Pharmacokinetics is the absorption, distribution, metabolism, and excretion (Rosenthal & Burchum, 2018). The pharmacodynamics is what the medication does to the body is vital to prescribing the drugs to patients (Rosenthal & Burchum, 2018). It is essential to understand how the medicines work, the pathophysiology of the bacteria, and different categories of medications to prescribed the right type of drugs in treating patients (Walden University, 2019).

In the dialysis unit, I have encountered a 45-year-old male patient of Hispanic descent who has end-stage renal failure scheduled three times a week of dialysis about three and a half hours per session. I have observed that the patient’s heart rate every dialysis treatment for the past few weeks was elevated, which is above one hundred twenty of pulse rate and elevated blood pressure of above 180/65-200/95. This patient gains about three to five kilograms from his dry weight—the water weight in one to two days. The three to five liters of increased water weight is hard on the body during the pulling of much fluid within three and a half liters within 3 hours, if the patient can tolerate the dialysis treatment.  The patient is non-compliant with fluid management and taking his blood pressure regimen. The patient has no history of diabetes, no heart problems and hypertension in the family.
Furthermore, non-compliance with blood pressure medication is the reason he was diagnosed with end-stage renal failure.

Now during the dialysis treatment, I told the nephrologist about the increased heart rate and hypertension.  The nephrologist then prescribed Atenolol 50 mg by mouth once a day to lower down the heart rate along with other additional blood pressure medications to control his hypertension. The physician changed the blood pressure medication from Lisinopril to Atenolol instead. Atenolol is a beta-blocker blood pressure, water-soluble, slowly metabolized by hemodialysis patients (Rosenthal & Burchum, 2018).  The most valuable used for non-compliant hemodialysis patients (Rosenthal & Burchum, 2018). It has properties that lower down the heart rate and longer half-life that effectively lowers the hypertension with hemodialysis patients to better control his blood pressure (Argarwal, 2015). Atenolol has fifty percent of oral dose is absorbed and peak plasma levels occur in two to four hours after oral ingestion (Argarwal, 2015). The half-life with renal failure is prolonged (Argarwal, 2015). Also, Atenolol 50 mg dose is administered to post-dialysis to adequately control hypertension and lower the heart rate in hemodialysis patients (Argarwal, 2015).

The factors that affected his hypertension are fluid overload, not suitable blood pressure medication, and non-compliance to blood pressure medication. For his increased heart rate, Atenolol has better pharmacokinetics with the patient’s body, which is more effective in lowering the heart rate and blood pressure. According to Rosenthal & Burcham, 2018, Atenolol will take effect after one to two weeks, which is the effectiveness of the drug. Therefore, the patient’s heart rate is within normal limits during dialysis, and blood pressure post-dialysis treatment is below 160/65-140/75, depending on how much fluids were removed during dialysis after two weeks after taking the Atenolol. However, the main side effects of the Atenolol are dizziness, lightheadedness, tiredness, cold extremities, numbness extremities, and blood sugar will decrease for a diabetic patient (Rosenthal & Burchum, 2018). The patient’s chief complaint is the tiredness, dizziness, lightheadedness, numbness in the extremities, but he does not have diabetes.
The plan of care for him is to avoid drinking apple juice or orange juice; it may prevent the full absorption of the medication (Rosenthal & Burchum, 2018). The patient needs to be educated on regularly taking the medication regimen (Rosenthal & Burchum, 2018). The patient is instructed on getting up slowly from lying down to sitting and standing to avoid the dizziness and lightheadedness (Rosenthal & Burchum, 2018). Also, lifestyle changes such as stress reduction, exercise programs, and dietary changes may increase the effectiveness of this medication (Rosenthal & Burchum, 2018). Moreover, the patient needs to check his blood pressure and pulse regularly (Rosenthal & Burchum, 2018). In regards to the numbness and cold extremities, the patient educated on Atenolol’s main side effects. The patient needs to wear warm clothing and stretch the extremities to relieve the symptoms (Rosenthal & Burchum, 2018). The patient needs to comply with maintaining a lower water weight gain to better control blood pressure as well (Lancaster, 1995).

In conclusion, the patient’s change with another blood pressure medication is more effective in controlling his heart rate and blood pressure. Also, the patient’s control of his dry weight or lowered water gain is associated with improving the symptoms of lowering the blood pressure and heart rate. All the education from compliance to the suitable blood pressure medication, lifestyle, and maintaining a dry weight help improved the well being in the long term of the hemodialysis patient  (Argarwal, 2015).

References

Argarwal, R. (2015, November 15). Treating hypertension in hemodialysis improves symptoms seemingly unrelated to

volume excess. Nephrology Dialysis Transplantation, 31(1), 142-149. Retrieved from https://academic-oup-

com.ezp.waldenulibrary.org/ndt/article/31/1/142/2460132

Lancaster, L. (1995). Core Curriculum for Nephrology Nursing. In L. Lancaster (Ed.), Core Curriculum for Nephrology Nursing

(3 ed.). Pittman, NJ: Anthony Jannetti, Inc.

Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced practice providers. St. Louis, MO:

Elsevier.

Walden University (Producer). (2019). Introduction to Advanced Pharmacology [Video file]. Available from Walden University.

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 Case 2019

A 17-year-old African American male was admitted due to psychotic behavior, possibly due to marijuana use, urine drug screen was positive for marijuana. He had no past medical or psychological history; he was adopted, family history was unknown. The psychiatrist ordered Haldol 10 mg by mouth to be given twice daily, as well as other IM antipsychotic medications that were available PRN for agitation. After three days inpatient, the patient developed extra pyramidal side effects (EPS), he was unable to talk, his tongue was swollen, and his neck was stiff. EPS symptoms include; dystonia, akathisia, pseudo-Parkinsonism, tardive dyskinesia, and muscle stiffness (John Hopkins Medicine, 2018).  A treatment for EPS is Cogentin; this medication was on his EMAR, listed under as-needed medications, however he had not received it.  After receiving IM Cogentin, the symptoms resolved. The psychiatrist ordered Cogentin 0.5 mg po to be given twice daily.

Pharmacokinetic and Pharmacodynamic processes

Pharmacokinetics is the study of drug movement throughout the body (Rosenthal & Burchum, 2018). There are four basic pharmacokinetic processes: absorption, distribution, metabolism, and excretion. Pharmacodynamics is the study of the biochemical and physiologic effects of drugs on the body and the molecular mechanisms by which those effects are produced (Rosenthal & Burchum, 2018).

Haldol is prescribed for manifestations of psychotic disorders and Tourette’s syndrome to control tics. Haldol blocks dopamine 2 receptors reducing positive symptoms of psychosis and possibly combative, explosive, and hyperactive behaviors (Stahl, 2017). Oral half-life is approximately 12-38 hours, deconate half-life is approximately 3 weeks. A usual dose is 0.05/mg/kg once or twice a day for adolescents.  This patient weighed 76 kg, so the dose of 10 mg twice daily was high, and without administration of Cogentin lead to EPS.  In the above care the patients age, ethnicity, and behavior are factors that contribute to his overall outcome. Recent research has found that people who use marijuana and carry a specific variant of the AKT1 gene, which codes for an enzyme that affects dopamine signaling in the striatum, are at increased risk of developing psychosis (NIH, 2019). African Americans are 10% more likely to experience serious psychological distress (NAMI, 2020). Adolescents who smoke marijuana regularly may contribute to adult psychosis, it appears to depend on whether a person already has a genetically based vulnerability to the disorder (NIH, 2019).

Tardive dyskinesia is a side effect that develops with prolonged use of antipsychotics; symptoms include grimacing, sucking, and smacking of lips. EPS is another side effect of this medication, all patients taking first or second-generation antipsychotics should have an Abnormal Involuntary Movement Scale (AIMS) completed regularly by their healthcare provider (NAMI, 2020). This drug can cause weight gain, monitor BMI and weight during treatment (Stahl, 2017). Consider monitoring fasting triglycerides and fasting blood glucose during treatment. Haldol may increase the effects of antihypertensive drugs, and it reduces the effects of anticoagulants (Stahl, 2017).

Cogentin is prescribed for extrapyramidal disorders, parkinsonism, and dystonia (Stahl, 2017).  Cogentin diminishes the excess acetylcholine activity caused by the removal of dopamine inhibition when dopamine receptors are blocked. The half-life is 36 hours, although the greatest effect lasts about 6-8 hours (Stahl, 2017).  Cogentin can cause drowsiness if patients are taking pain medications, anti-anxiety medications, or sleeping medications, they may have an increase in sleepiness. Drinking alcohol with Cogentin can cause side effects (Drugs, 2020). Cogentin and other anticholinergic agents may increase serum levels of Digoxin (Stahl, 2017).  This medication can lower the concentration of Haldol and other phenothiazines, causing worsening of schizophrenia symptoms (Stahl, 2017).

Plan of care

A personalized plan of care takes into consideration the patient as a whole, reviewing all pertinent data. Research suggests the AIMS scale should be done regularly by healthcare providers. Nursing staff and the psychiatrist should have started Cogentin on day 1, since the patient was receiving scheduled Haldol and other antipsychotic drugs to control his behavior.  As part of patient care, drug rehab assessment should be ordered. Patient education on the risk of developing psychiatric disorders if he continues to use drugs should be discussed when he is mentally clear.  Recent research suggests that smoking high-potency marijuana every day could increase the chances of developing psychosis by nearly five times compared to people who have never used marijuana (NIH, 2019). Patient education on the importance of medication compliance and the risk if he abruptly stops antipsychotic drugs. Follow up with intensive therapy and psychiatrist or PMHNP for medication management at discharge is essential.

References

Antipsychotics. (2018). Retrieved from https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_Diabetes_Guide/547011/all/Antipsychotics

Drugs.com. (2020). https://www.drugs.com/

Haldol. (2020). Retrieved from https://www.nami.org/Learn-More/Treatment/Mental-Health-Medications/Types-of-Medication/Haloperidol-(Haldol)

Is there a link between marijuana and psychiatric disorders. (2019). Retrieved 2019, from https://www.drugabuse.gov/publications/research-reports/marijuana/there-link-between-marijuana-use-psychiatric-disorders

Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s Pharmacotherapeutics for Advanced Practice Providers. [Adobe Digital Editions version]. Retrieved from http://file:///home/chronos/u-4ce114960615be1ae70e3c90fd868002111bb58d/MyFiles/Downloads/Pharmacotherapeutics%20Book.pdf

Stahl, S. M. (2017). Stahl’s essential psychopharmacology prescriber’s guide (6th ed.). [Adobe Digital Editions version]. Retrieved from http://file:///home/chronos/u-4ce114960615be1ae70e3c90fd868002111bb58d/MyFiles/Downloads/Prescriber_s_Guide_-_Stahl_s_Essential_P.pdf

African American Mental Health. (2020). Retrieved from https://www.nami.org/Find-Support/Diverse-Communities/African-American