Excretion Profile Variability

Excretion profile variability reflects interindividual differences in drug and metabolite elimination pathways. Renal excretion variability from glomerular filtration rate differences explains urinary recovery differences. Hepatic extraction variability from metabolising enzyme polymorphisms alters biliary excretion. Age-related physiological changes substantially alter excretion patterns.

Population pharmacokinetic analysis identifies covariates explaining excretion variability. Genetic testing predicting metaboliser phenotypes enables personalised dose optimisation. Renal and hepatic function assessment informs dose adjustments. Drug-drug interactions competing for elimination pathways cause accumulation. Emerging point-of-care testing enables bedside excretion prediction.