Precision dosing increasingly combines pharmacokinetic models, organ-function estimates, therapeutic drug monitoring, pharmacogenomic information, and exposure–response evidence. Yet the availability of more patient-specific data does not ensure that a safer or more defensible dose decision can be made. This Current Opinion argues that precision dosing should prioritize actionability before data abundance. Actionability is defined here as the extent to which a dosing signal is sufficiently reliable, temporally relevant, mechanistically interpretable, linked to a clinically meaningful target, and operationally usable to justify a dose action for a particular patient. Kidney function illustrates the problem because filtration estimates are indirect, may disagree across biomarkers, and may become rapidly outdated during changing physiology. Therapeutic drug monitoring is similarly dependent on sampling time, assay interpretation, target validity, and turnaround. Pharmacogenomic information can provide durable prior knowledge, but genotype does not always equal current phenotype when drug interactions or other modifiers are present. Exposure–response evidence supplies the therapeutic objective, yet an accurately predicted exposure is useful only if the target itself is adequately supported. The article therefore develops a proposed precision-dosing actionability architecture in which heterogeneous signals are interpreted according to reliability, temporal validity, target linkage, decision leverage, and uncertainty rather than simply accumulated. The approach is intended as an organizing framework, not a validated dosing algorithm. Its application remains bounded by drug-specific evidence, patient heterogeneity, model performance, assay availability, implementation conditions, and the need for prospective validation against both exposure and patient-important outcomes.
