Final answer:
Medicine dosages often change with age due to immunosenescence, altered drug metabolism, muscle mass changes, etc., necessitating a personalized medicine approach to maximize benefits and minimize risks.
Step-by-step explanation:
The dosage of medicine often changes as a person gets older due to several physiological changes that occur with aging. One such change is the natural decline in the efficacy of the immune system, also known as immunosenescence, which typically begins around age 50 and makes older individuals more susceptible to diseases. The process of aging also affects the body's ability to metabolize and eliminate drugs, with reduced liver and kidney function potentially leading to higher drug levels in the body and an increased risk of toxicity. Therefore, careful consideration of dosage and route of administration is crucial to balance maximizing drug efficacy and minimizing the risk of side effects.
In addition to immune system changes and altered drug metabolism, other factors such as muscle mass decrease, slower reflexes, and the development of chronic conditions contribute to the need for adjusted medication dosages. Dose-dependency and time-dependency of drugs further complicate dosage calculations, as some drugs require large doses for efficacy while others are more effective when maintained at lower levels over longer periods.
Ultimately, personalized medicine approaches such as Therapeutic Drug Monitoring (TDM) play a significant role in ensuring optimal therapeutic ranges are achieved for each individual patient, considering their unique characteristics such as age, weight, genetic polymorphism, and comorbid diseases. This personalized approach helps to maximize the benefits of medications while reducing the likelihood of adverse effects.