Adverse drug reactions caused by drug-drug interactions reported to Croatian Agency for Medicinal Products and Medical Devices: a retrospective observational study

Aim

To analyze potential and actual drug-drug interactions reported to the Spontaneous Reporting Database of the Croatian Agency for Medicinal Products and Medical Devices (HALMED) and determine their incidence.

Methods

In this retrospective observational study performed from March 2005 to December 2008, we detected potential and actual drug-drug interactions using interaction programs and analyzed them.

Results

HALMED received 1209 reports involving at least two drugs. There were 468 (38.7%) reports on potential drug-drug interactions, 94 of which (7.8% of total reports) were actual drug-drug interactions. Among actual drug-drug interaction reports, the proportion of serious adverse drug reactions (53 out of 94) and the number of drugs (n = 4) was significantly higher (P < 0.001) than among the remaining reports (580 out of 1982; n = 2, respectively). Actual drug-drug interactions most frequently involved nervous system agents (34.0%), and interactions caused by antiplatelet, anticoagulant, and non-steroidal anti-inflammatory drugs were in most cases serious. In only 12 out of 94 reports, actual drug-drug interactions were recognized by the reporter.

Conclusion

The study confirmed that the Spontaneous Reporting Database was a valuable resource for detecting actual drug-drug interactions. Also, it identified drugs leading to serious adverse drug reactions and deaths, thus indicating the areas which should be in the focus of health care education.Adverse drug reactions (ADR) are among the leading causes of mortality and morbidity responsible for causing additional complications (1,2) and longer hospital stays. Magnitude of ADRs and the burden they place on health care system are considerable (3-6) yet preventable public health problems (7) if we take into consideration that an important cause of ADRs are drug-drug interactions (8,9). Although there is a substantial body of literature on ADRs caused by drug-drug interactions, it is difficult to accurately estimate their incidence, mainly because of different study designs, populations, frequency measures, and classification systems (10-15).Many studies including different groups of patients found the percentage of potential drug-drug interactions resulting in ADRs to be from 0%-60% (10,11,16-25). System analysis of ADRs showed that drug-drug interactions represented 3%-5% of all in-hospital medication errors (3). The most endangered groups were elderly and polimedicated patients (22,26-28), and emergency department visits were a frequent result (29). Although the overall incidence of ADRs caused by drug-drug interactions is modest (11-13,15,29,30), they are severe and in most cases lead to hospitalization (31,32).Potential drug-drug interactions are defined on the basis of on retrospective chart reviews and actual drug-drug interactions are defined on the basis of clinical evidence, ie, they are confirmed by laboratory tests or symptoms (33). The frequency of potential interactions is higher than that of actual interactions, resulting in large discrepancies among study findings (24).A valuable resource for detecting drug-drug interactions is a spontaneous reporting database (15,34). It currently uses several methods to detect possible drug-drug interactions (15,29,35,36). However, drug-drug interactions in general are rarely reported and information about the ADRs due to drug-drug interactions is usually lacking.The aim of this study was to estimate the incidence of actual and potential drug-drug interactions in the national Spontaneous Reporting Database of ADRs in Croatia. Additionally, we assessed the clinical significance and seriousness of drug-drug interactions and their probable mechanism of action.     

The catechol-O-methyltransferase (COMT) Val158Met polymorphism moderates the effect of antenatal stress on childhood behavioural problems: longitudinal evidence across multiple ages

Aim The functional polymorphism Val158Met in the catechol‐O‐methyltransferase (COMT) gene was analysed to determine its association with maternal stress and childhood total difficulties. Method Data were collected at birth from a group of infants who were born small for gestational age and a group who were born at an appropriate size for gestational age and had been enrolled in the Auckland Birthweight Collaborative Study. Children were followed up at the ages of 1 year, 3 years 6 months, 7 years, and 11 years. At the age of 11 years, DNA samples were collected from 546 children (270 females, 276 males): 227 children born small for gestational age and 319 children born at an appropriate size for gestational age. The main independent variable was perceived maternal stress at birth and at 7 and 11 years of age, assessed using the total difficulties scale of the Strength and Difficulties Questionnaire. IQ was assessed at the age of 7 years. Results Met/Met homozygotes were at a significantly increased risk of behavioural and emotional problems at the ages of 7 (p=0.002) and 11 years (p=0.003), relative to either heterozygous or homozygous carriers of the Val158Met polymorphism, but only when they were exposed to maternal stress in utero. Met/Met homozygotes had, on average, IQ scores that were four points higher than those of Val/Val homozygotes (p=0.010). Interpretation These findings emphasize the potential long‐term consequences of prenatal stress for genetically susceptible individuals during neurodevelopment in utero. Our findings add to the general understanding of the aetiology and developmental nature of childhood emotional and behavioural problems.     

Autism classified by magnetic resonance imaging: A pilot study of a potential diagnostic tool

ObjectivesIndividual anatomical biomarkers have limited power for the classification of autism. The present study introduces a multivariate classification approach using structural magnetic resonance imaging data from individuals with and without autism.MethodsThe classifier utilizes z‐normalization, parameter weighting, and interindividual comparison on brain segmentation data, for estimation of an individual summed total index (TI). The TI indicates whether the gross morphological pattern of each individual''s brain is in the direction of cases or controls.ResultsMorphometric analysis found significant differences within subcortical gray matter structures and limbic areas. There was no significant difference in total brain volume. A case‐control pilot‐study of TIs in normally intelligent individuals with autism (24) and without (21) yielded a maximal accuracy of 78.9% following cross‐validation. It showed a high accuracy compared with machine learning methods when tested on the same dataset. The TI correlated well with the autism quotient (R = 0.51) across groups.ConclusionThese results are on par with studies on autism using machine learning. The main contributions are its transparency and simplicity. The possibility of including additional neuroimaging data further increases the potential of the classifier as a diagnostic aid for neuropsychiatric disorders, as well as a research tool for neuroscientific investigations.     

Digene HPV Genotyping RH Test RUO: Comparative evaluation with INNO-LiPA HPV Genotyping Extra Test for detection of 18 high-risk and probable high-risk human papillomavirus genotypes

BackgroundStandardized and validated methods for the specific detection and identification of a spectrum of high-risk (hr) HPV genotypes will be necessary if HPV genotyping gains an important role in the clinical management of HPV-related precancerous lesions and cancers.ObjectivesThe first comparative evaluation of novel HPV genotyping Digene HPV Genotyping RH Test RUO (Qiagen, Hilden, Germany) with standard INNO-LiPA HPV Genotyping Extra CE assay (Innogenetics, Gent, Belgium).Study designSeventy hr-HPV positive samples were tested in parallel with both genotyping assays. The results were interpreted taking into account 15 hr-HPV and 3 probable hr-HPV genotypes that can be identified by both assays (assay-common genotypes).ResultsConcordant results (a complete match of assay-common genotypes or negative using both assays) and compatible results (at least one genotype in common) were obtained in 42 (60.0%) and 28 (40.0%) samples, respectively. No discordant results for assay-common genotypes were obtained. Of 42 samples with compatible results, the presence of at least one assay-common genotype was detected in 37 samples, while no HPV was detected in two samples by both assays and only a single low-risk HPV was detected by INNO-LiPA in three samples.ConclusionsA novel Digene test is suitable for the detection of hr-HPV genotypes in clinical samples and it provides comparable results to the well established INNO-LiPA assay. Although INNO-LiPA identified significantly more samples with multiple HPV genotypes than the Digene test, the clinical benefit of such a difference is at present unclear.