Undesirable effect - Definition

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An undesirable effect, or side effect, is a harmful, unsought reaction caused by a medicinal, surgical, psychotherapeutic, or mechanical treatment, despite respecting the prescription's instructions. An undesirable effect may result in an allergy, discomfort, complications or even the death of the patient. To mitigate an undesirable effect, a health professional must modify the dose, stop any drug interactions, or interrupt the treatment in progress. From that point on, every patient has the possibility to state the potential undesirable effect on specialized websites, such as on the U.S. Food and Drug Administration website.