tolerability

Tolerability refers to the degree to which a therapy's adverse effects and overall burden are acceptable to a patient, allowing continuation of treatment. It's distinct from safety (risk of harm) and efficacy (therapeutic benefit). Tolerability focuses on patient experience and the balance of benefits and harms that patients are willing to endure. It is commonly assessed in pharmacology, clinical medicine, and regulatory science.

Evaluation methods include patient-reported outcome measures, treatment discontinuation rates, dose modifications, time to discontinuation, and clinician assessments of adverse effects. In clinical trials, tolerability is a key endpoint and influences dose selection and labeling. Acceptability is linked to quality of life and adherence; poor tolerability can lead to nonadherence and suboptimal outcomes.

Factors influencing tolerability include patient age, comorbidities, genetic factors, organ function, concomitant medications, dosing regimens, and routes of administration. Strategies to improve tolerability include gradual dose titration, alternative formulations or schedules, supportive care for side effects, education, shared decision-making, and close monitoring. Regulatory agencies emphasize tolerability data when evaluating new therapies.