Pharmacokinetics dosage regimens

Within the medical community it has been acknowledged that elderly patients often respond to drug therapy differently from their younger counterparts. Aside from alteration of various pharmacokinetic and pharmacodynamic processes, elderly patients tend to suffer from a number of chronic conditions and, thus, have more complex dosage regimens. Additionally, a variety of physical limitations prevalent among the elderly may hinder their ability to self-administer medication. 

During product development, many of the initial non-clinical studies were undertaken in GAA knockout mice (i.e. mice devoid of a functional GAA gene), which serves as an animal model for Pompe s disease. The mice proved useful in assessing the pharmacodynamic effect of Myozyme on glycogen depletion and helped establish appropriate dosage regimens. The mice were also used to evaluate pharmacokinetics and biodistribution of GAA following its administration at clinically relevant doses. 

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. 

Step 4 Calculate individualized treatment regimen Determine treatment goals calculate dosage regimen based on pharmacokinetic characteristics of Ihe drug and the patients renal function... 

Toutain, P.L., Pharmacokinetic/pharmacodynamic integration in dmg development and dosage-regimen optimization for veterinary medicine, AAPS PharmSci., 4, 2002. 

Pharmacokinetics and Drug Dosage Regimen Design—A Possible Application Requiring Construction and Manipulation of a Complex Model and Data Base with an Expert System... 

The Role of Pharmacokinetic Properties in Determining a Dosage Regimen... 

Ziprasidone s pharmacokinetics permit rapid and predictable dose adjustment, with metabolites that are considered to be clinically inactive ( 134). The results of PET pharmacokinetic and pharmacodynamic studies indicate that a twice daily dosage regimen is appropriate. 

Pharmacokinetic principles, in addition to clinical factors such as the state of the patient, are utilized in determining dosage regimens. Factors that relate to the safety and efficacy of the drug, such as activity-toxicity relationships (therapeutic window and side effects), and pharmaceutical factors, such as dosage form and route of administration, must be considered.16... 

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