Final answer:
Dosage Substitution involves adjusting medication amounts based on patient-specific factors including body mass and organ function, to maintain therapeutic levels and minimize toxicity.
Step-by-step explanation:
The concept of Dosage Substitution refers to altering the standard dose of medication, which is crucial for achieving therapeutic drug levels without significant toxicity. When determining the appropriate dosage, various factors are taken into account. For children, dosage is often based on the patient's body mass, but a standard dose is used for adults and children over 12 years, regardless of their body mass. Experts suggest that adult dosages should also consider body mass due to the great variability.
Additionally, how a drug is metabolized and eliminated is critical, especially in patients with liver or kidney problems, as they may experience increased drug levels leading to potential toxicity. It is essential for the dosage to be consistent with recommendations for diagnostic, occupational, and therapeutic exposures.