Week 1 – Discussion: Pharmacokinetics and Pharmacodynamics
NURS 6521N-36 Advanced Pharmacology
Initial Post
Pharmacodynamics affects not only therapeutic effects but also toxic and adverse effects. Pharmacodynamics depends on the concentration of the drug at the receptor, the response at the receptor, post receptor events within cells and homeostatic mechanisms (Midlöv, 2013). All these parts of pharmacodynamics may be affected with aging. For this discussion post, I will discuss how pharmacokinetics and pharmacodynamics affects the elderly population. I will discuss the case of a 70-year-old female, Mrs. W, who has a diagnosis of Dementia, and other chronic health conditions.
When a patient starts expressing symptoms of agitation or trouble sleeping, or anxiety, the patient may have a standing order for Ativan to be given orally for agitation/anxiety. In most cases, this would work, the patient would calm for several hours. However, in Mrs. W’s case, the opposite outcome was noted. She instead, was experiencing an increase in agitation and exhibiting psychotic behavior such as hallucinations. As the primary nurse, I called the attending physician regarding the patient’s condition, and more Ativan was ordered to be given intravenously. When administered, this second dose didn’t produce any positive outcome for the patient that she ended up having to be in restraints with the “hope” that she would not hurt herself and that she would be clear of her delirium soon.
Benzodiazepines are frequently prescribed for elderly patients living in the community and for those in hospitals and institutions. Their use is more prevalent in women. Prolonged use of benzodiazepines is particularly likely in old age for the treatment not only of insomnia and anxiety, but also of a wide range of nonspecific symptoms.
The elderly population, especially those who are age 70 and older are particularly vulnerable to delirium than those younger due to changes in brain function, multiple general medical problems, polypharmacy, reduced hepatic metabolism of medications, multisensory declines, and brain disorders such as dementia. Polypharmacy, is very common in the elderly, and the possibility of drug-drug interactions must be considered as a cause of agitation. Medications such as benzodiazepines, beta-blockers, selective serotonin reuptake inhibitors (SSRIs), neuroleptics and diphenhydramine can cause more problems. Buspar can be an alternative drug to be given. Other drugs such as Trazodone (second drug of choice) could be given if the patient exhibits anxiety, depression irritability. The drug of choice to treat agitation in the elderly with dementia is Haldol starting with the lowest dose, which should suffice in treating delirium and agitation (Critical Care Nurse, 2012).
Antipsychotics have been the medication of choice in the treatment of delirium. Evidence for their efficacy has come from numerous case reports and uncontrolled trials. A series of controlled trials also showed that antipsychotic medications can be used to treat agitation and psychotic symptoms in medically ill and geriatric patient populations and it demonstrated the clinical superiority of antipsychotic medications over benzodiazepines in delirium treatment (American Psychiatric Association, 2010).
Another problem that could contribute to an elderly patient to showing agitation or psychotic symptoms are Sleep-related disorders, which are common in the general adult population, with 50-70 million Americans affected by chronic sleep disorders (Hartford Institute for Geriatric Nursing, 2017). Given the high prevalence, complexity, and health implications associated with sleep disorders in older adults, increasing attention is now being focused on this topic as a multifactorial geriatric syndrome. While older adults still require as much sleep as younger adults, normal changes in sleep and circadian rhythm with age lead to increased difficulty falling asleep, poorer sleep quality, and more time awake during the night (Hartford Institute for Geriatric Nursing, 2017). In general, use of benzodiazepines in treatment of sleep disturbance in older adults is not recommended. However, non-benzodiazepines such as ramelteon and melatonin receptor agonists may be used to aid older adults in falling and staying asleep. Ramelteon is the preferred drug of choice for patients who are age 70 and older.
The personalize plan of care that could be developed is first line of preventive measure could be including both environmental and supportive interventions, using an orientation protocol or help with visual aids. Many at times these patients do not have their glasses until the next day and they cannot see to understand where they are. For pharmacologic treatment, many doctors use neuroleptic agents such as haloperidol, this would be my first choice of treatment and what I would have done differently. Haloperidol is a potent neuroleptic and psychotropic agent belonging to the group of butyrophenones. It mediates its action through blockade of dopaminergic receptors in the mesocortex and limbic system of the brain. Secondarily, it also has antimuscarinic and anticholinergic properties. Haloperidol has a significant efficacy against delirium and hallucinations, as well as anti-nausea and anti-vomiting properties (Tagarakis et al., 2012). Haldol also has a short half-life and can be administered with repeated doses every 15 to 20 minutes. I have seen it work often and most of the time without the hang over effect that benzodiazepine’s can give a patient.
References
Arcangelo, V. P., & Peterson, A. M. (2013). Pharmacotherapeutics for advanced
practice: A practical approach (3rd ed.). Philadelphia, PA: Lippincott Williams & Wilkins.
American Geriatrics Society Abstracted Clinical Practice Guideline for
Postoperative Delirium in Older Adults. (2015). Journal of the American Geriatrics Society, 63(1), 142-150 9p. doi:10.1111/jgs.13281
American Psychiatric Association (2010). Practice Guideline for the
Treatment of Patients with Delirium. Retrieved from http://psychiatryonline.org/pb/assets/raw/sitewide/practice_guidelines/guidelines/delirium.pdf
Critical Care Nurse (2012). Delirium Assessment and Management.
Retrieved from http://ccn.aacnjournals.org/content/32/1/79.full
Hartford Institute for Geriatric Nursing (2017). Sleep Disorders.
Retrieved from https://consultgeri.org/patient-symptoms/sleep-problems
Midlöv P. (2013). Pharmacokinetics and pharmacodynamics in the elderly.
OA Elderly Medicine. Retrieved from https://monkessays.com/write-my-essay/oapublishinglondon.com/article/621#
Sample Answers
1.
NURS 6521: ADVANCED PHARACOLOGY
WEEK 1 DISCUSSION: PHAARMACOKINETICS AND PHARMACODYNAMICS
Patient case
A patient presented to the ER accompanied by wife and daughter complaining of Left sided tingling and numbness (T/N), Left side facial droop, and Left sided weakness, and some slurred speech that had started approximately 3 to 4 hours prior to ER. Because these symptoms were more likely due to a stroke, the ER physician and the nurse who assessed the patient called for a Brain Attack through the intercom. The call prompted the brain attack team comprising of the Neurology resident, Neurology Charge RN, ER charge nurse, ER physician, ER RN responsible for the patient, and radiology team to be mobilized. Non-contrast CT of the head was done to rule out any hemorrhage.
The CT did not show any intracerebral nor intracranial bleed and the Neurology resident ordered tPA (tissue plasminogen activator) to be given after consulting with his attending physician on-call. The patient was still within the window to give the tPA and the Neurology charge RN gave the medication as ordered. As per protocol, the patient was closely monitored for any adverse drug reactions (ADRs) for 2 hours until he was transferred to the stroke unit for further management and observation. One of the ADRs of tPA is bleeding and patients who receive this medication should not get any antiplatelet or anticoagulants for the next 24 hours until another CT or MRI confirm that there is no hemorrhage in the brain. According to Wang et al., (2015) tPA is the only drug approved by the United States Food and Drug Administration to treat ischemic stroke. It is a serine protease that catalyzes the conversion of plasminogen to plasmin, which then dissolves the blood clot that produced the stroke, and to be effective tPA must be administered intravenously within the first 3-4 hours of the event, owing to the risk of hemorrhagic transformation (HT) after ischemic stroke.
Pharmacokinetic and Pharmacodynamics Processes
Per protocol, all patients who are admitted to the stroke unit should receive Aspirin within 24 hours to further reduce brain damage from a blood clot. If a patient is not able to swallow, ASA can be administered rectally. For this particular patient, he was not able to swallow so was a candidate for a rectal ASA which was already preordered. The floor nurse unfortunately gave the rectal ASA before another CT was done to confirm if there was hemorrhage in the brain or not. A CT that was supposed to be done showed that indeed the patient has had a bleed with a midline shift. His condition deteriorated and was sent to ICU where he was intubated.
Personalized Plan of Care
According to Rosenthal & Burchum (2018), although closely following the guidelines is desirable, we must always take into account that our patients may not fit well into these guidelines and that individualized care is always best. One of the contributing factors to this patient receiving ASA was that it was in the preorder set. The nurse gave the ASA as ordered but should have waited for the second CT to be done before doing so. After this incident, ASA was not preordered anymore due the mix-up and miscommunication. All residents were not allowed to preorder ASA as part of the stroke protocol but have to wait for the results of the CT from the Radiologist before doing so.
References
Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced
practice providers. St. Louis, MO: Elsevier
Wang, W., Li, M., Chen, Q., & Wang, J. (2015). Hemorrhagic transformation after tissue
plasminogen activator reperfusion therapy for ischemic stroke: Mechanisms, models, and biomarkers. Mol Neurobiol, 52(3), 1572-1579. DOI: 10.1007/s12035-014-8952-x
2.
Week 1 Discussion
COLLAPSE
Patient scenario
Mrs. Smith is a 62-year-old Caucasian female who was admitted for Alcohol Detox. This patient has been drinking 750ml of vodka daily for more than 10 years. She has a history of hypertension, GERD, with drawl seizures, and liver cirrhosis.
Patient Factors
There are four phases of pharmacokinetics- absorption, distribution, metabolism, and excretion. (Rosenthal, L. D., & Burchum, J. R. (2018) (pg.17). The patient mentioned above has several factors that may affect the pharmacokinetics of medications. Factors that must be considered when prescribing this patient medication are her age, liver disease, GERD and anemia. “The physiologic changes that occur during the aging process leads to several alterations in the absorption, distribution, metabolism, and excretion of drugs, understanding lower starting doses and increased dosing intervals in older adults is very important for the healthcare provider.” (Sera, L., & Uritsky, T. (2016). Liver disease is also a major factor when prescribing medications to this patient because “liver disease affects drug pharmacodynamics, which can either reduce or increase the effect of a drug and can lead to serious adverse drug reactions.” (Pirmohamed, M. (2019). Antacids used to treat the GERD can also cause issues with the absorption of medications by altering the ph balance in the stomach. (Rosenthal, L. D., & Burchum, J. R. (2018) (pg.35).
Plan of Care
This patient should have labs ordered to check her liver, kidneys, ammonia level, B-12 level, and blood counts and rechecked daily. To prevent seizures a benzodiazepine should be started to prevent seizure activity. A short-acting medication should be used such as Ativan due to her age and to also prevent oversedation which could be caused if a long-acting medication was used due to liver disease. Vital signs should be monitored every 4 hours to watch for an increase in vital signs. The patient should remain on fall and seizure precautions due to her medications, history, and age.
References
Pirmohamed, M. (2019). Prescribing in liver disease. Medicine, 47(11), 718–722. https://doi-org.ezp.waldenulibrary.org/10.1016/j.mpmed.2019.08.012
Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced practice providers. St. Louis, MO: Elsevier.
Sera, L., & Uritsky, T. (2016). Pharmacokinetic and pharmacodynamic changes in older adults and implications for palliative care. Progress in Palliative Care, 24(5), 255–261. https://doi-org.ezp.waldenulibrary.org/10.1080/09699260.2016.1192319
3.
Week 1 Discussion
COLLAPSE
I was presented with a case involving a 14 year-old Caucasian boy who suffered child abuse so severe his case made the national news. This young male suffered physical and emotional abuse, neglect and torture, which contributed to harsh pathophysiological changes likely due to the trauma. Although he is 14 years old, he is only as tall as the average 9- or 10- year old. He presents with medical concerns, such as cardiovascular problems, stunted growth, and insomnia. Other factors that may have influenced pharmacokinetic and pharmacodynamic processes of this patient include his age and BMI, behavioral problems such as poor impulse control, severe aggression, social isolation and poor cognitive development. He also presents with psychiatric manifestations of high anxiety and depression.
This patient is considered to be a part of “Special Populations” due to his age (Rosenthal & Burchum, 2018, p. 6). A personalized plan of care based on this patient’s history include considerations to his age, BMI, pathophysiological changes, presenting medical symptoms and physiological state. He first must be separated from his abuser(s) and placed in a nurturing environment. Because his nervous system is being subjected to effects of extreme and chronic stress, the autonomic nervous system, hypothalamic-pituitary-adrenal (HPA-axis), and sleep/arousal systems have also been affected (Elbers, Rovnaghi, Golianu, & Anand, 2017).
To avoid potentially overprescribing or inappropriate prescribing of medications, I will begin with prescribing one psychotropic medication which treats two conditions: depression and anxiety. For example, Aripiprazole (Abilify) is a second-generation atypical antipsychotic (SGA), classified as a dopamine partial agonist, and Helps in both mixed mania and depression. Aripiprazole has a safer and more favorable profile than other SGAs, however, it may be less effective than some (Rosenthal & Burchum, 2018, p. 242). Another drug to consider is Risperidone (Risperdal), an atypical antipsychotic which is prescribed for behavioral disturbances and improves cognitive function in children and adolescents (Rosenthal & Burchum, 2018, p. 241). If mood dysregulation is not improved, the use of an adjunctive medication, such as Valproate may be added. Lithium is not considered for this patient due to its notable side effects of renal impairment, arrhythmia, and cardiovascular changes. The Food and Drug Administration (FDA) approves the use of Valproate for mania and mixed episodes as an adjunctive therapy. Before starting treatment, platelet count and liver function tests will be determined (Hatta, 2016). His cardiovascular status, along with BMI must be measured when choosing the most beneficial psychotropic medication. Lastly, to combat effects of insomnia, Melatonin will be added to patient’s regimen.
Psychotropic medications which have not been approved by the FDA for the use in children/adolescents will not be considered.
References
Elbers, J., Rovnaghi, C., Golianu, B., & Anand, K. (2017). Clinical profile associated with adverse childhood experiences: the advent of nervous system dysregulation. Children, 4(11), 98. doi: 10.3390/children4110098
Hatta, K. (2016). Antipsychotic adjunctive therapy to mood stabiliser should be continued for 6 months after remission of a manic episode. Evidence Based Mental Health, 20(1), 28–28. doi: 10.1136/eb-2016-102532
Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced practice providers. St. Louis, MO: Elsevier.
