Write a 2- to 3-page paper that addresses the following:

• Explain how the factor you selected might influence the pharmacokinetic and pharmacodynamic processes in the patient from the case study you were assigned.
• Describe how changes in the processes might impact the patient’s recommended drug therapy. Be specific and provide examples.
• Explain how you might improve the patient’s drug therapy plan and explain why you would make these recommended improvements.

Case Study 

BN is a 74-year-old African American male who is seeing his PCP because he noticed when he woke up that his “heart was not beating right; it feels like it is going to slow.” He denies chest pain, SOB, N/V. He notes feeling dizzy earlier in the day. 6 weeks earlier his PCP started him on Diltiazem CD to further lower his BP to goal. His Metoprolol was lowered at that time as well from 75 mg to 50 mg BID. His PCP recommends he be admitted to the hospital.

Upon presentation to the hospital:

PMH:

• HTN x 7 years
• Type II DM
• CAD s/p angioplasty 2 years ago
• MI 3 years ago
• EF = 60%
• PVD s/p left femoral to posterior bypass
• Hx of A Fib x 4 years

Medications:

• Digoxin 0.25 mg QD KCl 40 mEq QD Vitamin C 500 mg QD
• Diltiazem CD 180 mg QD ASA EC 325 mg QD Vitamin E 400 IU QD
• Metoprolol 5- mg BID Warfarin 5 mg QD Ibuprofen 200 mg 2 tabs prn headache
• Lisinopril 20 mg QD Famotidine 20 mg QHS Multivitamin QD
• Imdur 30 mg QD Lantus 26u QHS Ca++/Vit D 500mg/200 IU BID
• HCTZ 12.5 mg QD Humalog 8u with meals

PE:

• BP 110/50 Pulse 38 bpm Resp 14/min
• Rest of physical exam unremarkable

Labs:

• K+ 6.9 WBC 5,800/mm3
• Na+ 135 Hct 35%
• Cr 1.9 Dig 2.78
• BUN 35 INR 2.3
• Gluc 102

Understanding How Drugs Work in Older Adults

As people get older, they become more likely to have various health issues like high blood pressure, diabetes, and heart problems. Because of this, treating these conditions often requires using several different medications. However, as people age, their bodies change, and this can affect how drugs are processed and how they work. This article looks at how age influences how drugs affect a patient named BN, focusing on their body’s processes for handling and responding to medication.

Factors That Influence How Drugs Work in Older Patients

One important factor is age, which affects how drugs move through the body and how the body responds to them. Pharmacokinetics involves how drugs move into, through, and out of the body, including how they’re absorbed, distributed, broken down, and removed. In older adults, there can be significant changes in these processes, some of which are very important for doctors to consider. For example, as people age, their bodies may not break down and get rid of drugs as quickly as they used to. This means that if someone takes a medication for a long time, the amount of the drug in their body can build up to potentially harmful levels. Additionally, aging can affect how drugs are absorbed in the body, potentially delaying when they start working. For instance, Lisinopril, a medication used for heart health, might take longer to start working in older adults because their bodies absorb it more slowly. Aging can also change the body’s composition, leading to more body fat and less water. This can alter how some drugs are distributed throughout the body and how long they stay in the system, as seen with drugs like metoprolol.

Another important aspect is pharmacodynamics, which is how drugs interact with the body. In older patients, the effectiveness of a drug might vary compared to younger people. This can be due to a range of factors, including how drugs interact with receptors in the body, how the body responds to those interactions, and any changes in organs that affect drug action. Older adults may also be more sensitive to certain side effects of medications, especially those with anticholinergic effects. These effects are common in drugs used for conditions like depression, high blood sugar, high blood pressure, and urinary problems, and it’s important to monitor older patients closely when they’re taking these medications.

How Changes in Drug Processes Affect Recommended Treatments

The changes that come with aging, such as higher stomach pH, reduced stomach surface area, and slower drug elimination, can affect how drugs work and how they should be used in older patients like BN. For example, Lisinopril might be absorbed differently in the intestines of older adults, affecting how well it works. Aging can also slow down the body’s ability to break down certain drugs in the liver, increasing the risk of harmful effects. Diltiazem, for instance, might not be broken down as quickly in older adults, potentially leading to toxicity.

Older adults may also have reduced kidney function, which affects how drugs are eliminated from the body. This can increase the risk of toxicity for drugs like digoxin and Lisinopril. Changes in body composition, such as more fat and less water, can also impact how drugs move through the body. For example, metoprolol and digoxin might not distribute as well in the body of an older patient like BN, which could have significant effects on their treatment.

Improving Treatment Plans for Older Patients

To ensure the best outcomes for patients like BN, healthcare providers need to carefully select the right drugs and doses, monitor their effectiveness and side effects, and educate patients about their medications. For BN, adjustments to the treatment plan might include lowering the dose of diltiazem due to changes in how it’s processed in the body and closely monitoring its effectiveness. Similarly, digoxin should be used cautiously and possibly at lower doses due to reduced kidney function in older adults. Metoprolol and Lisinopril may also require lower doses because of changes in kidney function, with doses adjusted based on how well they work. Educating patients about potential side effects is crucial for their safety.

In conclusion, age can have a big impact on how drugs work in the body, especially in older adults. Changes in how drugs are processed and how the body responds to them can affect treatment outcomes. By carefully selecting and monitoring medications, healthcare providers can help older patients like BN achieve the best possible health outcomes.

NURS 6512N Week 3 – Rachel Adler Conversation Concept Lab Shadow Health

Pharmacodynamics and Pharmacokinetics in Older Patients

            The geriatric populations are at an increased risk for developing multiple comorbidities, including hypertension, diabetes mellitus, and cardiovascular diseases. Consequently, the treatment of this disease requires multiple medications. The mechanism and metabolism of the medications administered may shift among this patient as aging results in changes in physiology which impact the drug’s pharmacokinetics and pharmacodynamics processes. In patients’ cardiovascular diseases and other comorbidities, drug-to-drug interactions are a factor that may also affect the pharmacokinetic and pharmacodynamics process. This paper discusses how age as a factor in patient BN in the case study influences the pharmacodynamics and pharmacokinetic process, how the change influences the drug therapy, and how to improve the patient’s drug therapy.

Factors affecting pharmacodynamics and pharmacokinetic process in the patient

Age is a factor that will influence the pharmacodynamics and pharmacokinetic process of patient BN. Pharmacokinetics is a drug’s movement in the body, including absorption, distribution, metabolism, and excretion. In elderly patients, significant changes may occur, some of which are more clinically relevant. Aging causes a considerable decrease in the metabolism and excretion of many drugs. A reduction in metabolism and excretion rate may cause toxicity because the concentrations of chronically used medications increase by 5 to 6 half-lives. According to Thürmann (2020), age reduces the small-bowel surface area, slows gastrointestinal motility, and increases gastric Ph. This may result in delayed absorption and onset of action. For example, the onset of action for Lisinopril may be affected because of the decreased absorption and bioavailability. Aging also causes an increase in body fat and reduces total body water. This is associated with increased volume distribution and increased elimination of half-lives for some drugs, such as metoprolol.

Pharmacodynamics is the study of the drug’s interaction with the body. In geriatric patients, the efficacy of the same drug concentrations on different action sites may vary compared to those in younger populations. The changes observed are attributed to drug-receptor interactions, adoptive homeostatic responses, post-receptor events, and pathologic changes in different organs (Thürmann, 2020). There is also increased sensitivity to anticholinergic drug effects. Medications such as antidepressants, antihyperglycemics, antidepressants, antihypertensive, and urinary antimuscarinic agents have an anticholinergic effect, and as such, patients using such drugs must be monitored frequently.

Impact of the change in processes of the recommended drug therapy

As Thürmann (2020) discusses, aging is associated with increased gastric Ph, reduced stomach surface area, and reduced excretion of drugs. These changes impact the pharmacokinetic and pharmacodynamics processes of the recommended drug therapy for patient BN. For example, in the case of Lisinopril, the drug’s absorption level may increase in the small intestines but may reduce its bioavailability. Aging also decreases the overall hepatic metabolism for specific medications, decreasing the clearance rate to approximately 30 to 40%. As a result, there is an increased risk for higher toxic effects. For example, the hepatic metabolism of diltiazem may be reduced, which may increase the risk of toxicity

Aging is also associated with reduced renal elimination of some medications. The decrease in renal elimination has clinically significant implications for patient toxicity levels. For example, the renal elimination of digoxin and Lisinopril will reduce significantly. There is also an increased fat and decreased total water mass in old patients (Andres et al., 2019). This may affect the diffusion of certain medications. In the case of patient BN, the distribution and uptake of the metoprolol and digoxin may reduce, which may result in significant clinical implications. Aging is associated with changes in sensitivity to different drug concentrations, which may affect the pharmacodynamics process. For example, in inpatient BN, the response to diltiazem may differ from that of a younger patient.

Improving the patient’s drug therapy plan

Different approaches may help optimize the drug therapy plan for patient BN. Providers must choose the best drugs and correct dosage for older patients while monitoring for effectiveness and toxicity and patient education about adverse health outcomes (Sleder et al., 2015). For patient BN, some adjustments may be made. For instance, the diltiazem dosage may be decreased because of its decrease in mechanism and increased volume in distribution. The efficacy of the dose must be monitored, and if the slightest efficacy, then the drug dosage should not be increased. Digoxin must also be used cautiously because of its reduced renal elimination, which may increase toxicity. In addition, its clearance level also increases. Therefore, the dosage should be adjusted to start with at least 0.125mg and adjusted according to the response (Sleder et al., 2015). Metoprolol and Lisinopril also have reduced renal elimination and thus should be administered at lower dosages, and the dose increased until the lowest efficacy is achieved. In addition, educating the patients about the possible side effects of the medications is essential. With the drug therapy plan adjustment, optimal health outcomes for patient BN will be achieved.

Conclusion

In summary, age is a factor that affects pharmacodynamics and pharmacokinetic processes. Older patients experience pathologic changes in body organs, which affect the drug’s mechanism and metabolism. This is affected by certain factors, including increased gastric Ph, reduced bowel surface area, increased body fat, reduced total body water, reduced renal elimination, and reduced metabolism. Therefore, medications among the elderly must be first administered at lower dosages while monitoring the efficacy, toxicity, and side effects.

 References

Andres, T. M., McGrane, T., McEvoy, M. D., & Allen, B. F. S. (2019). Geriatric    pharmacology. Anesthesiology Clinics, 37(3), 475–492. https://doi.org/10.1016/j.anclin.2019.04.007

Sleder, A. T., Kalus, J., & Lanfear, D. E. (2015). Cardiovascular Pharmacokinetics,    pharmacodynamics, and pharmacogenomics for the clinical practitioner. Journal of Cardiovascular Pharmacology and Therapeutics, 21(1), 20–26. https://doi.org/10.1177/1074248415590196

Thürmann, P. A. (2020). Pharmacodynamics and pharmacokinetics in older adults. Current Opinion in Anaesthesiology, 33(1), 109–113. https://doi.org/10.1097/aco.0000000000000814