Cardiovascular System Pharmacology Case Study

Background

Pharmacokinetics and pharmacodynamics influence the drug’s effectiveness and availability in the body. Pharmacokinetics describes the drug's movement from entry to elimination points (Mathias, McAleer & Szollosi, 2020). On the other hand, pharmacodynamics entails the drug's action in the body cells (Hill, Kenakin, & Blackburn, 2017). The main pharmacokinetic phases are metabolism, bioavailability, absorption, and elimination. Metabolism begins once a person ingests a pharmacologic agent. Enzymes in the mouth, stomach, and liver break down drugs to metabolites to increase solubility (Currie, 2018). The movement of metabolites across the intestinal mucosal to the circulatory system is absorption (Hill et al., 2017). Once in the circulatory system, blood transports the metabolites to the target cells.

McGavock (2017) describes bioavailability as the rate at which pharmacological molecules get into the bloodstream for transportation to the target sites. Once the metabolites achieve the intended therapeutic actions, they undergo fecal, skin, or renal system elimination from the body.

The impact of age on pharmacology

The major factors that influence the pharmacologic properties of drugs include genetics, gender, body size, muscle mass, ethnicity, age, and behavior factors. Age is particularly a significant factor that influences the pharmacodynamic and pharmacokinetic processes. Older people present with decreased cell function. Most drugs undergo the first-pass effect which affects their concentration before reaching the circulatory system (Koren, Nordon, Radinsky & Shalev, 2019). The pre-systemic metabolism affects the bioavailability of drugs and their subsequent therapeutic effect. However, due to a decrease in the first-pass effect in older people, the concentration of drugs is not affected before reaching the circulatory system. Therefore, the older person is likely to have higher circulatory drug concentrations than a younger person. This implies that the bioavailability of oral drugs is high in an older person (Farinde & Hebdon, 2020). Further, aging leads to a decrease in muscle mass and total body water while body fat increases. These changes contribute to a longer duration of drug action and elevated drug effects.

Changes in the processes

Changes in pharmacokinetics and pharmacodynamics could affect drug therapy in the client. Irrefutably, the decrease in the first-pass effect leads to increased concentration of oral medications. A drug like warfarin may persist in the system, thus, increasing the client’s risk of adverse effect. Warfarin elevates a person’s risk of bleeding. The clinician might need to give the client aspirin to counteract the effect of warfarin (van-den Anker, Reed, Allegaert & Kearns, 2018).

Improving Drug Therapy

Managing pharmacological therapy is a challenging affair, especially in situations where the client is taking several medications. One of the ways to improve drug therapy for the current client is to integrate medication reconciliation into the treatment plan. Medication reconciliation enhances compliance and ensures drugs achieve the targeted outcomes. Reconciliation also helps identify effective medications as well as those that need replacement. Another strategy is to evaluate the client for drug modification opportunities besides maintaining an active medication list. This list helps determine the period over which the client has taken specific medications. The list also creates a platform to constantly review short-term medication to avert the risk of adverse outcomes. This process ensures that medications such as aspirin recommended for the short-term are not taken for extended periods.

Conclusion

Pharmacokinetics and pharmacodynamics are major pharmacological processes that clinicians need to consider before making prescriptions for their clients. These properties are essential when dealing with polypharmacy cases. Some significant factors that influence pharmacodynamics and pharmacokinetics include the client's weight, gender, and age. The physical and chemical nature of drugs could also influence these pharmacological properties. Clinicians can improve pharmacological therapy by maintaining an active medication list and performing drug reconciliation.