Pharmacokinetics and Pharmacodynamics Discussion

 Discussion – Week 1

Patient Case

The patient was an 89-year old female admitted to home care with a primary diagnosis of congestive heart failure or CHF. History included myocardial infarction within the past 5 years and atrial fibrillation. The patient had shortness of breath with minimal exertion, cough when lying down, hypertension, and fluid retention.  Edema was present in bilateral lower extremities that presented in a range of 2+ to 3+ pitting.  The patient did not have diabetes or kidney failure which helped with getting heart failure stabilized.  The patient lived with her husband in an independent living facility but had been non-compliant with her medications as she was unsure when what, or why she was taking any of her medications.  The patient also had acquired tremors that were making medication set up for the week difficult.  The patient main insurance was Medicare.  Insurance can be the reason a medication can or cannot be used.  Can the patient pay for a high-cost medication that may have better results than a lower costing medication?  In this case, the patient was able to afford whatever medication was prescribed.  As a home care nurse, it was our job to monitor how her medications are affecting the diagnosis of the patient, pharmacodynamics, and how the drug is affected when it enters the body or pharmacokinetics.  Not every patient will have the same reaction to the same drug.


Factors that may have influenced pharmacodynamics and pharmacokinetics processes for this patient may have included the diagnosis of a-fib and hypertension with a past myocardial infarction.  A rhythmic medication would need to be added to help with irregular heart rhythm due to a-fib.  This patient did not have renal failure, but this is something to be watched as it usually does accompany heart failure patients.  Another factor to look for would be how well the body is absorbing and excreting the medication.  Are there any Gastrointestinal diagnosis, renal failure, or impaired liver function associated with the patient (Lainscak, et al. 2016)?  Any impairments in the body could affect the correct outcome for the patient with the use of their medication.  There is an existing gray area when it comes to the use of medication in the elderly.  What will cause more harm than good continues to be researched every day (American Geriatrics Society, 2019).

Plan of Care

The patient main diagnosis of cardiac heart failure would lead me to a diuretic to remove excess fluid build-up and lower blood pressure.  Furosemide is the first medication that I would add to the plan, starting with a low dose of 20mg in am and increasing if needed as the patient did not have a renal function diagnosis. Potassium levels would need to be monitored if potassium were not added to the medication list. The patient had high blood pressure as well as atrial fibrillation so I may suggest medication such as Metoprolol Succinate ER with a low dose of 25mg 2x daily.  This would help both the blood pressure and provide help with heart rhythm. If the patient had been a diabetic, I would not have used a beta-blocker, but an ace-inhibitor would be a better choice (The diagnosis of atrial fibrillation would also need to be addressed.  Plavix/Clopidogrel usually 75mg daily is what I would prescribe to address blood clots. Plavix is an antiplatelet drug.  Cholesterol levels should also be checked to see if medication such as Atorvastatin should be added on to help reduce the bad cholesterol, helping to reduce any further myocardial infarctions. Patients with past heart issues should have Nitroglycerin refilled yearly to have around for chest pain.  The tremors of this patient are an issue as holding onto the medication and getting into her mouth was a struggle.  A tremor medication such as Primidone (Thornton, 2019). could be added to help get them under control.  Proper education on exercise, what medications she is taking, and why she is taking them, fluid intake, elevating legs, and labs to monitor kidney and liver function would be needed.






Lainscak, M., Vitale, C., Seferovic, P., Spoletini, I., Trobec, K.C., Rosano, G.M.C., (2016).

Pharmacokinetics and pharmacodynamics of cardiovascular drugs in chronic heart

failure. International Journal ofCardiology. Vol.224 Pp 191-198. Retrieved from:

Thornton, P. (2019). Medications for Heart Failure (Congestive Heart Failure). Harvard Health

            Publications. Retrieved from:

American Geriatrics Society 2019 Beers Criteria Update Expert Panel. (2019). American

Geriatrics Society 2019 updated AGS Beers criteria for potentially inappropriate

medication use in older adults. Journal of the American Geriatrics Society. 67(4), 674-

694. doi:10.1111/jgs.15767.

Retrieved from:

Good post! I agree that the patient should have medication adjustments to help improve the patient’s overall health. Females have been known to not seek early treatment when it pertains to heart conditions. Cardiac disease causes more female deaths than all the cancers combined (Fallon, 2019). The typical symptoms of an MI that most women believe to be true, often do not occur in females. The clutching of the chest and shooting left arm pain are not the symptoms experienced by most females (Fallon, 2019). I would add to the plan cardiac rehab for the patient. Studies have proven the effect of cardiac rehab with patients suffering from cardiac illness has proven effective, especially when continuing a home cardiac rehab program. The cardiac rehab would direct the patient on proper exercises and most offer long term programs for patients to continue the therapy. A recent study followed over 19,000 cardiac patients over two years and concluded that the patients who attended formal cardiac rehab and continued the program showed significant progress over the patients that did not attend the formal rehab (Sjolin, Back, Nilsson, Schiopu, & Leosdottir, (2020). 


Fallon, C. K. (2019). Husbands’ hearts and women’s health: Gender, age, and heart disease in twentieth-century America. Bulletin of the History of Medicine, 93(4), 577-609.


Sjolin, I., Back, M., Nilsson, L., Schiopu, A., & Leosdottir, M. (2020). Association between attending exercised-based cardiac rehabilitation and cardiovascular risk factors at one-year post myocardial infarction. PloS One, 15(5), e0232772.

Discussion: Pharmacokinetics and Pharmacodynamics

As an advanced practice nurse assisting physicians in the diagnosis and treatment of disorders, it is important to not only understand the impact of disorders on the body, but also the impact of drug treatments on the body. The relationships between drugs and the body can be described by pharmacokinetics and pharmacodynamics.

Pharmacokinetics describes what the body does to the drug through absorption, distribution, metabolism, and excretion, whereas pharmacodynamics describes what the drug does to the body.

Photo Credit: Getty Images/Ingram Publishing

When selecting drugs and determining dosages for patients, it is essential to consider individual patient factors that might impact the patient’s pharmacokinetic and pharmacodynamic processes. These patient factors include genetics, gender, ethnicity, age, behavior (i.e., diet, nutrition, smoking, alcohol, illicit drug abuse), and/or pathophysiological changes due to disease.

For this Discussion, you reflect on a case from your past clinical experiences and consider how a patient’s pharmacokinetic and pharmacodynamic processes may alter his or her response to a drug.

To Prepare
  • Review the Resources for this module and consider the principles of pharmacokinetics and pharmacodynamics.
  • Reflect on your experiences, observations, and/or clinical practices from the last 5 years and think about how pharmacokinetic and pharmacodynamic factors altered his or her anticipated response to a drug.
  • Consider factors that might have influenced the patient’s pharmacokinetic and pharmacodynamic processes, such as genetics (including pharmacogenetics), gender, ethnicity, age, behavior, and/or possible pathophysiological changes due to disease.
  • Think about a personalized plan of care based on these influencing factors and patient history in your case study.
By Day 3 of Week 1

Post a description of the patient case from your experiences, observations, and/or clinical practice from the last 5 years. Then, describe factors that might have influenced pharmacokinetic and pharmacodynamic processes of the patient you identified. Finally, explain details of the personalized plan of care that you would develop based on influencing factors and patient history in your case. Be specific and provide examples.

By Day 6 of Week 1

Read a selection of your colleagues’ responses and respond to at least two of your colleagues on two different days by suggesting additional patient factors that might have interfered with the pharmacokinetic and pharmacodynamic processes of the patients they described. In addition, suggest how the personalized plan of care might change if the age of the patient were different and/or if the patient had a comorbid condition, such as renal failure, heart failure, or liver failure.

Note: For this Discussion, you are required to complete your initial post before you will be able to view and respond to your colleagues’ postings. Begin by clicking on the “Post to Discussion Question” link, and then select “Create Thread” to complete your initial post. Remember, once you click on Submit, you cannot delete or edit your own posts, and you cannot post anonymously. Please check your post carefully before clicking on Submit!



Patient C is 81y male with COPD, AFIB, and HTN with a new onset of bronchitis. The patient medicine list includes propranolol, albuterol nebs, warfarin, and Levaquin. The patient takes his morning medicine with his nebs after breakfast. He just started taking his albuterol in the morning instead of the evenings like he use to. He takes his blood pressure with his automatic monitor and puts it in his journal. He has recently noticed that his blood pressure has been on an upward trend. He has also noticed that he has a lot of bruising on his legs and on his hips. He has a home INR machine and his recent INR was higher than it had been even though his coumadin dose is unchanged. He said that he normally eats a salad of dark greens everyday but since he has not felt “good” that he has not had any fresh produce.

Propranolol, a beta blocker, when taken with albuterol, a beta-agonist, can reduce the efficacy of both medications since they have opposite effects on the body. Propranolol can cause narrowing of the airways. Albuterol opens up the airways (Ajimura,,2018)..

Warfarin is an anticoagulant that reduces the formation of clots. As a competitive antagonist vitamin K can reverse the effects of coumadin (Rosenthal & Burchum p. 381) . Foods that are high in vitamin K are leafy greens, kale, brussels sprouts and plums.

Levaquin is a fluoroquinolone that can be used to treat pneumonia, kidney infections, bronchiectasis and sinusitis. Warfarin becomes attached to protein binding sites in the body (Rosenthal & Burchum p. 17). When warfarin is taken with Levaquin the warfarin becomes dislodged from the protein binding sites . There is a subsequent loss of gut flora that produces vitamin K (Liaqat,, 2019). This sequence of events leads to an increase in INR when the combination of the two medications are taken concomitantly.

This patient has been calling in his INR to the coagulation group and they dose his coumadin accordingly. He said that he normally eats leafy greens but has stopped. The vitamin K that he was getting has stopped and allowed for an increase in available coumadin increasing his INR (Liaqat,, 2019) . I would educate him on the importance of maintaining the same diet consistently as his INR is measured weekly. The Levaquin should be changed to cefixime which has shown to not change the INR (Liaqat,, 2019). This patient is taking his albuterol as a scheduled medication. He may  need an inhaled steroid like budesonide or Qvar for maintenance COPD symptoms and the albuterol used as prn. The patient should not take the albuterol with the propranolol (Ajimura,,2018). The BP issue that he is having could be the result of taking the two competing medications together.





Ajimura, C. M., Jagan, N., Morrow, L. E., & Malesker, M. A. (2018). Drug Interactions With Oral Inhaled

Medications. The Journal of Pharmacy Technology : jPT : Official Publication of the Association of Pharmacy Technicians34(6), 273–280.

Liaqat, A., Khan, A. U., Asad, M., & Khalil, A. H. (2019). Effect of Quinolones Versus Cefixime on

International Normalized Ratio Levels After Valve Replacement Surgery with Warfarin Therapy. Medicina (Kaunas, Lithuania)55(10), 644.

Rosenthal, L. D., & Burchum, J. R. (2021). Lehne’s pharmacotherapeutics for advanced practice nurses and physician assistants. St. Louis, MO: Elsevier.