Use of N-nitrosodimethylamine (NDMA) contaminated valsartan products and risk of cancer: Danish nationwide cohort study

Genotoxicity assessments of N-nitrosoethylisopropylamine (NEIPA) and N-nitrosodiisopropylamine (NDIPA) in the C57BL/6J mouse

N-Nitrosamines, known as drug impurities and suspected carcinogens, have drawn significant public concern. In response to drug regulatory needs, the European Medicines Agency (EMA) has previously proposed a carcinogenic potency categorization approach based on the N-nitrosamine α-hydroxylation hypothesis, i.e., that N-nitrosamine mutagenicity increases with the number of α-hydrogen atoms. However, this structure-activity relationship has not been fully tested in vivo. NEIPA (N-nitrosoethylisopropylamine) and NDIPA (N-nitrosodiisopropylamine) are small N-Nitrosamines with similar structures, differing in that the former compound has an additional α-hydrogen atom. In this study, NEIPA and NEIPA doses, 25-100 mg/kg, were administered orally to C57BL/6 J mice for seven consecutive days, and their mutation and DNA damage effects were compared. Compared with NDIPA, the mutagenicity and DNA damage potencies of NEIPA (which contains one more α-hydrogen) were much greater. These differences may be related to their distinct metabolic pathways and target organs. This case study confirms the role of α-hydroxyl modification in the mutagenicity of nitrosamines, with oxidation at the α-hydrogen being a crucial step in the formation of mutagens from N-Nitrosamines, and can inform mutagenicity risk assessment and the formulation of regulatory standards for N-nitrosamine impurities.

Impact of agricultural activities on the occurrence of N-nitrosamines in an aquatic environment

N-Nitrosamines, nitroso compounds with strong carcinogenic effects on humans, have been frequently detected in natural waters. In agricultural areas, there is typically a lack of drinking water treatment processes and distribution systems. As a result, residents often consume groundwater as drinking water which may contain N-nitrosamines, necessitating the investigation of the occurrence, sources, and carcinogenic risk of N-nitrosamines within the groundwater of agricultural areas. This study identified eight N-nitrosamines in groundwater and river water in the Jianghan Plain, a famous agricultural region in central China. N-Nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMOR), N-nitrosopyrrolidine (NPYR), and N-nitrosodi-n-butylamine (NDBA) were detected in groundwater, with NDMA being the main compound detected (up to 52 ng L-1). Comparable concentrations of these N-nitrosamines were also found in river water. From laboratory experiments, we found a tremendous potential for the formation of N-nitrosamines in groundwater. Principal component analysis and multiple linear regression analysis results showed that the primary sources of N-nitrosamines in groundwater were the uses of nitrogen fertilizers and pesticides carrying specific N-nitrosamines such as NPYR. The average total carcinogenic risk values of detected N-nitrosamines were higher than the acceptable risk level (10-5), suggesting a potential carcinogenic risk of groundwater. Further research is urgently needed to minimize N-nitrosamine levels in the groundwater of agricultural areas, particularly in those where pesticides and fertilizers are heavily used.

Bumetanide as a Model NDSRI Substrate: N-nitrosobumetanide Impurity Formation and its Inhibition in Bumetanide Tablets

Nitrosamine compounds are classified as potential human carcinogens, the origin of these impurities can be broadly classified in two categories, nitrosamine impurity found in drug products that are not associated with the Active Pharmaceutical Ingredient (API), such as N-nitrosodimethylamine (NDMA) or nitrosamine impurities associated with the API, such as nitrosamine drug substance-related impurities (NDSRIs). The mechanistic pathway for the formation of these two classes of impurities can be different and the approach to mitigate the risk should be tailored to address the specific concern. In the last couple of years number of NDSRIs have been reported for different drug products. Though, not the only contributing factor for the formation of NDSIRs, it is widely accepted that the presence of residual a nitrites/nitrates in the components used in the manufacturing of the drug products can be the primary contributor to the formation of NDSRIs. Approaches to mitigate the formation of NDSRIs in drug products include the use of antioxidants or pH modifiers in the formulation. The primary objective of this work was to evaluate the role of different inhibitors (antioxidants) and pH modifiers in tablet formulations prepared in-house using bumetanide (BMT) as a model drug to mitigate the formation of N-nitrosobumetanide (NBMT). A multi-factor study design was created, and several bumetanide formulations were prepared by wet granulation with and without sodium nitrite spike (100 ppm) and different antioxidants (ascorbic acid, ferulic acid or caffeic acid) at three concentrations (0.1%, 0.5% or 1% of the total tablet weight). Formulations with acidic and basic pH were also prepared using 0.1 N hydrochloric acid and 0.1 N sodium bicarbonate, respectively. The formulations were subjected to different storage (temperature and humidity) conditions over 6 months and stability data was collected. The rank order of N-nitrosobumetanide inhibition was highest with alkaline pH formulations, followed by formulations with ascorbic acid, caffeic acid or ferulic acid present. In summary, we hypothesize that maintaining a basic pH or the addition of an antioxidant in the drug product can mitigate the conversion of nitrite to nitrosating agent and thus reduce the formation of bumetanide nitrosamines.

Ranitidine Use and Incident Cancer in a Multinational Cohort

Importance

Ranitidine, the most widely used histamine-2 receptor antagonist (H2RA), was withdrawn because of N-nitrosodimethylamine impurity in 2020. Given the worldwide exposure to this drug, the potential risk of cancer development associated with the intake of known carcinogens is an important epidemiological concern.

Objective

To examine the comparative risk of cancer associated with the use of ranitidine vs other H2RAs.

Design, Setting, and Participants

This new-user active comparator international network cohort study was conducted using 3 health claims and 9 electronic health record databases from the US, the United Kingdom, Germany, Spain, France, South Korea, and Taiwan. Large-scale propensity score (PS) matching was used to minimize confounding of the observed covariates with negative control outcomes. Empirical calibration was performed to account for unobserved confounding. All databases were mapped to a common data model. Database-specific estimates were combined using random-effects meta-analysis. Participants included individuals aged at least 20 years with no history of cancer who used H2RAs for more than 30 days from January 1986 to December 2020, with a 1-year washout period. Data were analyzed from April to September 2021.

Exposure

The main exposure was use of ranitidine vs other H2RAs (famotidine, lafutidine, nizatidine, and roxatidine).

Main Outcomes and Measures

The primary outcome was incidence of any cancer, except nonmelanoma skin cancer. Secondary outcomes included all cancer except thyroid cancer, 16 cancer subtypes, and all-cause mortality.

Results

Among 1 183 999 individuals in 11 databases, 909 168 individuals (mean age, 56.1 years; 507 316 [55.8%] women) were identified as new users of ranitidine, and 274 831 individuals (mean age, 58.0 years; 145 935 [53.1%] women) were identified as new users of other H2RAs. Crude incidence rates of cancer were 14.30 events per 1000 person-years (PYs) in ranitidine users and 15.03 events per 1000 PYs among other H2RA users. After PS matching, cancer risk was similar in ranitidine compared with other H2RA users (incidence, 15.92 events per 1000 PYs vs 15.65 events per 1000 PYs; calibrated meta-analytic hazard ratio, 1.04; 95% CI, 0.97-1.12). No significant associations were found between ranitidine use and any secondary outcomes after calibration.

Conclusions and Relevance

In this cohort study, ranitidine use was not associated with an increased risk of cancer compared with the use of other H2RAs. Further research is needed on the long-term association of ranitidine with cancer development.

A collaborative study of the impact of N-nitrosamines presence and ARB recall on ARB utilization - results from IQVIA™ Disease Analyzer Germany

PURPOSE

Regulators are increasingly concerned with  the impact of recalls on drug adherence. In 2018, N-nitrosamines impurities were detected in valsartan containing medical products. Concerned products were immediately recalled in July 2018 by regulatory agencies internationally. In Germany, recalls were issued for valsartan, losartan and irbesartan from July 2018 to March 2019. This study examined angiotensin II receptor blocker (ARB) utilization trends and switching patterns in Germany before and after July 2018.

METHODS

Patients prescribed ARBs from January 2014 to June 2020 in general practices in Germany were included in a collaborative framework common protocol drug utilization study led by the US Food and Drug Administration. Trends in monthly and quarterly proportions of total ARB prescribing were analysed for individual ARBs using descriptive statistics and interrupted time series analysis. The rate of switching to an alternative ARB was analysed before and after the recalls.

RESULTS

The proportion of valsartan prescriptions immediately decreased from 35.9 to 17.8% following the first recalls in July 2018, mirrored by an increased proportion for candesartan. Increased switching from valsartan to candesartan was observed. No increased switching was observed after losartan recalls, whereas for irbesartan, increased switching was observed 6-12 months after the last recall. Increased switching from ARBs to angiotensin-converting enzyme (ACE) inhibitors or ARB treatment discontinuations were not observed.

CONCLUSION

This study showed that patients were able to continue ARB treatment despite the July 2018-March 2019 recalls, although many patients needed to switch to an alternative ARB. The duration of the impact of ARB recalls appeared to be limited.

Risk assessment of N-nitrosamines in food

EFSA was asked for a scientific opinion on the risks to public health related to the presence of N-nitrosamines (N-NAs) in food. The risk assessment was confined to those 10 carcinogenic N-NAs occurring in food (TCNAs), i.e. NDMA, NMEA, NDEA, NDPA, NDBA, NMA, NSAR, NMOR, NPIP and NPYR. N-NAs are genotoxic and induce liver tumours in rodents. The in vivo data available to derive potency factors are limited, and therefore, equal potency of TCNAs was assumed. The lower confidence limit of the benchmark dose at 10% (BMDL10) was 10 μg/kg body weight (bw) per day, derived from the incidence of rat liver tumours (benign and malignant) induced by NDEA and used in a margin of exposure (MOE) approach. Analytical results on the occurrence of N-NAs were extracted from the EFSA occurrence database (n = 2,817) and the literature (n = 4,003). Occurrence data were available for five food categories across TCNAs. Dietary exposure was assessed for two scenarios, excluding (scenario 1) and including (scenario 2) cooked unprocessed meat and fish. TCNAs exposure ranged from 0 to 208.9 ng/kg bw per day across surveys, age groups and scenarios. 'Meat and meat products' is the main food category contributing to TCNA exposure. MOEs ranged from 3,337 to 48 at the P95 exposure excluding some infant surveys with P95 exposure equal to zero. Two major uncertainties were (i) the high number of left censored data and (ii) the lack of data on important food categories. The CONTAM Panel concluded that the MOE for TCNAs at the P95 exposure is highly likely (98-100% certain) to be less than 10,000 for all age groups, which raises a health concern.

The Impact of N-nitrosamine Impurities on Clinical Drug Development

Over the past few years, an increasing number of commercially available drugs have been reported to contain N-nitrosamine impurities above acceptable intake limits. Consequent interruption or discontinuation of the manufacturing and distribution of several marketed drugs has culminated into shortages of marketed drugs, including the antidiabetic drug metformin and the potentially life-saving drug rifampin for the treatment of tuberculosis. Alarmingly, the clinical development of new investigational products has been complicated as well by the presence of N-nitrosamine impurities in batches of marketed drug. In particular, rifampin is a key clinical index drug employed in drug-drug interaction (DDI) studies, and as a result of nitrosamine impurities regulatory bodies no longer accept the administration of rifampin in DDI studies involving healthy subjects. Drug developers are now forced to look at alternative approaches for commonly employed perpetrators, which will be discussed in this review.

HARmonized Protocol Template to Enhance Reproducibility of hypothesis evaluating real-world evidence studies on treatment effects: A good practices report of a joint ISPE/ISPOR task force

PROBLEM

Ambiguity in communication of key study parameters limits the utility of real-world evidence (RWE) studies in healthcare decision-making. Clear communication about data provenance, design, analysis, and implementation is needed. This would facilitate reproducibility, replication in independent data, and assessment of potential sources of bias.

WHAT WE DID

The International Society for Pharmacoepidemiology (ISPE) and ISPOR-The Professional Society for Health Economics and Outcomes Research (ISPOR) convened a joint task force, including representation from key international stakeholders, to create a harmonized protocol template for RWE studies that evaluate a treatment effect and are intended to inform decision-making. The template builds on existing efforts to improve transparency and incorporates recent insights regarding the level of detail needed to enable RWE study reproducibility. The overarching principle was to reach for sufficient clarity regarding data, design, analysis, and implementation to achieve 3 main goals. One, to help investigators thoroughly consider, then document their choices and rationale for key study parameters that define the causal question (e.g., target estimand), two, to facilitate decision-making by enabling reviewers to readily assess potential for biases related to these choices, and three, to facilitate reproducibility.

STRATEGIES TO DISSEMINATE AND FACILITATE USE

Recognizing that the impact of this harmonized template relies on uptake, we have outlined a plan to introduce and pilot the template with key international stakeholders over the next 2 years.

CONCLUSION

The HARmonized Protocol Template to Enhance Reproducibility (HARPER) helps to create a shared understanding of intended scientific decisions through a common text, tabular and visual structure. The template provides a set of core recommendations for clear and reproducible RWE study protocols and is intended to be used as a backbone throughout the research process from developing a valid study protocol, to registration, through implementation and reporting on those implementation decisions.

N-nitrosodimethylamine-Contaminated Valsartan and Risk of Cancer: A Nationwide Study of 1.4 Million Valsartan Users

Background Since July 2018, numerous lots of valsartan have been found to be contaminated with N-nitrosodimethylamine (NDMA). We aimed to assess the association between exposure to valsartan products contaminated with NDMA and the risk of cancer. Methods and Results This study was based on data from the Système National des Données de Santé, which is a national database that includes all French residents' health-related expenses. The target population was consumers of valsartan between January 1, 2013 and December 31, 2017, aged between 40 and 80 years old. The association of exposure to contaminated valsartan with the occurrence of any malignancy and cancer by location was evaluated by fitting Cox proportional hazards models weighted by the inverse probability of treatment. A total of 1.4 million subjects without any history of cancer were included. A total of 986 126 and 670 388 patients were exposed to NDMA-contaminated and uncontaminated valsartan, respectively. The use of the NDMA-contaminated valsartan did not increase the overall risk of cancer (adjusted hazard ratio [aHR], 0.99 [95% CI, 0.98-1.0]). However, exposed patients had a higher risk of liver cancer (aHR, 1.12 [95% CI, 1.04-1.22]) and melanoma (aHR, 1.10 [95% CI, 1.03-1.18]). We estimated a mean of 3.7 and 5.8 extra cases per year per 100 000 person-years of liver cancer and melanoma, respectively. Conclusions Our study was the largest to date to examine cancer risks associated with exposure to NDMA-contaminated valsartan. Our findings suggest a slight increased risk of liver cancer and melanoma in patients exposed to NDMA in regularly taken medications.

Angiotensin II receptor blockers (ARBs) and manufacturing contamination: A retrospective National Register Study into suspected associated adverse drug reactions

AIMS

The aim of this study was to determine if any suspected adverse drug reactions (ADRs) observed with the use of angiotensin II receptor blockers (ARBs) could be linked to either (a) their unique respective physicochemical and pharmacological profiles and (b) the recently disclosed suspected carcinogenic manufacturing contaminants found in certain sartan drug class batches.

METHODS

The pharmacology profiles of ARBs were data-mined from the Chemical Database of bioactive molecules with drug-like properties, European Molecular Biology Laboratory (ChEMBL). Suspected ADR data (from 01/2016-10/2022, inclusive) and prescribing rates of ARBs over a 5-year prescribing window (from 09/2016 to 08/2021, inclusive) were obtained via analysis of the United Kingdom Medicines and Healthcare products Regulatory Authority (MHRA) Yellow Card drug analysis profile and Open prescribing databases, respectively.

RESULTS

The overall suspected ADRs and fatalities per 100 000 prescriptions identified across the ARBs studied were found to be different between the sartan drug class members (chi-squared test, P < .05). There is a greater relative rate of reports for valsartan across all investigated organ classes of ADRs, than other ARBs, despite valsartan's more limited pharmacological profile and similar physicochemical properties to other sartans. The disparity in ADR reporting rates with valsartan vs other ARBs could be due to the dissimilarity in formulation excipients, patient factors and publicity surrounding batch contaminations, amongst others. Cancer-related ADRs and fatalities per 100 000 prescriptions identified across the ARBs studied are not statistically significant (chi-squared test, P > .05) based on the datasets used over the 5-year period.

CONCLUSION

No connection between ARB pharmacology and their suspected ADRs could be found. No conclusion between sartan batch contaminations and increased suspected cancer-related ADRs was found.

Itraconazole Contaminated with Rilmazafone in Japan: A Retrospective Analysis Using the Japanese Adverse Drug Event Report Database

Background

In early December 2020, the antifungal medication, itraconazole (ITCZ), was mistakenly contaminated with rilmazafone in Japan. Healthcare professionals reported adverse drug reaction reports associated with ITCZ and included central nervous system-depression symptoms such as dizziness, lightheadedness, loss of consciousness, and intense drowsiness.

Objective

We examined ITCZ-associated suspicious cases using the Japanese Adverse Drug Event Report (JADER) database to determine the impact of adverse drug reaction reporting on post-marketing safety measures.

Methods

Adverse drug reaction reports in which the suspicious or concomitant medication was ITCZ or fluconazole (FLCZ) were extracted from the JADER dataset. The number of adverse drug reaction reports associated with central nervous system-depression adverse drug reactions were counted, and chronological changes were compared with ITCZ and FLCZ.

Results

Of the 713,893 adverse drug reaction reports in the JADER database, 5048 cases were associated with ITCZ and 6007 cases with FLCZ. When ITCZ contamination occurred, the number of adverse drug reaction reports associated with ITCZ increased rapidly, while those with FLCZ did not. In addition, the proportion of central nervous system-depression adverse drug reactions increased only in the ITCZ-associated report.

Conclusions

An incident of ITCZ contamination with rilmazafone was detected on the JADER retrospectively. This case highlights the importance of spontaneous adverse drug reaction reporting, even if the causal relationship between the drug and adverse drug reaction is unknown.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-022-00306-6.

Ranitidine Use and Gastric Cancer Among Persons with Helicobacter pylori

BACKGROUND

The Food and Drug Administration requested withdrawal of ranitidine formulations, due to a potentially carcinogenic contaminant, N-nitrosodimethylamine.

AIMS

We evaluate whether ranitidine use is associated with gastric cancer.

METHODS

This is a retrospective multicenter, nationwide cohort study within the Veterans Health Administration, among patients with Helicobacter pylori (HP) prescribed long-term acid suppression with either: (1) ranitidine, (2) other histamine type 2 receptor blocker (H2RB), or (3) proton pump inhibitor (PPI)) between May 1, 1998, and December 31, 2018. Covariates included race, ethnicity, smoking, age, HP treatment, HP eradication. Primary outcome was non-proximal gastric adenocarcinomas, using multivariable Cox proportional hazards analysis.

RESULTS

We identified 279,505 patients with HP prescribed long-term acid suppression (median 53.4 years; 92.9% male). Compared to ranitidine, non-ranitidine H2RB users were more likely to develop cancer (HR 1.83, 95%CI 1.36-2.48); PPI users had no significant difference in future cancer risk (HR 0.92, 95% CI 0.82-1.04), p < 0.001. Demographics associated with future cancer included increasing age (HR 1.18, 95% CI 1.15-1.20, p < 0.001), Hispanic/Latino ethnicity (HR 1.46, 95% CI 1.21-1.75, p < 0.001), Black race (HR 1.89, 95% CI 1.68-2.14) or Asian race (HR 2.03, 95% CI 1.17-3.52), p < 0.001, and gender (female gender HR 0.64, 95% CI 0.48-0.85, p = 0.02). Smoking was associated with future cancer (HR 1.38, 95% CI 1.23-1.54, p < 0.001). Secondary analysis demonstrated decreased cancer risk in those with confirmed HP eradication (HR 0.24, 95% CI 0.14-0.40). No association between ranitidine and increased gastric cancer was found.

CONCLUSION

There is no demonstrable association between ranitidine use and future gastric cancer among individuals with HP on long-term acid suppression.

Cancer Risk of Angiotensin II Receptor Blocker Valsartan: A Population-based Study

ABSTRACT

Nitrosamine contamination of generic valsartan was found in 2018. This study aimed to investigate whether long-term use of valsartan increases cancer risk. Patients prescribed valsartan or amlodipine (control group) from 1 January 1, 2003, to June 30, 2010, were identified using the Clinical Data Analysis and Reporting System of the Hong Kong Hospital Authority, a territory-wide database in Hong Kong. Patients previously diagnosed with cancer, prescribed both medications, taking the medication, or followed up for <1 year were excluded. Cancer incidence, adjusted for age, sex, and Charlson Comorbidity Index, was the primary outcome and was estimated using Poisson regression in R version 3.6.1. Among 5023 valsartan users and 3692 amlodipine users, 887 and 740 were diagnosed with cancers during median follow-up periods of 10.97 and 12.12 years, respectively. The adjusted incidence of cancer in valsartan and amlodipine users was 165.29 (95% confidence interval 154.76-175.53) and 180.12 (167.35-193.67) per 10,000 person-years, respectively. The cancer incidence rate ratio of valsartan relative to amlodipine was 0.94 (0.88-1.01). Adjusted incidence rate ratios of valsartan relative to amlodipine were significant for breast cancer (0.63, 0.46-0.86) only. Our findings do not suggest an increase in incidence of cancer with long-term valsartan use. The duration of follow-up of more than 10 years of the study provides the reassurance that an increase in cancer risk is unlikely. Further studies are needed to elucidate the long-term effect of valsartan use on the risk of specific types of cancer.

High level nitrosamines in rat faeces with colorectal cancer determined by a sensitive GC-MS method

N-nitrosamines (NAs) are common toxic substances that have a strong correlation with many human diseases, such as liver damage and cancer. However, there is a lack of studies on methods involving the detection of NAs in biological samples, possibly owing to the interference of complex biological matrices and the influence of endogenous NAs. In this work, solid-phase extraction with mixed solid phases and adsorption sedimentation were used to successfully establish a gas chromatography-mass spectrometry (GC-MS) method for detecting eight NAs in rat faeces. Chromatographic separation of analytes was performed with Agilent VF-WAXms (30 m × 0.25 mm, 0.25 µm) GC columns. The LLOQs of eight NAs were set to the concentration of 0.5 ng/g and the obtained standard curves were linear, and correlation coefficients (r) were ≥ 0.99 for samples with concentration ranges of 0.5-500 ng/g. The inter and intra-assay precisions were< 15% for all analytes in the quality control samples, and the accuracies ranged from 88.67% to 108.33%. The extraction recoveries were above 78.56% for seven NAs, and a significant matrix effect was not observed. The application of this method revealed that the levels of NAS in the faeces of rats with colorectal cancer were higher than those of normal rats. Additionally, the effect of a high nitrite diet on NAs in faeces was analysed; the results confirmed that a high nitrite diet might contribute to an abnormal increase in NAs. Our work provides an analytical method for further in vivo study of NAs. Furthermore, a pilot study on the relationship between NAs and colorectal cancer was completed.

Ranitidine and Risk of Bladder and Kidney Cancer: A Population-Based Cohort Study

BACKGROUND

In 2019, ranitidine was withdrawn due to high levels of N-nitrosodimethylamine, a probable human carcinogen. The risk of bladder and kidney cancer in ranitidine users, however, remains unclear.

METHODS

In a Danish nationwide cohort study, we included adults (18 years or older) without previous cancer, who between 1996 and 2008 redeemed at least two prescriptions for ranitidine and, as two separate comparison cohorts, patients with at least two prescriptions for other H2-receptor antagonists (H2-blockers), or proton pump inhibitors (PPI). Follow-up for bladder or kidney cancer started at date of the second prescription and continued to date of cancer, death, emigration, or December 31, 2018, whichever occurred first. We used propensity scores for ranitidine use to compute stabilized inverse probability of treatment (sIPT) weights and used Cox regression to compute crude and weighted HRs.

RESULTS

We identified 31,393 initiators of ranitidine, 65,384 initiating other H2-blockers, and 509,849 initiating PPI. Compared with other H2-blockers, the crude HR for bladder cancer was 1.33 [95% confidence interval (CI): 1.15-1.55], but sIPT weighting attenuated this to 1.11 (95% CI: 0.95-1.29). Compared with PPI initiators, the weighted HR was 1.24 (95% CI: 1.04-1.48). For kidney cancer, the weighted HR was 0.89 (95% CI: 0.72-1.10) compared with users of H2-blockers and 0.87 (95% CI: 0.67-1.13) compared with users of PPI.

CONCLUSIONS

Our findings did not suggest a substantial increase in bladder or kidney cancer occurrence in ranitidine users.

IMPACT

These findings are reassuring for previous ranitidine users.

The quality of medical products for cardiovascular diseases: a gap in global cardiac care

Objective

Good quality cardiovascular medicines and devices are crucial in the prevention and management of the ever-growing threats of cardiovascular diseases (CVDs) globally. Yet our current understanding of the extent and impact of substandard and falsified (SF) cardiovascular medical products is poor. Our objective was to review the available literature on SF cardiovascular medicines/devices, with a focus on prevalence studies to discuss their impacts on public health.

Methods

Searches were conducted in Embase, PubMed, Web of Science, Google Scholar, Google and websites with interest in medicines/devices quality up to 31 August 2020. Articles in English and French identified in these searches were screened for eligibility. The Medicine Quality Assessment Reporting Guidelines was used to assess the quality of prevalence surveys, and we report according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

Results

A total of 279 articles were included, which were subcategorised into prevalence surveys (n=28), equivalence studies (n=118), stability studies (n=5), routine quality control analyses (n=15), bioavailability studies (n=2), recalls/seizures/case reports (n=77), general discussions (n=24) and reviews (n=10). A failure frequency (defined as the proportion of samples that failed at least one quality test described in the report) of 525 (15.4%) was observed for the 3414 samples tested for quality in the 27 prevalence surveys with sufficient information for inclusion in our quantitative analysis. Nineteen surveys (70.4%) used convenience outlet sampling. The majority (88.8%, 3032/3414) of samples included in prevalence surveys were collected from low-income and middle-income countries. The most common defects were out-of-specification active ingredient(s) content, impurity/contaminant content and impaired dissolution. We found 26 incidents describing SF cardiovascular devices with 181 related deaths but no prevalence surveys.

Conclusion

The data suggest that SF cardiovascular products are likely to be a serious public health problem that has received limited attention. We do not suggest that 15.4% of cardiovascular medicines are SF, and our findings highlight the need for more research with robust methodology to provide more accurate prevalence estimates in order to inform policy and implement measures to ensure the quality of cardiovascular medicines and devices within the supply chain. Ensuring that CVD medical products are of good quality would help ensure effectiveness and that the benefits of therapy are realised in the prevention and treatment of CVDs.

Estimated Cancer Risks Associated with Nitrosamine Contamination in Commonly Used Medications

Many nitrosamines are potent carcinogens, with more than 30 listed under California's Proposition 65. Recently, nitrosamine contamination of commonly used drugs for treatment of hypertension, heartburn, and type 2 diabetes has prompted numerous Food and Drug Administration (FDA) recalls in the US. These contaminants include the carcinogens NDMA (N-nitrosodimethylamine) and NDEA (N-nitrosodiethylamine) and the animal tumorigen NMBA (N-nitroso-N-methyl-4-aminobutyric acid). NMBA and NDEA are metabolically and/or structurally related to NDMA, an N-nitrosomethyl-n-alkylamine (NMA), and 12 other carcinogenic NMAs. These nitrosamines exhibit common genotoxic and tumorigenic activities, with shared target tumor sites amongst chemicals and within a given laboratory animal species. We use the drug valsartan as a case study to estimate the additional cancer risks associated with NDMA and NDEA contamination, based on nitrosamine levels reported by the US FDA, cancer potencies developed by California's Proposition 65 program and the US Environmental Protection Agency (EPA), and specific exposure scenarios. These estimates suggest that nitrosamine contamination in drugs that are used long-term can increase cancer risks and pose a serious concern to public health.

No association between chronic use of ranitidine, compared with omeprazole or famotidine, and gastrointestinal malignancies

BACKGROUND

In 2019, the United States Food and Drug Administration detected above-regulation levels of the human carcinogen N-nitrosodimethylamine (NDMA) in ranitidine, resulting in a complete removal of the medication from the market. NDMA is known to cause gastrointestinal malignancies in animal models.

AIM

To determine if patients who were receiving ranitidine have a higher risk of developing cancers of the digestive tract compared to patients taking other anti-reflux medications.

METHODS

Using the nationwide database IBM Explorys, patients taking ranitidine were compared to patients on either famotidine or omeprazole. Incidence data of new malignancies of the oesophagus, stomach, liver, pancreas, and colon/rectum were obtained in 1-year intervals for up to 10 years. Two multivariable logistic regression models were used to calculate odds ratios (ORs), one adjusting for common risk factors for each cancer studied, and the other for demographic factors.

RESULTS

Patients on ranitidine who were compared to patients on famotidine had ORs of 0.51(95% CI 0.43-0.60), 0.43(95% CI 0.36-0.51), 0.39(95% CI 0.36-0.41), 0.54(95% CI 0.49-0.62), and 0.46(95% CI 0.43-0.49) of developing oesophageal, gastric, hepatocellular, pancreatic, and colorectal cancers, respectively (P < 0.001). Patients on ranitidine compared to omeprazole had ORs of 0.62(95% CI 0.52-0.72), 0.58(95% CI 0.49-0.68), 0.81 (95% CI 0.76-0.86), 0.68(95% CI 0.60-0.76), and 0.66(95% CI 0.62-0.70) of developing oesophageal, gastric, hepatocellular, pancreatic, and colorectal cancers respectively (P < 0.001).

CONCLUSIONS

Use of ranitidine was not associated with an increased odds of developing gastrointestinal malignancies compared to omeprazole or famotidine use.

Neoplasm Reports in Food and Drug Administration Adverse Event Reporting System Following Angiotensin Receptor Blocker Recalls

BACKGROUND

A worldwide voluntary recall of valsartan in July 2018 due to the potential carcinogen N-nitrosodimethylamine received extensive media and public attention. This was followed by more Food and Drug Administration (FDA) recalls regarding other contaminated ARB (angiotensin receptor blocker) products. Our study investigated the association between the FDA recalls and ARB neoplasm adverse events (AEs) reported to the FDA adverse event reporting system.

METHODS

In this cross-sectional study, data were retrospectively collected from the FDA adverse event reporting system database from January 2015 to December 2019. Reporting odds ratios (RORs) were estimated to detect signals of association between ARBs (valsartan, irbesartan, and losartan) and reported neoplasm AEs using negative (amoxicillin and sertraline) and positive (omeprazole and ranitidine) control exposures. The χ² was used to compare categorical variables.

RESULTS

A total of 2 181 524 AEs, including 10 461 nonmetastatic neoplasm AEs were analyzed. Monthly RORs (95% CI) of valsartan-associated neoplasms versus controls (ROR*: valsartan/negative exposures; ROR†: valsartan/omeprazole; and ROR‡: valsartan/ranitidine) showed the highest signals after the recall date in July 2018 (7.64 [4.78-12.19]*; 4.77 [3.36-6.79]†; 4.13 [2.50-6.84]‡) and August 2018 (7.87 [5.19-11.94]*; 5.65 [4.12-7.75]†; and 7.20 [4.46-11.63]‡). In contrast, the highest cancer signals for the irbesartan and losartan recalls detected in March 2019 (4.80*; 4.06†; and 3.38‡) and April 2019 (3.63*; 3.69†; and 2.52‡) respectively, were lower. One-year postrecall reported neoplasm AEs were ≈2-fold higher for valsartan than irbesartan (OR, 1.77 [95% CI, 1.47-2.13], P<0.0001) and losartan (OR, 2.07 [95% CI, 1.85-2.32], P<0.0001). Although all ARBs had the same nitrosamine contamination, we found 1-year postrecall versus prerecall cancer signals for valsartan were 3-fold higher versus control exposures, while the changes in RORs for irbesartan and losartan were only 20-30% higher.

CONCLUSIONS

Significantly more postrecall neoplasms were reported for valsartan, with higher valsartan-associated cancer signals compared with irbesartan and losartan, although they all contained the same carcinogenic contaminant. Extensive media coverage of the FDA valsartan recall may have alarmed patients and generated these abrupt, biologically infeasible cancer signals.

N-Nitrosodimethylamine-Contaminated Valsartan and the Risk of Cancer

BACKGROUND

N-Nitrosodimethylamine (NDMA), classified as a probable human carcinogen, has been found as a contaminant in the antihypertensive drug valsartan. Potentially carcinogenic effects associated with the consumption of NDMAcontaminated valsartan have not yet been analyzed in large-scale cohort studies. We therefore carried out the study reported here to explore the association between NDMA-contaminated valsartan and the risk of cancer.

METHODS

This cohort study was based on longitudinal routine data obtained from a large German statutory health insurance provider serving approximately 25 million insurees. The cohort comprised patients who had filled a prescription for valsartan in the period 2012-2017. The endpoint was an incident diagnosis of cancer. Hazard ratios (HR) for cancer in general and for certain specific types of cancer were calculated by means of Cox regression models with time-dependent variables and adjustment for potential confounders.

RESULTS

A total of 780 871 persons who had filled a prescription for valsartan between 2012 and 2017 were included in the study. There was no association between exposure to NDMA-contaminated valsartan and the overall risk of cancer. A statistically significant association was found, however, between exposure to NDMA-contaminated valsartan and hepatic cancer (adjusted HR 1.16; 95% confidence interval [1.03; 1.31]).

CONCLUSION

These findings suggest that the consumption of NDMA-contaminated valsartan is associated with a slightly increased risk of hepatic cancer; no association was found with the risk of cancer overall. Close observation of the potential long-term effects of NDMA-contaminated valsartan seems advisable.

Exposure to Ranitidine and Risk of Bladder Cancer: A Nested Case-Control Study

INTRODUCTION

Ranitidine has been shown to contain the carcinogen N-nitrosodimethylamine and increase urinary N-nitrosodimethylamine in humans. We investigated whether ranitidine use is associated with increased bladder cancer risk.

METHODS

A nested case-control study was conducted within the Primary Care Clinical Informatics Unit Research database which contains general practice records from Scotland. Bladder cancer cases, diagnosed between 1999 and 2011, were identified and matched with up to 5 controls (based on age, sex, general practice, and date of registration). Ranitidine, other histamine-2 receptor agonists, and proton pump inhibitors were identified from prescribing records. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression after adjusting for comorbidities and smoking.

RESULTS

There were 3,260 cases and 14,037 controls. There was evidence of an increased risk of bladder cancer in ranitidine users, compared with nonusers (fully adjusted OR = 1.22; 95% CI 1.06-1.40), which was more marked with use for over 3 years of ranitidine (fully adjusted OR = 1.43; 95% CI 1.05-1.94). By contrast, there was little evidence of any association between proton pump inhibitor use and bladder cancer risk based on any use (fully adjusted OR = 0.98; 95% CI 0.88-1.11) or over 3 years of use (fully adjusted OR = 0.98; 95% CI 0.80-1.20).

DISCUSSION

In this large population-based study, the use of ranitidine particularly long-term use was associated with an increased risk of bladder cancer. Further studies are necessary to attempt to replicate this finding in other settings.

Cancer risk from nitrosamine-contaminated valsartan

Overview of: Gomm W, Röthlein C, Bowl K, et al Valsartan contaminated with N-nitrosodimethylamine and cancer risk: a longitudinal cohort study with German health insurance data. Dtsch Arztebl Int 2021; 118:357-62. doi: 10.3238/arztebl.m2021.0129.

A genome-wide portrait of pervasive drug contaminants

Using a validated yeast chemogenomic platform, we characterized the genome-wide effects of several pharmaceutical contaminants, including three N-nitrosamines (NDMA, NDEA and NMBA), two related compounds (DMF and 4NQO) and several of their metabolites. A collection of 4800 non-essential homozygous diploid yeast deletion strains were screened in parallel and the strain abundance was quantified by barcode sequencing. These data were used to rank deletion strains representing genes required for resistance to the compounds to delineate affected cellular pathways and to visualize the global cellular effects of these toxins in an easy-to-use searchable database. Our analysis of the N-nitrosamine screens uncovered genes (via their corresponding homozygous deletion mutants) involved in several evolutionarily conserved pathways, including: arginine biosynthesis, mitochondrial genome integrity, vacuolar protein sorting and DNA damage repair. To investigate why NDMA, NDEA and DMF caused fitness defects in strains lacking genes of the arginine pathway, we tested several N-nitrosamine metabolites (methylamine, ethylamine and formamide), and found they also affected arginine pathway mutants. Notably, each of these metabolites has the potential to produce ammonium ions during their biotransformation. We directly tested the role of ammonium ions in N-nitrosamine toxicity by treatment with ammonium sulfate and we found that ammonium sulfate also caused a growth defect in arginine pathway deletion strains. Formaldehyde, a metabolite produced from NDMA, methylamine and formamide, and which is known to cross-link free amines, perturbed deletion strains involved in chromatin remodeling and DNA repair pathways. Finally, co-administration of N-nitrosamines with ascorbic or ferulic acid did not relieve N-nitrosamine toxicity. In conclusion, we used parallel deletion mutant analysis to characterize the genes and pathways affected by exposure to N-nitrosamines and related compounds, and provide the data in an accessible, queryable database.

Nitrosamine Contamination in Pharmaceuticals: Threat, Impact, and Control

Nitrosamine-contaminated medicinal products have raised safety concerns towards the use of various drugs, not only valsartan and all tetrazole-containing angiotensin II receptor blockers, but also ranitidine, metformin, and other medicines, many of which have been recalled and prone to shortage. At any stages, from drug substance synthesis throughout each product's lifetime, these impurities may evolve if an amine reacts with a nitrosating agent coexisting under appropriate conditions. Consequently, drug regulatory authorities worldwide have established stringent guidelines on nitrosamine contamination for all drug products in the market. This review encompasses various critical elements contributing to successful control measures against current and upcoming nitrosamine issues, ranging from accumulated knowledge of their toxicity concerns and potential root causes, precise risk evaluation, as well as suitable analytical techniques with sufficient sensitivity for impurity determination. With all these tools equipped, the impact of nitrosamine contamination in pharmaceuticals should be mitigated. An evaluation aid to tackle challenges in risk identification, as well as suitable industry-friendly analytical techniques to determine nitrosamines and other mutagenic impurities, are among unmet needs that will significantly simplify the risk assessment process.

Excision of mutagenic replication-blocking lesions suppresses cancer but promotes cytotoxicity and lethality in nitrosamine-exposed mice

N-Nitrosodimethylamine (NDMA) is a DNA-methylating agent that has been discovered to contaminate water, food, and drugs. The alkyladenine DNA glycosylase (AAG) removes methylated bases to initiate the base excision repair (BER) pathway. To understand how gene-environment interactions impact disease susceptibility, we study Aag-knockout (Aag-/-) and Aag-overexpressing mice that harbor increased levels of either replication-blocking lesions (3-methyladenine [3MeA]) or strand breaks (BER intermediates), respectively. Remarkably, the disease outcome switches from cancer to lethality simply by changing AAG levels. To understand the underlying basis for this observation, we integrate a suite of molecular, cellular, and physiological analyses. We find that unrepaired 3MeA is somewhat toxic, but highly mutagenic (promoting cancer), whereas excess strand breaks are poorly mutagenic and highly toxic (suppressing cancer and promoting lethality). We demonstrate that the levels of a single DNA repair protein tip the balance between blocks and breaks and thus dictate the disease consequences of DNA damage.

Tolerability of risk: A commentary on the nitrosamine contamination issue

For decades, regulators have grappled with different approaches to address the issue of control of impurities. Safety-based limits, such as permissible daily exposure (PDE), acceptable intake (AI), threshold of toxicological concern (TTC) and less than lifetime limits (LTL) have all been used. For many years these safety-based limits have been recognized as virtually safe doses (VSDs). Recently, however, many regulatory agencies are seeking to impose limits for N-nitrosamine impurities, which are significantly below the VSD. This commentary will discuss the evolution of safety-based limits for impurities, provide an overview of the valsartan N-nitrosamine contamination issue and review the toxicology of N-nitrosamines. The outcome of a lessons-learned exercise on sartan medications undertaken by the European Medicines Agency (EMA) will also be discussed. The review will also highlight the many analytical challenges inherent with controlling impurities to ppb-based limits. The use of highly sensitive, low ppb limits, methods may lead to future issues of batch rejection, based on false positives. Regulators initially viewed the N-nitrosamine risk as being insufficient to prompt immediate product discontinuation and patients were specifically advised to continue using their affected medication. Patients were also informed that exposure to N-nitrosamines is extremely common via food and drinking water.

What is the significance of nitrosamine contamination in medicines?

Topics for DTB review articles are selected by DTB's editorial board to provide concise overviews of medicines and other treatments to help patients get the best care. Articles include a summary of key points and a brief overview for patients. Articles may also have a series of multiple choice CME questions.

Carcinogenesis: Failure of resolution of inflammation?

Inflammation in the tumor microenvironment is a hallmark of cancer and is recognized as a key characteristic of carcinogens. However, the failure of resolution of inflammation in cancer is only recently being understood. Products of arachidonic acid and related fatty acid metabolism called eicosanoids, including prostaglandins, leukotrienes, lipoxins, and epoxyeicosanoids, critically regulate inflammation, as well as its resolution. The resolution of inflammation is now appreciated to be an active biochemical process regulated by endogenous specialized pro-resolving lipid autacoid mediators which combat infections and stimulate tissue repair/regeneration. Environmental and chemical human carcinogens, including aflatoxins, asbestos, nitrosamines, alcohol, and tobacco, induce tumor-promoting inflammation and can disrupt the resolution of inflammation contributing to a devastating global cancer burden. While mechanisms of carcinogenesis have focused on genotoxic activity to induce mutations, nongenotoxic mechanisms such as inflammation and oxidative stress promote genotoxicity, proliferation, and mutations. Moreover, carcinogens initiate oxidative stress to synergize with inflammation and DNA damage to fuel a vicious feedback loop of cell death, tissue damage, and carcinogenesis. In contrast, stimulation of resolution of inflammation may prevent carcinogenesis by clearance of cellular debris via macrophage phagocytosis and inhibition of an eicosanoid/cytokine storm of pro-inflammatory mediators. Controlling the host inflammatory response and its resolution in carcinogen-induced cancers will be critical to reducing carcinogen-induced morbidity and mortality. Here we review the recent evidence that stimulation of resolution of inflammation, including pro-resolution lipid mediators and soluble epoxide hydrolase inhibitors, may be a new chemopreventive approach to prevent carcinogen-induced cancer that should be evaluated in humans.

Application of capillary electrophoresis-nano-electrospray ionization-mass spectrometry for the determination of N-nitrosodimethylamine in pharmaceuticals

After a presence of highly hepatotoxic and potentially carcinogenic N-nitrosodimethylamine was detected in certain lots of sartan, ranitidine, metformin, and other pharmaceuticals, local regulatory authorities issued recalls of suspected products, and concerns of the pharmacotherapy safety were widely discussed. Since then, testing of a representative sample of each produced lot of these pharmaceuticals is required as a part of quality control processes. Hence, an interface-free CE-nanoESI system coupled with MS detection was employed for the development of a simple and economical method for quantitative detection of this contaminant in the valsartan drug substances and finished formulations used as model matrices. In this arrangement, a fused-silica capillary was used as both a separation column and a nanoESI emitter providing high ionization efficiency and sensitivity. The optimized procedure was found to have sufficient selectivity, linearity, accuracy, and precision. The established LOD and LOQ values were 0.3 and 1.0 ng/mL, respectively. The practical applicability of the method was tested by analyses of commercially available Valsacor^® tablets. The results obtained prove that the developed procedure represents a promising alternative to currently available GC- and LC-based methods. Furthermore, after an adjustment of the separation conditions, the CE-nanoESI/MS system can be conceptually used for the determination of NDMA in other suspected pharmaceuticals.

Risk of Cancer Following the Use of N-Nitrosodimethylamine (NDMA) Contaminated Ranitidine Products: A Nationwide Cohort Study in South Korea

N-nitrosodimethylamine (NDMA), a known carcinogenic agent, was recently detected in some products of ranitidine. Several studies have investigated the detectability of NDMA, in drugs and their risks. However, only a few epidemiological studies have evaluated cancer risk from the use of such individual drugs. This study investigates the risk of cancer in ranitidine users. We conducted an observational population-based cohort study using the Health Insurance Review and Assessment databases, which contain information about the use of medicines in South Korea. The primary study cohort consisted of ranitidine users (n = 88,416). For controls, we enrolled users of famotidine, another H₂-receptor antagonist in which no NDMA has been detected. A 4:1 matched cohort was constructed to compare cancer outcomes of the two groups. Our matched cohort comprised of 40,488 ranitidine users and 10,122 famotidine users. There was no statistical difference in the overall cancer risk between the ranitidine and famotidine groups (7.45% vs. 7.56%, HR 0.99, 95% CI 0.91-1.07, p = 0.716). Additionally, no significant differences were observed in the analysis of 11 single cancer outcomes. We found no evidence that exposure to NDMA through ranitidine increases the risk of cancer.

Use of ACE (Angiotensin-Converting Enzyme) Inhibitors and Risk of Lung Cancer: A Nationwide Nested Case-Control Study

BACKGROUND

Use of angiotensin-converting enzyme inhibitors (ACEIs)was associated with increased risk of lung cancer in a cohort study from the United Kingdom. We aimed to replicate these findings in a Danish population.

METHODS

We conducted a nested case-control study using data from 4 Danish national health and administrative registries. New users of ACEIs or angiotensin II receptor blockers in Denmark from January 1, 2000 were followed until December 31, 2015, incident lung cancer, death, or emigration. Each lung cancer case was matched with up to 20 controls on age, sex, duration of follow-up, and year of cohort entry using risk-set sampling. Conditional logistic regression was used to estimate odds ratios (ORs) for incident, histologically verified lung cancer with high use of ACEIs defined as a cumulative dose above 3650 defined daily doses. We examined different cumulative doses of ACEI (≤1800, 1801-3650, >3650 defined daily doses), examined whether the association varied with lung cancer histology, and repeated the analyses using thiazides as active comparator.

RESULTS

We included 9652 lung cancer cases matched to 190 055 controls. High use of ACEIs was associated with lung cancer (adjusted OR, 1.33 [95% CI, 1.08-1.62]). Lower cumulative doses showed neutral associations (≤1800 defined daily doses OR, 1.01 [95% CI, 0.94-1.09]; 1801-3650 defined daily doses OR, 1.03 [95% CI, 0.90-1.19]). CIs were wide and included the null when stratifying on histology. Using thiazides as active comparator yielded comparable results (OR, 1.34 [95% CI, 0.96-1.88]).

CONCLUSIONS

Use of high cumulative ACEI doses was associated with modestly increased odds of lung cancer although use of lower doses showed neutral associations. The established benefits of ACEIs should be considered when interpreting these findings.

A Review on the Fate of Legacy and Alternative Antimicrobials and Their Metabolites during Wastewater and Sludge Treatment

Antimicrobial compounds are used in a broad range of personal care, consumer and healthcare products and are frequently encountered in modern life. The use of these compounds is being reexamined as their safety, effectiveness and necessity are increasingly being questioned by regulators and consumers alike. Wastewater often contains significant amounts of these chemicals, much of which ends up being released into the environment as existing wastewater and sludge treatment processes are simply not designed to treat many of these contaminants. Furthermore, many biotic and abiotic processes during wastewater treatment can generate significant quantities of potentially toxic and persistent antimicrobial metabolites and byproducts, many of which may be even more concerning than their parent antimicrobials. This review article explores the occurrence and fate of two of the most common legacy antimicrobials, triclosan and triclocarban, their metabolites/byproducts during wastewater and sludge treatment and their potential impacts on the environment. This article also explores the fate and transformation of emerging alternative antimicrobials and addresses some of the growing concerns regarding these compounds. This is becoming increasingly important as consumers and regulators alike shift away from legacy antimicrobials to alternative chemicals which may have similar environmental and human health concerns.

Understanding the molecular-pharmaceutical basis of sartan recalls focusing on valsartan

Angiotensin receptor blockers (ARBs) or the 'sartans' are widely used for the management of hypertension and heart failure. There have been a series of recent incidents where drug formulations containing different ARBs as active pharmaceutical ingredients have been recalled by various pharmaceutical firms. This article addresses valsartan as well as other sartan recalls besides discussing the recent recalls of ranitidine and metformin, giving insights into the molecular-pharmaceutical basis of the recalls. A thorough literature search of PubMed/Medline and Google Scholar databases was performed to identify all relevant articles and information published up to 29th April 2020 using Medical Subject Headings (MeSH terms) and Boolean operators. We also searched for relevant information on the web using web-browsers and reference lists from original research papers and review articles. The main impurity found was N-nitrosodimethylamine (NDMA) which was thought to be formed due to a change in the manufacturing process of valsartan. Besides, other impurities such N-nitrosodiethylamine (NDEA) and N-nitroso-N-methyl-4-aminobutyric acid (NMBA) were found in batches of other sartans, such as losartan and irbesartan. All of these are carcinogens and harmful if consumed at a level beyond a certain acceptable daily limit. Ranitidine, and more recent metformin recalls, have also been linked with valsartan in view of the presence of NDMA, the same impurity. Safety of ARBs is a major concern among healthcare professionals after the recalls of valsartan in the recent years. Periodic quality assessment of the manufacturing process and the drugs is key to ensure safe, effective and high-quality drugs for the global population. Additionally, practising physicians need to be vigilant in reporting adverse events in their patients receiving treatments.

Risk of Cancer in Association with Ranitidine and Nizatidine vs Other H2 Blockers: Analysis of the Japan Medical Data Center Claims Database 2005-2018

INTRODUCTION

In September 2019, ranitidine and nizatidine were suggested to contain N-nitrosodimethylamine, a carcinogenic substance. People have since been concerned about the potential impact of ranitidine/nizatidine use on the risk of cancer.

OBJECTIVE

The objective of this study was to investigate the risk of cancer among people receiving ranitidine or nizatidine compared with other histamine 2 receptor antagonists (H2 blockers) [cimetidine, famotidine, roxatidine, and lafutidine].

METHODS

In the Japan Medical Data Center claims database (comprising people aged < 75 years) from 2005 to 2018, we identified new adult users of H2 blockers and classified them into ranitidine/nizatidine users and other H2 blocker users. We estimated the incidence of cancer diagnosis in each group and conducted a multivariable Cox regression analysis.

RESULTS

We identified 113,745 new users of ranitidine/nizatidine (median age 41.2 years [interquartile range 31.7-51.1]; 49.1% men; median follow-up 2.4 years [1.1-4.5]) and 503,982 new users of other H2 blockers (median age 40.9 years [31.1-51.2]; 51.0% men; median follow-up 2.3 years [0.9-4.2]). The incidence rate of cancer diagnosis was 6.39 (95% confidence interval 6.13-6.66) cases per 1000 person-years (top three sites: breast 14.8%; colorectal 14.6%; and stomach 11.5%) in the ranitidine/nizatidine group and 6.17 (6.05-6.30) cases per 1000 person-years (colorectal 14.7%; breast 13.5%; and stomach 11.2%) in the other H2 blockers group. The adjusted hazard ratio (ranitidine/nizatidine users vs other H2 blocker users) was 1.02 (0.98-1.07). The results were similar by follow-up length, by cancer site, and when ranitidine and nizatidine users were separately compared with the other H2 blockers group. By cumulative dose, the adjusted hazard ratio (95% confidence interval) was 1.03 (0.98-1.08) from 1 to 180 defined daily doses (DDDs), 1.00 (0.73-1.39) from 181 to 365 DDDs, 0.95 (0.61-1.48) from 366 to 730 DDDs, and 0.83 (0.45-1.55) at > 730 DDDs.

CONCLUSIONS

We found no evidence that ranitidine/nizatidine is associated with an increased risk of cancer, although further studies with more accurate measurement of exposure, inclusion of older people, and longer follow-up may be needed.

N-Nitrosodimethylamine Contamination in the Metformin Finished Products

A GC–MS/MS method with EI ionization was developed and validated to detect and quantify N-nitrosodimethylamine (NDMA) and seven other nitrosamines in 105 samples of metformin tablets from 13 different manufactures. Good linearity for each compound was demonstrated over the calibration range of 0.5–9.5 ng/mL. The assay for all substances was accurate and precise. NDMA was not detected in the acquired active pharmaceutical ingredient (API); however, NDMA was detected in 64 (85.3%) and 22 (91.7%) of the finished product and prolonged finished product samples, respectively. European Medicines Agency recommends the maximum allowed limit of 0.032 ppm in the metformin products. Hence, 28 finished products and 7 pronged dosage products were found to exceed the acceptable limit of daily intake of NDMA contamination. The implications of our findings for the testing of pharmaceutical products are discussed.

Renin-angiotensin system and cancer: epidemiology, cell signaling, genetics and epigenetics

Day by day, the health and economical burden of cancer increases globally. Indeed it can be considered that there is ''cancer pandemic''. Blocking the renin-angiotensin system (RAS) by angiotensin-converting enzyme (ACE) inhibitors (ACEI) or angiotensin-receptor blockers (ARB) are widely used measures to treat hypertension and heart failure. It has been recently suggested the activation and blocking of RAS has been associated with various types of cancer in epidemiological and experimental studies. Various studies have shown that RAS blockage is protective in some cancers. However, although fewer, contradictory data also showed that RAS blockage is either not related or adversely related to cancer. Although the reasons for these findings are not exactly known, different types of receptors and effectors in RAS may account for these findings. In the current review, we summarize the different RAS receptors and cancer development with regard to epidemiology, and pathogenesis including cell signaling pathways, apoptosis, genetic and epigenetic factors.

Pharmacists are key in interpreting clinical implications of N-nitrosodimethylamine contamination in medications

NDMA is a semivolatile organic chemical classified as a probable carcinogen by the International Agency for Research on Cancer. NDMA exposure to humans is potentially vast, with reports of it occurring in tobacco products, food, water, interior air of cars, toiletries, and a variety of other household goods. Public attention has recently focused on NDMA contamination because it has been implicated in the recall of several medications, including valsartan, losartan, irbesartan, and, most recently, the removal of ranitidine from the market. Its potential for elevated risk of cancer has sparked concern in the health care community. Pharmacists are uniquely situated to process and use this complex information because of their extensive pharmacokinetic and pharmacodynamic knowledge of medications, direct and regular contact with patients, insights and familiarity with recalls, and ability to discuss alternative medications that may alleviate a patient's concerns. It is important to communicate the context and clinical relevance of NDMA contamination to both patients and fellow health care clinicians. Pharmacists can help balance the potential adverse effects of switching medication and the concern related to NDMA in making an informed health decision.

Predicting associations among drugs, targets and diseases by tensor decomposition for drug repositioning

Background

Development of new drugs is a time-consuming and costly process, and the cost is still increasing in recent years. However, the number of drugs approved by FDA every year per dollar spent on development is declining. Drug repositioning, which aims to find new use of existing drugs, attracts attention of pharmaceutical researchers due to its high efficiency. A variety of computational methods for drug repositioning have been proposed based on machine learning approaches, network-based approaches, matrix decomposition approaches, etc.

Results

We propose a novel computational method for drug repositioning. We construct and decompose three-dimensional tensors, which consist of the associations among drugs, targets and diseases, to derive latent factors reflecting the functional patterns of the three kinds of entities. The proposed method outperforms several baseline methods in recovering missing associations. Most of the top predictions are validated by literature search and computational docking. Latent factors are used to cluster the drugs, targets and diseases into functional groups. Topological Data Analysis (TDA) is applied to investigate the properties of the clusters. We find that the latent factors are able to capture the functional patterns and underlying molecular mechanisms of drugs, targets and diseases. In addition, we focus on repurposing drugs for cancer and discover not only new therapeutic use but also adverse effects of the drugs. In the in-depth study of associations among the clusters of drugs, targets and cancer subtypes, we find there exist strong associations between particular clusters.

Conclusions

The proposed method is able to recover missing associations, discover new predictions and uncover functional clusters of drugs, targets and diseases. The clustering of drugs, targets and diseases, as well as the associations among the clusters, provides a new guiding framework for drug repositioning.

Understanding and Preventing (N-Nitrosodimethylamine) NDMA Contamination of Medications

N-nitrosodimethylamine (NDMA) is a hepatotoxic agent and carcinogen contaminant in commonly used medications such as valsartan, losartan, irbesartan, and ranitidine. NDMA can be produced during manufacture, introduced from contaminated ingredients procured elsewhere, or introduced from contaminated solvents and catalysts. The Food and Drug Administration has established a maximum dose of NDMA that is permissible per tablet and guidance for manufacturers. However, many unanswered questions about NDMA contamination need rigorous investigation.

Rapid and efficient high-performance liquid chromatography analysis of N-nitrosodimethylamine impurity in valsartan drug substance and its products

In July 2018, certain valsartan-containing drugs were voluntary recalled in Japan owing to contamination with N-nitrosodimethylamine (NDMA), a probable human carcinogen. In this study, an HPLC method was developed for the quantitative detection of NDMA simultaneously eluted with valsartan. Good linearity with a correlation coefficient (R²) > 0.999 was achieved over the concentration range of 0.011-7.4 µg/mL. The limits of detection and quantification were 0.0085 μg/mL and 0.0285 μg/mL, respectively. When the recalled valsartan samples were subjected to this method, the observed NDMA contents were in agreement with the reported values, indicating that our method achieved sufficient linearity, accuracy, and precision to detect NDMA in valsartan drug substances and products. Moreover, six samples (valsartan drug substances and tablet formulations), which had a possibility for NDMA contamination, were analyzed; none of the samples contained NDMA at detectable levels. Our method would be useful for the rapid screening and quantification of NDMA impurity in valsartan drug substances and products.

Lesson Learnt from Recall of Valsartan and Other Angiotensin II Receptor Blocker Drugs Containing NDMA and NDEA Impurities

The presence of N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) impurities in angiotensin II receptor blocker (ARB) drugs containing tetrazole ring has triggered worldwide product recalls. The purpose of this article is to identify the potential gap area in current pharmaceutical industry practice that might have led to the NMDA and NDEA impurities escaping the drug manufacturer's and FDA's attention. The impact of process change was not adequately assessed by the manufacturer of contaminated APIs (active pharmaceutical ingredients), and potential for generation of mutagenic or other toxic impurities was not considered. The safety and risk associated with a chemical synthetic process was also not evaluated. This is primarily due to current industry practice which focuses on controlling the impurities above reporting threshold. ICH Q3A and FDA guidance on genotoxic and carcinogenic impurities in drug substances and products need to be integrated so that the ICH Q3A decision tree (attachment 3) begins by checking whether the synthetic process has been evaluated for the potential to generate toxic impurities. The compliance with ICH Q3A limits should be carried out only after the process has been determined to be safe without the risk of generating mutagenic and carcinogenic impurities.