Drug-laboratory Test Interactions Research Articles

Drug interference with biochemical laboratory tests.

Clinical laboratory practice represents an essential part of clinical decision-making, as it influences 60-70% of medical decisions at all levels of health care. Results of biochemical laboratory tests (BLTs) have a key role in establishment of adequate diagnosis as well as in evaluation of treatment progress and outcome. The prevalence of drug-laboratory test interactions (DLTIs) is up to 43% of patients who had laboratory results influenced by drugs. Unrecognized DLTIs may lead to misinterpreted BLTs results, incorrect or delayed diagnosis, extra costs for unnecessary additional tests or inadequate therapy, as all may cause false clinical decisions. The significance of timely and adequate recognition of DLTIs is to prevent common clinical consequences such as incorrectly interpreted test results, delayed or non-treated condition due to erroneous diagnosis or unnecessary extra tests or therapy. Medical professionals should be educated that it is essential to obtain patient data about medications especially for the drugs used in the last 10 days before biological material collection. Our mini-review aims to provide a comprehensive overview of the current state in this important domain of medical biochemistry with detailed analysis of the effect of drugs on BLTs and to give detailed information to medical specialists.

Awareness of drug laboratory test interactions is important for prevention of unnecessary additional diagnostics: An example

BackgroundElevated levels of Chromogranin A (CgA) may be indicative of a neuroendocrine tumour (NET), but increased levels are also observed after intake of proton pump inhibitors (PPIs). The incidence of diagnostic confusion because of this drug-laboratory test interaction (DLTI) was examined. MethodsMedical records of 238 patients with elevated CgA concentrations were obtained from three hospitals. The following data were extracted: PPI prescription at the time of CgA measurement, medical decision making based on elevated CgA concentrations, final diagnosis, comorbidity and other prescribed drugs. ResultsFrom 238 patients with elevated CgA concentrations, 132 used PPIs. Of these patients, 57 patients did not have a NET. In 9 of these 57 patients (16%), diagnostic work up revealed no medical cause of an elevated CgA concentration. Somatostatin receptor imaging was ordered in 4 out of 9 cases, with no abnormalities observed. In 6 out of 9 cases, CgA measurement was repeated after PPI discontinuation resulting in normalisation of CgA concentrations. ConclusionIn this retrospective patient record study we observed that part of the elevated CgA concentrations in patients could be caused by the usage of PPIs causing unnecessary diagnostic work-up for the exclusion of a NET. These observations illustrate the need for better DLTI awareness.

Real-time monitoring of drug laboratory test interactions: a proof of concept.

For the correct interpretation of test results, it is important to be aware of drug-laboratory test interactions (DLTIs). If DLTIs are not taken into account by clinicians, erroneous interpretation of test results may lead to a delayed or incorrect diagnosis, unnecessary diagnostic testing or therapy with possible harm for patients. A DLTI alert accompanying a laboratory test result could be a solution. The aim of this study was to test a multicentre proof of concept of an electronic clinical decision support system (CDSS) for real-time monitoring of DLTIs. CDSS was implemented in three Dutch hospitals. So-called 'clinical rules' were programmed to alert medical specialists for possible DLTIs based on laboratory test results outside the reference range in combination with prescribed drugs. A selection of interactions from the DLTI database of the Dutch society of clinical chemistry and laboratory medicine were integrated in 43 clinical rules, including 24 tests and 25 drugs. During the period of one month all generated DTLI alerts were registered in the laboratory information system. Approximately 65 DLTI alerts per day were detected in each hospital. Most DLTI alerts were generated in patients from the internal medicine and intensive care departments. The most frequently reported DLTI alerts were potassium-proton pump inhibitors (16%), potassium-beta blockers (11%) and creatine kinase-statins (11%). This study shows that it is possible to alert for potential DLTIs in real-time with a CDSS. The CDSS was successfully implemented in three hospitals. Further research must reveal its usefulness in clinical practice.

Clinical usefulness of drug-laboratory test interaction alerts: a multicentre survey.

Knowledge of possible drug-laboratory test interactions (DLTIs) is important for the interpretation of laboratory test results. Failure to recognize these interactions may lead to misinterpretation, a delayed or erroneous diagnosis, or unnecessary extra diagnostic tests or therapy, which may harm patients. The aim of this multicentre survey was to evaluate the clinical value of DLTI alerts. A survey was designed with six predefined clinical cases selected from the clinical laboratory practice with a potential DLTI. Physicians from several departments, including internal medicine, cardiology, intensive care, surgery and geriatrics in six participating hospitals were recruited to fill in the survey. The survey addressed their knowledge of DLTIs, motivation to receive an alert and opinion on the potential influence on medical decision making. A total of 210 physicians completed the survey. Of these respondents 93% had a positive attitude towards receiving DLTI alerts; however, the reported value differed per case and per respondent's background. In each clinical case, medical decision making was influenced as a consequence of the reported DLTI message (ranging from 3 to 45% of respondents per case). In this multicentre survey, most physicians stated DLTI messages to be useful in laboratory test interpretation. Medical decision making was influenced by reporting DLTI alerts in each case. Alerts should be adjusted according to the needs and preferences of the receiving physicians.

Effects of calcium dobesilate (CaD) interference on serum creatinine measurements: a national External Quality Assessment (EQA)-based educational survey of drug-laboratory test interactions

Drug-laboratory test interactions (DLTIs) are one of the major sources of laboratory errors. Calcium dobesilate (CaD) interference on serum creatinine testing is a widespread problem that has long been ignored in China. A national EQA-based survey was launched to investigate the current status of CaD interference on creatinine routine methods used in China and enhance the education of CaD interference in clinical laboratories. A descriptive survey was developed to characterize the status quo of Chinese laboratory professionals' cognition to CaD interference. Four of survey samples which were spiked with/without interference additive were shipped to 175 participant laboratories. The target reference values from a reference measurement procedure were compared against the results from participating laboratories to evaluate the CaD interference on serum creatinine measurements using enzymatic method or Jaffé method. The lack of knowledge of DLTIs and the barriers to collect information from pharmacological and laboratory data systems had become the main problems on implementing DLTIs education in China. A significant negative influence of CaD on enzymatic method was observed regardless of measurement platforms. Jaffé method was generally free from interaction with CaD but showed poor precision and accuracy at low creatinine concentrations. More efforts should be made to enhance the education of DLTIs in clinical laboratories in China.

Real-time monitoring of drug-laboratory test interactions with an automated decision support application

Background-aim: The lack of knowledge of the presence of Drug-Laboratory Test Interactions (DLTIs) can cause misinterpretation of laboratory test results and delayed or erroneous diagnosis with extra healthcare costs and even harm to patients. There are over 50.000 physiological and/or analytical drug-test interactions described. In this pilot study, an automated decision support application was used to detect drug laboratory test interactions in real-time. Methods: In this multicentre study, 34 clinical rules about DLTI were programmed and validated in an automated decision support application (Gaston, Medecs B.V.). The DLTIs were described in a validated database from the Dutch Society for Clinical Chemistry. The application is able to generate a DLTI-based advisory text based on predefined aberrant laboratory test results and medication data from individual patients and present this alert text to the laboratory specialist in the laboratory information system. The software application was successfully connected and installed in one hospital laboratory in 2018 with two other hospitals to follow in 2019. Generated real-time DLTI alerts were collected and monitored during 4 weeks. Results: A mean of 45 DLTI alerts were generated per day. Twenty-one out of 34 clinical rules were generated at least once in this period. The most frequently reported interactions were magnesium - proton pump inhibitors (14%), creatine kinase – statins (13%) and potassium - ACE-inhibitors (13%). Most DLTI alerts were from the internal medicine department (43%), cardiology department (22%) and the emergency department (10%). Conclusions: In this study, an automated decision support application was implemented to facilitate signalling the presence of drug laboratory test interactions. A mean of 45 DLTI alerts per day were generated in this study. The clinical relevance of the alerts for laboratory specialists and physicians will be examined.

A structured database with drug-laboratory test interactions as a facilitating tool for the consulting role of laboratory specialists

A structured database with drug-laboratory test interactions as a facilitating tool for the consulting role of laboratory specialists

Diagnostic error as a result of drug-laboratory test interactions.

Background Knowledge of possible drug-laboratory test interactions (DLTIs) is important for the interpretation of laboratory test results. Test results may be affected by physiological or analytical drug effects. Failure to recognize these interactions may lead to misinterpretation of test results, a delayed or erroneous diagnosis or unnecessary extra tests or therapy, which may harm patients. Content Thousands of interactions have been reported in the literature, but are often fragmentarily described and some papers even reported contradictory findings. How can healthcare professionals become aware of all these possible interactions in their individual patients? DLTI decision support applications could be a good solution. In a literature search, only four relevant studies have been found on DLTI decision support applications in clinical practice. These studies show a potential benefit of automated DLTI messages to physicians for the interpretation of laboratory test results. All physicians reported that part of the DLTI messages were useful. In one study, 74% of physicians even sometimes refrained from further additional examination. Summary and outlook Unrecognized DLTIs potentially cause diagnostic errors in a large number of patients. Therefore, efforts to avoid these errors, for example with a DLTI decision support application, could tremendously improve patient outcome.

Impact of interactions between drugs and laboratory test results on diagnostic test interpretation - a systematic review.

Intake of drugs may influence the interpretation of laboratory test results. Knowledge and correct interpretation of possible drug-laboratory test interactions (DLTIs) is important for physicians, pharmacists and laboratory specialists. Laboratory results may be affected by analytical or physiological effects of medication. Failure to take into account the possible unintended influence of drug use on a laboratory test result may lead to incorrect diagnosis, incorrect treatment and unnecessary follow-up. The aim of this review is to give an overview of the literature investigating the clinical impact and use of DLTI decision support systems on laboratory test interpretation. Particular interactions were reported in a large number of articles, but they were fragmentarily described and some papers even reported contradictory findings. To provide an overview of information that clinicians and laboratory staff need to interpret test results, DLTI databases have been made by several groups. In a literature search, only four relevant studies have been found on DLTI decision support applications for laboratory test interpretation in clinical practice. These studies show a potential benefit of automated DLTI messages to physicians for the correct interpretation of laboratory test results. Physicians reported 30-100% usefulness of DLTI messages. In one study 74% of physicians sometimes even refrained from further additional examination. The benefit of decision support increases when a refined set of clinical rules is determined in cooperation with health care professionals. The prevalence of DLTIs is high in a broad range of combinations of laboratory tests and drugs and these frequently remain unrecognized.

Effect of drug‐test interactions on length of hospital stay

To evaluate the impact of drug-laboratory test interactions on the length of stay of hospitalised patients. Observational study of 404 discharges from the Internal Medicine Services of a tertiary hospital. Databases with information on general data, medication and tests performed were linked with the potential interactions described in the literature. This revealed the potential interactions between drugs and laboratory tests (PIDL) in each patient. Several linear regression models, adjusted for confounders, were performed to test the effect of both the number of PIDL and their influence on tests results (false positive/negative) on the length of stay. A total of 19 741 PIDL were detected; 5954 could give rise to potential false positive (PFP) results and 8442 to potential false negative (PFN) ones. Each PFP was related to an increase of 0.051 days in stay duration (CI95% 0.001-0.102) and each PFN to 0.045 days (CI95% 0.008-0.081). Globally, 303 and 380 days of hospitalisation could be attributed to false positives and false negatives, which could account for 9.8% of the total stay of these patients. These results show that the interactions between drugs and laboratory tests produce a statistically and clinically significant increase in the duration of hospital stay.

Unified algorithm for real-time detection of drug interaction and drug allergy

This algorithm aims at unifying and generalizing the algorithm for detecting all types of documented drug interactions such as drug–drug interactions, drug–disease interactions, drug–patient interactions (drug allergy) from patient profile information and drug–laboratory test interactions in real-time prescribing system. Ideally, the system should conform to the following criteria: (1) data independence; (2) software interconnectability; (3) knowledge expandability; (4) flexibility; and (5) computation resource efficiency. We propose a robust Structured Query Language (SQL) algorithm to detect drug interactions and drug allergy according to such criteria. We believe that this is the first public domain algorithm in SQL that could be easily implemented into most open-system prescribing software which support SQL language. The algorithm comprises two major stages: ‘expand’ and ‘extract’. The former expands all information in the prescription with their synonyms, groups, or components. The latter extracts the documented interactions by inner-joining knowledge-base with two independant copies of the expanded prescription list simultaneously. Simulation study for speed performance indicates that this algorithm is well behaved, for the speed of compuation does not grow faster than the growth in prescription size.

Drug-laboratory test interactions section deleted from Drug Interactions

Drug-laboratory test interactions section deleted from Drug Interactions

Computer support of pharmaceutical services for ambulatory patients

A prototype computerized pharmaceutical services support system (CPSSS) is described. CPSSS maintains records on approximately 40,000 patients; 1,300 outpatient prescriptions are dispensed per day. Using Univac hardware and software developed inhouse, CPSSS provides an online drug therapy profile. The prescription label, including auxiliary information, storage and stability guidelines as well as the traditional information, is automatically generated. Prior to medication dispensing, all information is verified by a pharmacist after the computer searches the patient medication profile for 5,400 potential drug-drug, 1,500 drug-disease state, over 100 drug-allergy and 200 drug-laboratory test interactions as well as identifying duplicate pharmacological therapy. Retrospectively, the patient population is described as to sex, age and number of diagnoses. The number of prescriptions per physician also is reported. Twenty drugs represent one-half of the total prescriptions, with 32% of patients taking diuretics and 30% taking tranquilizers. All new prescriptions were prospectively reviewed. Approximately 2% had potential interactions or pharmacological duplication of therapy problems. Approximately 30% of all new prescriptions duplicated exactly an active prescription on file. When a pharmacist initiated physician contact as a result of CPSSS and profile review, physicians changed therapy approximately 73% of the time when informed of duplicate therapy, 27% of the time when informed of potential drug-disease state interactions and 32% of the time when informed of potential drug-drug interactions.

Psychotropic drug therapy knowledge of health care practitioners

The psychotropic drug therapy knowledge of eight types of health care practitioners was studied. An examination, dealing with case studies of schizophrenia, depression and mania, was developed. The categories of practitioners were: (1) clinical pharmacists in psychiatric practice, (2) psychiatrists, (3) physicians (nonpsychiatrists), (4) hospital pharmacists in mental health institutions, (5) hospital pharmacists in nonmental health institutions, (6) community pharmacists, (7) nurses in mental health institutions, and (8) nurses in nonmental health institutions. The specific areas of drug knowledge tested were: diagnosis; drug selection; side effects; adverse reactions; monitoring parameters; influence of other disease states; drug-drug interactions; drug-laboratory test interactions; and clinical drug judgment. Clinical pharmacists in psychiatric practice and psychiatrists had the highest scores, and the scores of these two groups were significantly higher than those of the other groups. Nurses practicing in nonmental health institutions had the lowest scores. The results suggested that clinical pharmacists trained in psychotropic drug therapy may be competent to manage this therapy of patients in mental health institutions. Patients receiving this therapy in nonpsychiatric facilities and in ambulatory environments are being served by physicians, nurses and pharmacists whose knowledge of psychotropic drug therapy may be inadequate.