Reporting of therapeutic ineffectiveness through adverse drug reaction spontaneous reporting systems has been proposed by some authors. In the WHO Adverse Reactions Terminology (WHO-ART) and Medical Dictionary for Regulatory Activities (MedDRA) terminology, the term therapeutic ineffectiveness includes drug interactions, resistance, tolerance and tachyphylaxis, as well as pharmaceutical defects such as substandard, adulterated, and counterfeit drugs. Under certain circumstances, reporting therapeutic ineffectiveness may contribute to identifying pharmaceutical defects. However, the best approach to avoid their occurrence would be implementing good manufacturing practices and strengthening quality control activities. This would prevent the misuse of spontaneous reporting of adverse drug reactions (e.g. when reporting of therapeutic ineffectiveness is 'suggested' by interested parties, especially when a generic product has been substituted for a branded original product).