OBJECTIVES: This analysis describes the extent and trend of reporting medication errors (ME) in the FDA Adverse Event Reporting System (FAERS). METHODS: Adverse medication events submitted to FAERS through June 2015 were analyzed. ME were defined by MedDRA PT: Drug prescribing, dispensing, administration, and titration errors; device use, dietary supplement prescribing, and vaccination errors; labelled drug-drug, drug-disease, and drug-food interaction medication errors; intercepted drug prescribing, dispensing, and administration errors; intercepted medication error; medication error; medication monitoring error; and transcription medication error. Medication classes were classified by the pharmacological subgroup classification of the Anatomical Therapeutic Chemical (ATC Level 3). Multi-item Gamma Poisson Shrinker disproportionality analysis was applied to estimate signals of ME, which are defined as 2.0≥EB05. RESULTS: Totally 105,373 ME reports were submitted with variable reporting trend: average annual decrease in reporting of 18% (min=3%, max=42%) between 2004 and 2010, and annual increase of 25% (min=2%, max=66%) between 2010 and 2015 Q1-Q2. Signals of reporting ME were prominent in: topical anti-infectives, e.g. silver sulfadiazine (EB05=10); adrenergics, e.g. epinephrine (EB05=6.2); throat preparations, e.g. chlorhexidine (EB05=5.7); cardiac stimulants, e.g. dopamine (EB05=5.0); general anesthetics, e.g. ketamine (EB05=5.0); adsorbents, e.g. charcoal (EB05=4.7); belladonna derivatives, e.g. atropine (EB05=4.4); psychostimulants, e.g. methylamphetamine (EB05=4.2); potassium preparations (EB05=4.0); uterotonics, e.g. misoprostol (EB05=3.7); posterior pituitary hormones, e.g. oxytocin (EB05=3.4); topical decongestants, e.g. phenylephrine (EB05=3.3); topical hemorrhoid agents (EB05=3.3); insulin and analogues (EB05=3.1); systemic corticosteroids; prednisolone (EB05=3.1); topical anti-infectives, e.g. neomycin (EB05=3.0); mydriatics, e.g. tropicamide (EB05=3.0); inhaled bronchodilators, e.g. albuterol (EB05=2.9); multivitamins (EB05=2.7); cardiac vasodilators, e.g. isosorbide (EB05=2.6); idonated contrast media (EB05=2.6); expectorants and antitussives (EB05=2.5); central antiadrenergics, e.g. methyldopa (EB05=2.5); and cardiac glycosides, e.g. digoxin (EB05=2.5). CONCLUSIONS: For some pharmacological classes, ME is a potential risk, and drug utilization studies are suggested to better evaluate the extent of ME in selected medications, e.g. agents for metabolic and cardiovascular disorders.