welltolerated

Well tolerated is a descriptor used in medicine and pharmacology to indicate that a drug, treatment, or procedure produces few or manageable adverse effects in a given population and dose, allowing continuation of therapy. It is commonly found in clinical trial reports, regulatory submissions, and product labeling to convey the overall tolerability profile of an intervention.

Tolerability is assessed through measures such as the frequency, severity, and duration of adverse events; the rate of treatment discontinuation due to adverse effects; dose-limiting toxicities; and patient-reported outcomes related to quality of life. The determination of “well tolerated” is context dependent, influenced by the population studied (age, comorbidities, concomitant medicines), the dosage, duration of exposure, and the comparators used in trials.

Limitations of the term include its subjective nature and variability across studies. A treatment described as well tolerated in a controlled trial may be less tolerable in routine practice, where patient populations are more diverse and monitoring may be less intensive. Also, labeling may summarize tolerability while not detailing all adverse events, or may understate rare or long-term effects. As part of the risk-benefit assessment, tolerability is considered alongside efficacy and safety to determine the overall value of an intervention for a given patient population.

See also: tolerability, safety profile, adverse drug reaction, risk-benefit analysis.