|MedDRA Hierarchy||Medical Dictionary for Regulatory Activities|
|The structure of MedDRA is very logical. There are five levels to the MedDRA hierarchy, arranged from very specific to very general. At the most specific level, called “Lowest Level Terms” (LLTs), there are more than 70,000 terms which parallel how information is communicated. These LLTs reflect how an observation might be reported in practice. This level directly supports assigning MedDRA terms within a user database.
Each member of the next level, “Preferred Terms” (PTs), is a distinct descriptor (single medical concept) for a symptom, sign, disease diagnosis, therapeutic indication, investigation, surgical or medical procedure, and medical social or family history characteristic. Each LLT is linked to only one PT. Each PT has at least one LLT (itself) as well as synonyms and lexical variants (e.g., abbreviations, different word order).
Related PTs are grouped together into “High Level Terms” (HLTs) based upon anatomy, pathology, physiology, etiology or function. HLTs, related to each other by anatomy, pathology, physiology, etiology or function, are in turn linked to “High Level Group Terms” (HLGTs).
Finally, HLGTs are grouped into “System Organ Classes” (SOCs) which are groupings by etiology (e.g. Infections and infestations), manifestation site (e.g. Gastrointestinal disorders) or purpose (e.g. Surgical and medical procedures). In addition, there is a SOC to contain issues pertaining to products and one to contain social circumstances.
|Side Effect||Concept type|
|Show||5-alpha reductase inhibition therapy||LT|
|Show||5-alpha reductase inhibition therapy||PT|
|Show||5-hydroxyindolacetic acid decreased||LT|
The Toxin and Toxin Target Database (T3DB)
The Toxin and Toxin Target Database (T3DB), or, soon to be referred as, the Toxic Exposome Database, is a unique bioinformatics resource that combines detailed toxin data with comprehensive toxin target information. The database currently houses 3,673 toxins described by 41,733 synonyms, including pollutants, pesticides, drugs, and food toxins, which are linked to 2,087 corresponding toxin target records. Altogether there are 42,471 toxin, toxin target associations. Each toxin record (ToxCard) contains over 90 data fields and holds information such as chemical properties and descriptors, toxicity values, molecular and cellular interactions, and medical information. This information has been extracted from over 18,143 sources, which include other databases, government documents, books, and scientific literature.
The focus of the T3DB is on providing mechanisms of toxicity and target proteins for each toxin. This dual nature of the T3DB, in which toxin and toxin target records are interactively linked in both directions, makes it unique from existing databases. It is also fully searchable and supports extensive text, sequence, chemical structure, and relational query searches. It is both modelled after and closely linked to the Human Metabolome Database (HMDB) and DrugBank. Potential applications of T3DB include toxin metabolism prediction, toxin/drug interaction prediction, and general toxin hazard awareness by the public, making it applicable to various fields. Overall, the variety and accessibility of the T3DB make it a valuable resource for both the casual user and the advanced researcher.
Search TOXNET Databases
|MOST VISITED BY TOXNET USERS||HSDB
Hazardous Substances Data Bank. Peer-reviewed toxicology data for over 5,000 hazardous chemicals
4 million references to literature on biochemical, pharmacological, physiological, and toxicological effects of drugs and other chemicals
Comparative Toxicogenomics Database. Access to scientific data describing relationships between chemicals, genes and human diseases
|OCCUPATIONAL EXPOSURE TO CHEMICALS||Haz-Map
Links jobs and hazardous tasks with occupational diseases and their symptoms
Integrated Risk Information System. Hazard identification and dose-response assessment for over 500 chemicals
|ARCHIVED, NO LONGER UPDATED||CPDB
Carcinogenic Potency Database. Standardized analyses of the results of 6,540 chronic, long-term animal cancer tests
FDA's Adverse Event Reporting System (FAERS)
The FDA Adverse Event Reporting System (FAERS) is a database that contains information on adverse event and medication error reports submitted to FDA. The database is designed to support the FDA's post-marketing safety surveillance program for drug and therapeutic biologic products. The informatic structure of the FAERS database adheres to the international safety reporting guidance issued by the International Conference on Harmonisation (ICH E2B). Adverse events and medication errors are coded to terms in the Medical Dictionary for Regulatory Activities (MedDRA) terminology.How Does FDA Use the Information in FAERS?
FAERS is a useful tool for FDA for activities such as looking for new safety concerns that might be related to a marketed product, evaluating a manufacturer's compliance to reporting regulations and responding to outside requests for information. The reports in FAERS are evaluated by clinical reviewers in the Center for Drug Evaluation and Research (CDER) and the Center for Biologics Evaluation and Research (CBER) to monitor the safety of products after they are approved by FDA. If a potential safety concern is identified in FAERS, further evaluation is performed. Further evaluation might include conducting studies using other large databases, such as those available in the Sentinel System. Based on an evaluation of the potential safety concern, FDA may take regulatory action(s) to improve product safety and protect the public health, such as updating a product’s labeling information, restricting the use of the drug, communicating new safety information to the public, or, in rare cases, removing a product from the market.Who Reports to FAERS?
Reporting of adverse events and medication errors by healthcare professionals and consumers is voluntary in the United States. FDA receives some adverse event and medication error reports directly from healthcare professionals (such as physicians, pharmacists, nurses and others) and consumers (such as patients, family members, lawyers and others). Healthcare professionals and consumers may also report adverse events and/or medication errors to the products’ manufacturers. If a manufacturer receives an adverse event report, it is required to send the report to FDA as specified by regulations. The reports received directly and the reports from manufacturers are entered into FAERS.