Any substance which when absorbed into a living organism may modify one or more of its functions.
Comment: The term is generally accepted for a substance taken for a therapeutic purpose, but is also commonly used for substances of abuse. Just as any substance can be a toxicant, so any substance can be a drug. The term carries with it the implication of use for medical purposes, but also the potential for abuse to produce an effect desired by the abuser, but which is ultimately harmful.

The term "drug" was found in the following pages:

2nd International Conference on Ionization Principles in Organic and Inorganic Mass Spectrometry | EVISA's Agenda of Events
Journals database: Drugs
Instrument database: Elemental Scientific Inc. (ESI) - SC-FIA Autosampler
Scientific publications citing EVISA | EVISA's News
Journals database: European Journal of Drug Metabolism and Pharmacokinetics
Journals database: Drug Testing and Analysis
Company database: Polymer Laboratories
RAFA 2019: 9th International Symposium on Recent Advances in Food Analysis | EVISA's Agenda of Events
US FDA Announces Gadolinium-Based MRI Contrast Agent Warning | EVISA's News
New study finds relationship between organic mercury exposure from Thimerosal-containing vaccines and neurodevelopmental disorders | EVISA's News
Experts detail how rice absorbs arsenic from the soil | EVISA's News
New Study Examines Why Mercury is More Dangerous in Oceans | EVISA's News
Journals database: Drug Metabolism and Disposition
Instrument database: Thermo Scientific - TSQ Quantiva™ Triple Quadrupole Mass Spectrometer
Journals database: Naunyn-Schmiedeberg's Archives of Pharmacology
Too many dental amalgam fillings may increase blood mercury levels | EVISA's News
Arsenic speciation in rice: a question of the rice plant species | EVISA's News
Instrument database: Jasco Inc. - CD-2095 Circular Dichroism Detector
Link database: FDA: Product Safety Information: 3-Nitro (Roxarsone) and Chicken
Company database: Aurora Biomed