An adverse drug reaction (ADR) is defined as "a considerably detrimental or unpleasant reaction arising from an intervention related to the use of a therapeutic agent; adverse effects typically anticipate hazards from future administration and warrant prevention, specific treatment, dosage regimen modification, or product withdrawal." An adverse event happens when a patient suffers injury while taking a drug, regardless of whether the drug is suspected of being the cause. ADRs generate a significant proportion of hospital admissions, and hospitalised patients regularly have ADRs that complicate and lengthen their stay. Many of these ADRs can be avoided by exercising greater caution. An ADR usually necessitates the drug's discontinuation or dosage reduction.