Cardiovascular System: Pharmacokinetics and Pharmacodynamics Essay

Introduction

Advanced practice nurses have to be ready for numerous responsibilities in the workplace and rely on the evaluations and examinations of different factors, including risk factors, individual patient issues, and behavioral aspects. The impact of the pharmacokinetics and pharmacodynamics cannot be ignored in the creation of a patient treatment plan for patients with stroke and hypertension history because these processes help to investigate drug absorption, distribution, metabolism, and elimination (Spinler, 2017). In this paper, a particular case of patient CB will be analyzed in terms of the factor of ethnicity that may influence the pharmacokinetic and pharmacodynamic processes of the currently prescribed drugs.

Case Introduction

In this case, a patient has a history of strokes, hypertension, hyperlipidemia, and diabetes. The combination of these diseases may provoke the progress of severe cardiovascular diseases. Therefore, pharmacokinetics and pharmacodynamics of every drug have to be investigated and used in regard to such factors as ethnicity. It is supposed for the patient to be African American.

Pharmacokinetics and Pharmacodynamics of Drugs

1. Glipizide (10 mg daily) is an anti-diabetic drug of the sulfonylurea class. It works as a blocker of potassium channels in beta cells and results in insulin encouragement and lowering blood glucose. Gastrointestinal absorption is fast and complete. However, it can be delayed by food intake by 30 minutes. Being a protein-bound substance, glipizide is usually distributed in the extracellular fluid. It is characterized by hepatic metabolism and urine excretion in 10-24 hours. Its half-life is about 2-4 hours. Side effects may include nausea, diarrhea, dizziness, or itching.
2. HCTZ (25 mg per day) is a diuretic medication to treat hypertension. It causes loss of water and potassium and increases serum uric acid. The absorption is about 50-60% and observed in the upper jejunum or duodenum. Protein-bound at 68%. This drug is not metabolized but eliminated without changes in the kidney fast. Its half-life is between 5 and 14 hours. Weakness, nausea, vomiting, and muscle pain may be observed as possible side effects.
3. Atenolol (25 mg per day) is a beta-blocker to prevent cardiovascular diseases and manage hypertension. It is used to bind beta receptors and promote sympathetic stimulation that results in cardiac output. It is absorbed in the gastrointestinal tract and exerted in the feces without changes. Minimal hepatic metabolism is observed. Half-life is 6-7 hours. Protein-bound at 6-16%. Side effects are constipation, dry mouth, and confusion.
4. Hydralazine (25 mg) is used to treat heart problems and hypertension by the possibility to facilitate the work of blood vessels and increase oxygen supply. It is 90%-absorbed in the gastrointestinal tract. Hepatic metabolism is observed through polymorphic genetic acetylation. Urine excretion is in the form of metabolites. Half-life is 3-7 hours. Protein-bound at 87%. Side effects are nausea, vomiting, and anxiety.
5. Simvastatin (80 mg per day) is used to decrease the level of lipids. This antilipemic agent helps to reduce the level of cholesterol. Its absorption is up to 85%. 95% bound to plasma proteins. Metabolism is in the liver. 3 hours of half-life. Elimination of an oral dose is in the urine and the feces. Side effects are muscle pain, confusion, and fever.
6. Verapamil (180 mg per day) is a calcium channel blocker that treats hypertension. It is absorbed by 90%. Protein-bound at 90%. Its elimination is 70% in the urine and about 16% in the feces. Its half-life is 2-7 hours. Its side effects include dizziness and constipation.

Glipizide increases the effect of verapamil. It is also suggested to combine verapamil and simvastatin to avoid heart problems. HCTZ may oppose the effects of glipizide by increasing the level of glucose in the blood and making diabetes treatment less effective. The combination of HCTZ and atenolol positively influences therapy for patients with hypertension.

Ethnicity and Drugs

Ethnicity plays a critical role in affecting pharmacokinetic and pharmacodynamic processes. Low plasma renin levels, genetic polymorphisms, and high levels of angiotensin II in African Americans are directly associated with the metabolism and absorption of antihypertensive drugs (Barranger & Hadley, 2017). There are no significant differences in the drug metabolism of the chosen medications for African Americans (Harman et al., 2013).

Still, African Americans poorly respond to ACE inhibitors and beta-blockers, and they better absorb calcium blockers. It is necessary to remember that diuretics are not required for patients with diabetes and hyperlipidemia due to the risk of insulin resistance (Barranger & Hadley, 2017; Barron & Willey, 2017). Mr. CB is a male African American, the consumption of Hydralazine and Verapamil can potentially be associated will less significant effects on addressing hypertension and hyperlipidemia.

Changes and Improvements in Treatment

Statins help to predict lipid levels increase. Still, a cholesterol absorption inhibitor may be offered instead of Simvastatin as an alternative (Savarese et al., 2013). The consumption of Glipizide is recommended with no changes. The metabolic effects of using Glipizide in African American patients are positive. Atenolol can be ineffective in addressing the patient’s hypertension with the focus on the associated hyperlipidemia and T2D.

The use of ACE inhibitors and angiotensin receptor blockers is preferable for patients with hypertension and T2D (Eshtehardi et al., 2015). However, African Americans may not respond to ACE inhibitors. In this case, the prescription of Teveten is recommended. It should be consumed in combination with hydrochlorothiazide, and its dosage should be adjusted to prevent side effects.

Conclusion

Ethnicity plays an important role in affecting pharmacokinetic and pharmacodynamic processes. Drugs should be carefully chosen regarding patients’ ethnicity and side effects. Some drugs for treating cardiovascular diseases can be less effective when proposed for African Americans. Depending on the absorption, metabolism, excretion, and distribution of drugs, it is important to plan the pharmacological treatment for patients and think about possible alternatives.

References

Barranger, K., & Hadley, D.E. (2017). Hypertension.. In V.P. Arcangelo, A.M. Peterson, V. Wilbur, & J.A. Reinhold (Eds.), Pharmacotherapeutics for advanced practice: A practical approach (4^th ed.) (pp. 257-272). Ambler, PA: Lippincott Williams & Wilkins.

Barron, J., & Willey, V.J. (2017). Hyperlipidemia.. In V.P. Arcangelo, A.M. Peterson, V. Wilbur, & J.A. Reinhold (Eds.), Pharmacotherapeutics for advanced practice: A practical approach (4^th ed.) (pp. 275-286). Ambler, PA: Lippincott Williams & Wilkins.

Eshtehardi, P., Pamerla, M., Mojadidi, M. K., Goodman-Meza, D., Hovnanians, N., Gupta, A.,… Zolty, R. (2015). Addition of angiotensin-converting enzyme inhibitors to beta-blockers has a distinct effect on Hispanics compared with African Americans and whites with heart failure and reduced ejection fraction: A propensity score–matching study. Journal of Cardiac Failure, 21(6), 448-456.

Harman, J., Walker, E. R., Charbonneau, V., Akylbekova, E. L., Nelson, C., & Wyatt, S. B. (2013). Treatment of hypertension among African Americans: The Jackson heart study. The Journal of Clinical Hypertension, 15(6), 367-374

Savarese, G., Costanzo, P., Cleland, J. G., Vassallo, E., Ruggiero, D., Rosano, G., & Perrone-Filardi, P. (2013). A meta-analysis reporting effects of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in patients without heart failure. Journal of the American College of Cardiology, 61(2), 131-142.

Spinler, S.A. (2017). Pharmacotherapy for venous thromboembolism prevention and treatment, stroke prevention in atrial fibrillation, and thromboembolism prevention with mechanical heart valves.. In V.P. Arcangelo, A.M. Peterson, V. Wilbur, & J.A. Reinhold (Eds.), Pharmacotherapeutics for advanced practice: A practical approach (4^th ed.) (pp. 863-886). Ambler, PA: Lippincott Williams & Wilkins.