Drug safety
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Aminoglycoside nephrotoxicity has been reported in patients with sepsis, and several risk factors have been described. Once-daily dosing and shorter treatment have reduced nephrotoxicity risk, and simplified aminoglycoside monitoring. This review focuses on nephrotoxicity associated with aminoglycosides in the subset of patients with septic shock or severe sepsis. ⋯ Given the mean cost of aminoglycoside nephrotoxicity, these programmes may be cost-effective if its prevalence is above 10 %. However, none of these high-intensity TDM programmes have demonstrated a reduction of aminoglycoside-associated nephrotoxicity in patients with septic shock. Therefore, the questions remain as to, first, whether a TDM programme is relevant and, second, what intensity of TDM is achievable in the ICU, i.e. how it can be practically applied in the ICU setting where urgent care and high workload are substantial obstacles to a sophisticated, optimized aminoglycoside administration.
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Modafinil (Provigil) was marketed in the UK in 1998 to promote wakefulness in the treatment of narcolepsy. In April 2004, the licence was extended to include chronic pathological conditions; 2 years later, the prescription of modafinil was restricted to patients with shift work sleep disorder, narcolepsy and obstructive sleep apnoea/hypopnoea syndrome. Following a recent review of the safety data, the licence has been further restricted to only treat patients with narcolepsy. The review highlighted the degree of off-label usage of modafinil, including patients with multiple sclerosis. ⋯ This study provides important additional safety data on the use of modafinil in patients in 'real-world' use, including those for whom the prescribing indication is outside the terms of licence, as per recent changes to the licensed indications for treatment. In addition to safety data, our study provides useful utilization data. Results from this study indicate that a significant number of women of child-bearing potential had not been commenced on appropriate contraceptive programmes prior to starting modafinil. There were three pregnancies that occurred whilst taking contraception, highlighting the necessity of ensuring effective contraceptive cover for women during and after stopping treatment with modafinil. Analysis of the data showed that the majority of events reported as ADRs or reasons for stopping and ranked events during the first month of treatment had been previously documented with the use of modafinil. Stratification of events according to dose revealed a number of events that occurred at the higher dose only, including serious events such as psychosis. The targeted events for which causality assessments were undertaken confirmed the potential of modafinil to induce certain types of events in individual patients, including cardiac and psychiatric events.
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There has been increased interest in using multiple observational databases to understand the safety profile of medical products during the postmarketing period. However, it is challenging to perform analyses across these heterogeneous data sources. The Observational Medical Outcome Partnership (OMOP) provides a Common Data Model (CDM) for organizing and standardizing databases. OMOP's work with the CDM has primarily focused on US databases. As a participant in the OMOP Extended Consortium, we implemented the OMOP CDM on the UK Electronic Healthcare Record database-The Health Improvement Network (THIN). ⋯ This research demonstrated that information loss due to incomplete mapping of medical and drug codes as well as data structure in the current CDM THIN limits its use for all possible epidemiological evaluation studies. Current HOIs and DOIs predefined by the OMOP were constructed with minimal loss of information and can be used for active surveillance methodological research. The OMOP CDM THIN can be a valuable tool for multiple aspects of pharmacoepidemiological research when the unique features of UK Electronic Health Records are incorporated in the OMOP library.
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The growing interest in using electronic healthcare record (EHR) databases for drug safety surveillance has spurred development of new methodologies for signal detection. Although several drugs have been withdrawn postmarketing by regulatory authorities after scientific evaluation of harms and benefits, there is no definitive list of confirmed signals (i.e. list of all known adverse reactions and which drugs can cause them). As there is no true gold standard, prospective evaluation of signal detection methods remains a challenge. ⋯ A strategy for the construction of a reference standard to evaluate signal detection methods that use EHR has been proposed. The resulting reference standard is by no means definitive, however, and should be seen as dynamic. As knowledge on drug safety evolves over time and new issues in drug safety arise, this reference standard can be re-evaluated.
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A large proportion of potential drug interactions are known from pre-authorization studies, but adverse drug reactions (ADRs) due to interactions (adverse drug interactions) are often first detected through astute observation in clinical practice. Individual case safety reports (ICSRs) are collected from broad patient populations and allow for the identification of groups of similar reports. Systematic screening for adverse drug interactions in ICSRs will require an understanding of which information on these reports can be suggestive of adverse drug interactions. ⋯ Information on plausible time courses and resolution of the adverse reaction upon withdrawal of the drug suspected to have induced the interaction may be a useful element in identifying suspected adverse drug interactions from ICSRs. Of these, plausible time course is by far the most commonly reported element in the three signals studied here. Our analysis also demonstrated the importance of sharing and analysing information available in free text where relevant clinical details are often available, such as those mentioned above, along with severity and dosage changes.