Drug Interactions Overview

DrugBank's drug-drug interactions feature provides a list of interactions between the ingredients in specified drug products. The drug products can be identified by name, ingredient ID, product concept ID, or by product code.

There are 3 different types of drug interactions:

  1. Category - Category
  2. Drug - Category
  3. Drug - Drug

Category - Category

In order to create the category-category (cat-cat) drug interactions, we assign drugs to specific categories based on various criteria including but not limited to drug class, associated metabolic enzymes, transporters, physiological properties, and adverse effects. For example, a drug like fluoxetine is included in several categories like 'CYP2D6 inhibitor', 'Selective Serotonin Reuptake Inhibitor' and 'QTc prolonging agent', among others. This information is found in the prescribing information for fluoxetine. Broad category-category interactions have been created, generating interactions for each individual drug based on the categories in which the drug has been placed.

An example of a well-known cat-cat interaction is between 'Anti-inflammatory agents' and 'Anticoagulants' due to the increased risk of bleeding when drugs from these categories are given together. When this cat-cat drug interaction is created, it ensures that every drug in each category is flagged for the interaction.

It is important to note that in some cases, this categorical system may generate drug interactions that are not specifically mentioned in prescribing information for a particular drug, but have a risk of occurring based on physiological effects, chemical properties, route of elimination, or other factors. These theoretical drug interactions have been added to DrugBank to ensure broad coverage of potential drug interactions. Because of this, cat-cat interactions may increase the number of interactions that arise while searching for drug interactions.

Drug - Category

A drug-category interaction is an interaction that occurs between a single drug ingredient and an entire category of drugs. For example, prescribing information for a drug ingredient may include a warning for interactions with CYP3A enzyme inhibitors. For example, acetaminophen can have interactions with anticoagulant drugs.

Drug - Drug

A drug-drug interaction occurs when an interaction between two specific drug ingredients has been identified. For example, it is well-known that clarithromycin and atorvastatin interact with each other (clarithromycin impairs the metabolism of atorvastatin). This interaction is considered a drug-drug interaction because it is a specific interaction between drug ingredients.

When you access the interaction end point, there are different parameters available for the interaction including severity, action, evidence level, management, and references. These are further explored in Parameters & Terminologies