NURS 6521 Week 2 Assignment - Pharmacotherapy for Cardiovascular Disorders

Introduction There are many factors that affect the pharmacokinetics and pharmacodynamics of drugs, including age, gender, genetics, ethnicity, and behavior factors. These factors can increase the likelihood of patients developing drug-induced disorders. Age is an important and common factor to consider when prescribing medications. The purpose of this assignment is to synthesize pharmacotherapy for cardiovascular diseases and to explore how aging influences pharmacokinetics, pharmacodynamics, and the patient’s recommended drug therapy. How Age Affects Pharmacokinetics and Pharmacodynamics Altered medication pharmacokinetics and pharmacodynamics result from several changes in human organs that are associated with aging (Drenth-van Maanen, 2019). Because aging delays gastric emptying and decreases intestinal blood flow, gastric acid production, and gut motility, the absorption of drugs is altered. The distribution of drugs is altered due to changes in body composition that are related to aging, which include an increase in body fat and a decrease in total body water. Decreased liver volume, blood flow, and metabolic capacity connected with aging alter the metabolism of drugs. The excretion of drugs is altered due to a decrease in kidney size and glomerular filtration rate in older people. Aging also affects the pharmacodynamics of drugs that act on the cardiovascular system because older people have a decreased sensitivity of β-1 and β-2 adrenergic receptors. This decreases their response to β-agonists and the β- adrenergic blockade. How Changes in the Processes Impact the Patient’s Recommended Therapy The patient’s recommended therapy is significantly impacted due to the changes in the body associated with aging. The reduced clearance of lisinopril, diltiazem, Imdur, metoprolol, hydrochlorothiazide, and digoxin is caused by the effects of impaired renal function related to 3 aging. Prolonged drug half-lives associated with decreased clearance lead to increased drug concentrations (Rochon, 2022). Because of the changes in the β-adrenergic autonomic system responses associated with aging, the hemodynamic response to metoprolol is reduced. Alterations in these processes can lead to undesired effects of the medications including increased antihypertensive effects, dehydration, and digoxin toxicity. Digoxin toxicity is common in patients with poor or worsening renal function, such as elderly patients (Cummings & Swoboda, 2022). It is the most fatal of the undesired effects of the medications. Another notable mention associated with aging that impacts the patient’s drug therapy is also a decline in cognitive status. This can impact the patient’s ability to manage their medications, make decisions, and communicate their beliefs and preferences (Barry & Hughes, 2021). Improvements to the Patient’s Drug Therapy The patient’s cardiac, gastric, renal, and liver functions are fragile due to his pre-existing co-morbid conditions and the natural processes of aging. This can create a challenge when prescribing medications to the elderly. Thus, close monitoring of this patient is essential for his safety due to his increased risk for drug sensitivity given his age. Polypharmacy can result in drug-drug interactions and harmful consequences. As a provider, I would recommend changing and/or discontinuing some of the patient’s medications because there may be a better alternative for treatment, or the medication prescribed may not be necessary. For example, clonidine is an alternative inotrope that can be used in place of digoxin, and it does not require frequent therapeutic monitoring. If the risk of adverse effects outweighs the benefits, I would discontinue the medication and/or find an alternative route. I would also start out with the lowest dosage of his medications and adjust them based on the results of the patient’s lab work and whether the medications are achieving the desired effects. 4 Conclusion The geriatric population is significantly affected by changes in pharmacokinetic and pharmacodynamic processes coupled with the natural aging process. Therefore, their drug therapy must be tailored to meet their needs and achieve the desired effects of their medications. Although a patient may have tolerated their medications well in the past, as they age, the medications may pose a risk for undesirable effects. Medications that act on the cardiovascular system have a significant antihypertensive effect on the elderly because of alterations to receptor stimulation responses and deficiencies in the homeostatic compensatory mechanisms. Thus, close monitoring and alterations to the patient’s drug therapy are critical to ensure the patient’s safety and effectiveness of the therapy. 5 References Barry, H. E. & Hughes, C.M. (2021). An update on medication use in older adults: A narrative review. Curr Epidemiol Rep. 2021; 8(3): 108–115. doi: 10.1007/s Cummings, E.D. & Swoboda, H.D. (2022). Digoxin toxicity. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Drenth‐van Maanen, A. C., Wilting, I., & Jansen, P. A. F. (2019). Prescribing medicines to older people—How to consider the impact of ageing on human organ and body functions. British Journal of Clinical Pharmacology, 86(10), 1921–1930. Rochon, P. A. (2022). Drug prescribing for older adults. UpToDate.