariance of inferences to different study selection and analysis criteria. On the other hand, when inferences are found to differ substantially as a function of these choices, the disparities highlight where future research resources should be invested to resolve lingering sources of disagreement.

Hypoxia-inducible factor-1α expression and breast cancer recurrence in a Danish population-based case control study

Background

Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that facilitates the adaptation of cancer cells to hypoxic conditions and may be prognostic of breast cancer recurrence. We evaluated the association of HIF-1α expression with breast cancer recurrence, and its association with timing of breast cancer recurrence.

Methods

In this population-based case-control study, we included women diagnosed with stage I–III breast cancer between 1985 and 2001, aged 35–69 years, registered in the Danish Breast Cancer Group. We identified 541 cases of breast cancer recurrence among women with estrogen receptor (ER)-positive disease who were treated with tamoxifen for at least 1 year (ER+ TAM+). We also enrolled 300 breast cancer recurrence cases among women with ER-negative disease, not treated with tamoxifen, who survived at least 1 year (ER−/TAM−). Controls were recurrence-free breast cancer patients at the time of case diagnosis, matched to recurrence cases on ER/TAM status, date of surgery, menopausal status, cancer stage, and county of residence. Expression of HIF-1α was measured by immunohistochemistry on tissue microarrays. We fitted logistic regression models to compute odds ratios (ORs) and 95% confidence intervals (CIs) associating HIF-1α expression with recurrence, and with timing of recurrence.

Results

HIF-1α expression was observed in 23% of cases and 20% of controls in the ER+/TAM+ stratum, and in 47% of cases and 48% of controls in the ER−/TAM− stratum. We observed a near-null association between HIF-1α expression in both ER/TAM groups (ER+/TAM+ OR = 1.21, 95%CI 0.88, 1.67 and ER−/TAM− OR = 0.97, 95%CI 0.68, 1.39). HIF-1α expression was not associated with time to recurrence among women in the ER+/TAM+ stratum, but was associated with early recurrence among women in the ER−/TAM− stratum.

Conclusion

In this study, HIF-1α expression was not associated with breast cancer recurrence overall but may be associated with early recurrence among women diagnosed with ER− breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01480-1.

No significant influence of OCT1 genotypes on the pharmacokinetics of morphine in adult surgical patients

We investigated the impact of genetic variants in OCT1 (SLC22A1) on morphine, morphine‐3‐glucuronide (M3G) and morphine‐6‐glucuronide (M6G) pharmacokinetics in adult patients scheduled for major surgery. Blood samples were taken before and 5, 10, 15, 30, 45, 60 and 90 min after a bolus of morphine (0.15 mg/kg). Patients were genotyped for the genetic variants (rs12208357, rs34059508, rs72552763 and rs34130495) in OCT1.

Eighty‐six patients completed the trial. The mean difference (95% confidence interval) for dose adjusted morphine, M3G and M6G AUC was 0.9 (−0.7–2.4), −5.9 (−11.8 to −0.03) and −1.1 (−2.5–0.4) h/L*10⁻⁶, respectively, in patients with two reduced function alleles compared to patients with no reduced function alleles in OCT1. Accordingly, the (AUC_M3G/Dose)/(AUC_{morphine/Dose}) and (AUC_M6G/Dose)/(AUC_{morphine/Dose}) ratio was reduced, −1.8 (−3.2 to −0.4) and −0.4 (−0.7 to −0.03), respectively, when comparing the same groups. OCT1 variants had no influence on the experience of pain, adverse events or the number of PCA doses used. In conclusion, genetic variants in OCT1 had a small and clinically unimportant impact on the exposure of morphine after intravenous administration. Our results do not support pre‐emptive genotyping for OCT1 prior to morphine administration in patients scheduled for major surgery.

Socioeconomic position and prognosis in premenopausal breast cancer: a population-based cohort study in Denmark

BACKGROUND

To investigate how socioeconomic position (SEP) influences the effectiveness of cancer-directed treatment in premenopausal breast cancer patients in terms of breast cancer recurrence and mortality.

METHODS

We conducted a cohort study nested in the ProBeCaRe (Predictors of Breast Cancer Recurrence) cohort (n = 5959). We identified all premenopausal women aged 18-55 years diagnosed with non-metastatic breast cancer and prescribed docetaxel-based chemotherapy in Denmark during 2007-2011. Population-based administrative registries provided data on SEP: marital status (married including registered partnership or single including divorced or widowed), cohabitation (cohabiting or living alone), education (low, intermediate, or high), income (low, medium, or high), and employment status (employed, unemployed, or health-related absenteeism). For each SEP measure, we computed incidence rates, cumulative incidence proportions (CIPs), and used Poisson regression to compute incidence rate ratios (IRRs) and 95% confidence intervals (CIs) of recurrence and death. We stratified on estrogen receptor (ER) status/tamoxifen to evaluate interaction.

RESULTS

Our study cohort included 2616 women; 286 (CIP 13%) experienced recurrence and 223 (CIP 11%) died during follow-up (median 6.6 and 7.2 years, respectively). Single women had both increased 5-year risks of recurrence (IRR 1.45, 95% CI 1.11-1.89) and mortality (IRR 1.83, 95% CI 1.32-2.52). Furthermore, we observed increased 5-year mortality in women with low education (IRR 1.49, 95% CI 0.95-2.33), low income (IRR 1.37, 95% CI 0.83-2.28), unemployment (IRR 1.61, 95% CI 0.83-3.13), or health-related work absenteeism (IRR 1.80, 95% CI 1.14-2.82), but smaller or no increased risk of recurrence. These findings were especially evident among women with ER+ tumors prescribed tamoxifen. Overall analyses (follow-up max. 10 years) provided similar results.

CONCLUSIONS

Low SEP in premenopausal women with non-metastatic breast cancer was associated with increased mortality, but not always recurrence. This suggests underdetection of recurrences in certain groups. Poor prognosis in women with low SEP, especially single women, may partly be explained by tamoxifen adherence.

Use of sildenafil and other phosphodiesterase type 5 inhibitors among pregnant women in Scandinavia

INTRODUCTION

For phosphodiesterase type 5 (PDE5) inhibitors, such as sildenafil, the only approved indication in women is for pulmonary arterial hypertension. These drugs are increasingly being proposed and tested for treatment of female infertility and complications in pregnancy. However, the extent of use of PDE5 inhibitors in the general pregnant population over the last decades is unknown. Therefore, we conducted a descriptive cohort study using data from the population health registers in the Scandinavian countries.

MATERIAL AND METHODS

By linking the Medical Birth Registers and the Prescribed Drug Registers in Denmark (1997-2017), Norway (2004-2017), and Sweden (2006-2016), women with filled prescriptions of PDE5 inhibitors in outpatient settings in the 90 days before the date of last menstrual period and/or during pregnancies were identified. With additional linkage to the National Patient Registers, information on maternal, pregnancy, and infant characteristics, co-morbidities, and co-medication was collected and described.

RESULTS

Among over 3 million singleton pregnancies, only 77 were pregnancies in women who had at least one filled prescription of a PDE5 inhibitor within the 90 days before the start of pregnancy to delivery. Prescription fills most often occurred before the last menstrual period and in the first trimester, with very few occurring later in pregnancy. Sildenafil was the most used PDE5 inhibitor. Among pregnant women using PDE5 inhibitors, 44% were 35 years of age or older, eight had a cardiovascular diagnosis, and three specifically had a diagnosis of pulmonary arterial hypertension. Among the infants born to mothers using PDE5 inhibitors, nine were born preterm, six were small-for-gestational age, five had an Apgar score at 5 minutes below 8, 18 were admitted to the Neonatal Intensive Care Unit, and eight had respiratory and cardiovascular conditions.

CONCLUSIONS

Few women used PDE5 inhibitors in outpatient settings before or during pregnancy in the Scandinavian countries in the last decades. Only a small proportion had a diagnosis for pulmonary arterial hypertension, suggesting off-label use in the remaining users. Use was predominantly in mothers over age 35 years. The safety of fetal exposure to sildenafil and other PDE5 inhibitors in pregnancy has not been established. As maternal age continues to increase and additional uses of PDE5 inhibitors are investigated, the safety of these drugs in pregnancy should be thoroughly evaluated.

Use of hypnotic drugs among children, adolescents, and young adults in Scandinavia

BACKGROUND

Hypnotic use in children and adolescents is controversial.

OBJECTIVE

To describe the use of hypnotic drugs (melatonin, z-drugs, and sedating antihistamines) among 5- to 24-year-old Scandinavians during 2012 to 2018.

METHODS

Aggregate-level data were obtained from public data sources in Sweden, Norway, and Denmark. We calculated annual prevalence (users/1000 inhabitants) stratified by age group, sex, and country. Quantity of use (Defined Daily Dose (DDD)/user/day) was estimated for Norway and Denmark.

RESULTS

Melatonin was the most commonly used hypnotic, and its use increased markedly from 2012 to 2018, particularly among females and 15- to 24-year-old individuals. Sweden had the highest increase in use (6.5 to 25/1000) compared with Norway (10-20/1000) and Denmark (5.7-12/1000). The annual prevalence of sedating antihistamine use was also highest in Sweden, reaching 13/1000 in 2018 in comparison to 7.5/1000 in Norway and 2.5/1000 in Denmark. Z-drug use decreased in all countries toward 2018, dropping to 3.5/1000 in Sweden, 4.4/1000 in Norway, and 1.7/1000 in Denmark. The quantity of hypnotic use in Norway and Denmark was 0.8-1.0 DDD/user/day for melatonin in 2018, as compared to 0.1-0.3 for z-drugs and antihistamines.

CONCLUSION

The use of melatonin and sedating antihistamines increased among young Scandinavians during 2012-2018, and the increase was twice as high in Sweden compared with Norway and Denmark. In addition, Sweden had the highest use of sedating antihistamines. The Scandinavian variation of hypnotic use could reflect differences in frequency of sleep problems between populations or variation of healthcare access or clinical practice between countries.

Assessing Techniques for Quantifying the Impact of Bias Due to an Unmeasured Confounder: An Applied Example

Purpose

To compare the magnitude of bias due to unmeasured confounding estimated from various techniques in an applied example.

Patients and Methods

We examined the association between dibutyl phthalate (DBP) and incident estrogen receptor (ER)-positive breast cancer in a Danish nationwide cohort (N=1,122,042). Cox regression analyses were adjusted for age and active drug compounds contributing to DBP exposure. We estimated the hazard ratios (HRs) that would have been observed had one of the DBP sources been unmeasured and calculated the strength of confounding by comparing to the fully adjusted HR. We performed a quantitative bias analysis (QBA) of the “unmeasured” confounder, using external information to specify the bias parameters. Upper bounds on the bias were estimated and E-values were calculated.

Results

The adjusted HR for incident ER-positive breast cancer among women with high-level (≥10,000 cumulative milligrams) versus no DBP exposure was 2.12 (95% confidence interval 1.12 to 4.05). Removing each DBP source in isolation resulted in negligible change in the HR. The bias estimates from the QBA ranged from 1.00 to 1.01. The estimated maximum impact of unmeasured confounding ranged from 1.01 to 1.51. E-values ranged from 3.46 to 3.68.

Conclusion

The impact of bias due to simulated unmeasured confounding was negligible, in part, because the unmeasured variable was not independent of controlled variables. When a suspected confounder cannot be measured in the study data, our exercise suggests that QBA is the most informative method for assessing the impact. E-values may best be reserved for situations where uncontrolled confounding emanates from an unknown confounder.

Oral and intravenous pharmacokinetics of metformin with and without oral codeine intake in healthy subjects: A cross-over study

The aim of the study was to investigate if there is a clinically relevant drug interaction between metformin and codeine. Volunteers were randomized to receive on four separate occasions: (A) orally administered metformin (1 g), (B) intravenously administered metformin (0.5 g), (C) five doses of tablet codeine 25 mg; the last dose was administered together with oral metformin (1 g), and (D) five doses of tablet codeine 25 mg; the last dose was administered together with metformin (0.5 g) intravenously. Blood samples were drawn for 24 h after administration of metformin, and for 6 h after administration of codeine and analyzed using liquid chromatography and tandem mass spectrometry. Healthy volunteers genotyped as CYP2D6 normal metabolizers (*1/*1) without known reduced function variants in the OCT1 gene (rs12208357, rs34130495, rs34059508, and rs72552763) were invited. The median absorption fraction of metformin was 0.31 and was not influenced by codeine intake. The median time to maximum concentration (Tmax) after oral intake of metformin was 2 h without, and 3 h with codeine (p = 0.06). The geometric mean ratios of the areas under the plasma concentration time‐curve (AUCs) for morphine and its metabolites M3G and M6G for oral intake of metformin‐to‐no metformin were 1.21, 1.31, and 1.27, respectively, and for i.v. metformin‐to‐no metformin 1.28, 1.34, and 1.30, respectively. Concomitant oral and i.v. metformin increased the plasma levels of morphine, M3G and M6G. These small pharmacokinetic changes may well contribute to an increased risk of early discontinuation of metformin. Hence, a clinically relevant drug‐drug interaction between metformin and codeine seems plausible.

Abstract 757: 17β-hydroxysteroid dehydrogenases 1 and 2: potential markers for breast cancer recurrence and tamoxifen resistance among premenopausal women diagnosed with breast cancer in Denmark

Background: Breast cancer is the most commonly diagnosed malignancy among women worldwide. Despite high survival rates, 20%-40% of women will experience a recurrence, with risks extending beyond 20 years after diagnosis. Premenopausal women diagnosed with estrogen receptor (ER) positive disease are prescribed 5-10 years of tamoxifen therapy to prevent a recurrence. 17β-hydroxysteroid dehydrogenase 1 and 2 expression (HSD17B1 and HSD17B2, respectively) regulate the relative concentrations of estrogen metabolites and may modify tamoxifen effectiveness. We evaluated the prognostic and predictive value of these biomarkers.

Methods: Premenopausal women diagnosed during 2002-2011 with a first primary stage I-III breast cancer were identified in the Danish Breast Cancer Group database, and categorized based on ER status and receipt of tamoxifen (4600 ER+/TAM+ and 1359 ER−/TAM−). HSD17B1 and HSD17B2 were assayed by immunohistochemistry and scored using automated image analysis [Visiopharm (Hoersholm, Denmark)]. The biomarkers were assessed within ER/TAM strata, to differentiate the enzymes predictive of treatment response from enzymes prognostic for breast cancer recurrence. We used Cox proportional hazards regression and probabilistic bias analysis to account for mismeasurement of biomarker expression and baseline selection bias from tumor sample availability to calculate the hazard ratios (HRs) and 95% simulation intervals (SIs) associating each biomarker with recurrence.

Results: 24% of ER+/TAM+ and 13% of ER−/TAM− breast cancers had any HSD17B1 expression. In the bias-adjusted analyses, women diagnosed with tumors positive for HSD17B1 expression had an increased rate of recurrence: HR=1.40 (95% SI: 1.02, 2.92) in the ER+/TAM+ stratum, and HR=1.32 (95% SI: 0.82, 2.74) in the ER−/TAM− stratum. A 10-unit increase in HSD17B2 expression corresponded with a decreased recurrence rate among women in the ER+/TAM+ (HR=0.85, 95% SI: 0.69, 1.05) stratum, but not among women in the ER−/TAM− stratum (HR=1.07, 95% SI: 0.82, 1.42).

Conclusions: We observed that HSD17B1 expression was associated with a higher rate of recurrence among premenopausal women, and that HSD17B2 expression was associated with a lower rate of recurrence among premenopausal tamoxifen-treated women diagnosed with ER+ disease. HSD17B1 may be an important prognostic marker of breast cancer recurrence among premenopausal breast cancer patients and HSD17B2 may be predictive of response among tamoxifen-treated premenopausal women diagnosed with ER+ breast cancer.

Citation Format: Lindsay Jane Collin, Anders Kjærsgaard, Thomas P. Ahern, Michael Goodman, Lauren E. McCullough, Lance A. Waller, Kristina B. Christensen, Per Damkier, Stephen J. Hamilton-Dutoit, Kristina Lauridsen, Peer M. Chistiansen, Bent Ejlertsen, Henrik Toft Sørensen, Deirdre Cronin-Fenton, Timothy L. Lash. 17β-hydroxysteroid dehydrogenases 1 and 2: potential markers for breast cancer recurrence and tamoxifen resistance among premenopausal women diagnosed with breast cancer in Denmark [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 757.

A Bayesian reanalysis of the effects of hydroxychloroquine and azithromycin on viral carriage in patients with COVID-19

Gautret and colleagues reported the results of a non-randomised case series which examined the effects of hydroxychloroquine and azithromycin on viral load in the upper respiratory tract of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients. The authors reported that hydroxychloroquine (HCQ) had significant virus reducing effects, and that dual treatment of both HCQ and azithromycin further enhanced virus reduction. In light of criticisms regarding how patients were excluded from analyses, we reanalysed the original data to interrogate the main claims of the paper. We applied Bayesian statistics to assess the robustness of the original paper’s claims by testing four variants of the data: 1) The original data; 2) Data including patients who deteriorated; 3) Data including patients who deteriorated with exclusion of untested patients in the comparison group; 4) Data that includes patients who deteriorated with the assumption that untested patients were negative. To ask if HCQ monotherapy was effective, we performed an A/B test for a model which assumes a positive effect, compared to a model of no effect. We found that the statistical evidence was highly sensitive to these data variants. Statistical evidence for the positive effect model ranged from strong for the original data (BF₊₀ ~11), to moderate when including patients who deteriorated (BF₊₀ ~4.35), to anecdotal when excluding untested patients (BF₊₀ ~2), and to anecdotal negative evidence if untested patients were assumed positive (BF₊₀ ~0.6). The fact that the patient inclusions and exclusions are not well justified nor adequately reported raises substantial uncertainty about the interpretation of the evidence obtained from the original paper.

[Phenotype- or genotype test for dihydropyrimidin dehydrogenase deficiency before treatment with a fluoropyrimidine]

Some patients may have partial or complete deficiency of dihydropyrimidin dehydrogenase (DPD) and be more likely to experience severe toxicity with 5-fluorouracil. Since the spring of 2020, the Danish Medicines Agency has recommended genotype or phenotype testing before treatment with a fluoropyrimidine, but the most appropriate test strategy is debated. In this review, we present polymorphisms in the genes coding for DPD and summarise the evidence for DPD-enzyme deficiency testing and pharmacokinetic guided dosing.