What are the main responses to medications that affect the elderly and children?

Medications can have varied effects on different populations, particularly the elderly and children, due to physiological differences between age groups. The correct answer encompasses the full spectrum of pharmacokinetic processes: Absorption, Distribution, Metabolism, and Elimination.

Firstly, absorption can be influenced by factors like gastric pH, gastrointestinal motility, and presence of food, which differ in both the elderly and children, affecting how quickly and efficiently a medication is taken up into the bloodstream.

Next, distribution refers to how a drug is dispersed throughout the body. In elderly patients, changes in body composition (like increased fat and decreased lean body mass) and altered protein levels can affect the distribution of certain medications. In children, a greater total body water percentage can also influence how drugs are distributed in their systems.

Metabolism, primarily occurring in the liver, is often slower in the elderly due to decreased liver size and blood flow, while children's metabolic rates can vary based on their age, which affects how drugs are processed.

Lastly, elimination, usually performed by the kidneys, can also be impaired in the elderly due to decreased renal function, and in children, the maturation of renal function affects drug clearance rates.

Understanding how all these factors interplay is crucial in predicting the overall pharmac