Pharmacokinetics renal function assessment

The optimal dosage regimen for patients with renal insufficiency requires an individualized assessment (Table 77-2). The optimal regimen depends on an accurate characterization of the relationship between the drug s pharmacokinetic parameters and renal function and on an accurate assessment of the patient s residual renal function. 

Elderly Pharmacokinetic profile in elderly patients is not established. Because elderly individuals frequently have a reduced glomerular filtration rate, pay particular attention to assessing renal function before and during ganciclovir therapy. 

A population PK evaluation of patients from the safety and efficacy trials can be used to assess the impact of renal function on the disposition of a drug. Special care must be taken that patients with severe renal impairment are adequately represented in the population. The population PK approach assess the impact of various covariates on the disposition of a drug. Non linear mixed effects modeling may be used to model the relationship between various covariates and pharmacokinetic parameters. CLcr as a measure of renal function may be one of the covariates. This type of approach has it advantageous as it involves assessment of the effect of renal impairment on the PK in the target population. 

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