Rosenthal & Burchum (2017) describe pharmacokinetics as the study of drug movement throughout the body and pharmacodynamics as the study of the biochemical and physiological effects of drugs on the body and the molecular effects by which those effects are produced. NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics. In lay terms, Pharmacokinetics can be viewed as what the body does to the drug, absorbing it, distributing it, metabolizing it and excreting it, while pharmacodynamics can be viewed as what the drug does to the body when it interacts with receptors and brings about changes. These characteristics of drugs are influenced by various parameters of the patient such as age, gender, size and genetics. At times the drugs we administer do not produce the expected effects due to these characteristics. NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics
My discussion is focused on a patient I had in an Adolescent psych unit. The pt was a 16-year-old African American female, with a history of major depressive disorder with suicidal ideation. She was admitted to our unit after suffering acute catatonia which was thought to have been induced by her prescription medication. Catatonia is a fascinating motor syndrome associated with mood and thought disorders (Benarous, 2018). Manifestations include muscular rigidity, posturing, negativism and stereotyped mannerisms. The onset of this condition was acute, and it was not well understood why the she was presenting with these symptoms. NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics.
Pharmacodynamic and Pharmacokinetic processes
Numerous factors influence the pharmacodynamics and pharmacokinetics of drugs often times leading to unexpected side effects and idiosyncratic reactions NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics. The patient in case was a 16-year-old who had not been on her drugs for long. It is often said that children and adolescents are not just smaller versions of adults; certain characteristic render them different such that the drugs that we use in adults may not suffice just reducing the dose for them. For one, their livers and kidneys may not be fully developed so that they may not metabolize and eliminate drugs in the same way adults do. Moreover, their enzymes may not be functioning as well as those of adults. Furthermore, their size makes it such that their BSA/Vol ratio is different from that of adults meaning that the drug is dissolving in a different volume of fluid with pharmacokinetic implications. NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics To top it all, the genetics of each individual may make them react differently to any drug.
Individualized plan of care
In many psychopharmacology scenarios, the adage “start low and go slow” is golden. The patient in this scenario had been started on Lexapro and Ativan when her catatonia developed. Her drug levels should be determined while the medications reviewed. NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics. Alternative drugs should be started slowly while she was being monitored, till she stabilizes. There are numerous benzodiazepines and SSRIs and sometimes people may react poorly to one drug and do better to another drug in the same class. In the meantime symptomatic treatment with other benzodiazepines and neuromuscular relaxants were carried out. NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics.
Rosenthal, L., & Burchum, J. (2017). Lehne’s Pharmacotherapeutics for Advanced Practice Nurses and Physician Assistants-E-Book. Elsevier Health Sciences.
Benarous, X., Raffin, M., Ferrafiat, V., Consoli, A., & Cohen, D. (2018). Catatonia in children and adolescents: New perspectives. Schizophrenia research, 200, 56-67.
I worked in the ER at a hospital where we had a lot of psychiatric admissions which included baker acts from children, adults, and seniors. I have admitted adults who have been in a catatonic state and patients who have experienced tardive dyskinesia from taking the psychiatric medication Haldol. To counteract these side effects the physicians have to take into consideration the patient’s history, age, and medications that they are currently on. “Catatonia, a neuropsychiatric condition proposed to be associated with gamma-aminobutyric acid (GABA) hypoactivity due to its robust response to benzodiazepines, has been described as a withdrawal syndrome in case reports but is not a well-recognized phenomenon”(Meyen & Reddy, 2018) NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics.
Since children are constantly growing and their body is developing there is a concern on how drugs are metabolism. “Since there are rapid changes in size, body composition, and organ function that occur during the first year of life, clinicians as well as pharmacokinetics and toxicologists are presented with challenges in prescribing safe and effective doses of therapeutic agents”(Moudgil et al., 2019) NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics. Psychiatric medications that are used on children and adolescents have different pharmacokinetic clinical responses than adults based on continuous growth.
Meyen, R., Acevedo-Diaz, E. E., & Reddy, S. S. (2018). Challenges of managing delirium and catatonia in a medically ill patient. Schizophrenia Research, 197, 557–561. https://doi.org/10.1016/j.schres.2018.02.019
Moudgil, A., Dharnidharka, V. R., Feig, D. I., Warshaw, B. L., Perera, V., Murthy, B., Roberts, M. E., Polinsky, M. S., & Ettenger, R. B. (2019). Phase i study of single‐dose pharmacokinetics and pharmacodynamics of belatacept in adolescent kidney transplant recipients. American Journal of Transplantation, 19(4), 1218–1223. https://doi.org/10.1111/ajt.15236 NURS 6521 week 1 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. NURS 6521 week 1 Discussion: 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.
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 NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics.
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.
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. NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics.
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. NURS 6521 week 1 Discussion: Pharmacokinetics and Pharmacodynamics.