The purpose of this discussion is to describe a patient case from my clinical practice within the last five years and talk about factors that may have influenced pharmacokinetic  and pharmacodynamic processes of the patient.

Discussion: Pharmacokinetics and Pharmacodynamics

The purpose of this discussion is to describe a patient case from my clinical practice within the last five years and talk about factors that may have influenced pharmacokinetic  and pharmacodynamic processes of the patient. I will also explain the personalized care plan that was developed for this patient based on these factors and their history.

Pharmacokinetics can be defined as the study of drug movement throughout the body, meaning what the body does to the drug (Rosenthal & Burchum, 2021, p. 13). There are four basic concepts that go along with pharmacokinetics: absorption, distribution, metabolism, and excretion (Phamacology – Pharmacokinetics (Made Easy), 2015). This is how we as practitioners know how to maximize the benefits a drug will have on a person and minimize the harm it may cause an individual. We must know the proper dosage of a medication based off of the patient and patient’s medical history that may delay absorption, metabolism, or excretion of the drug and find the right balance to elicit the proper response. If this is not done properly, then harm could be done to the patient if the balance is off, such as too much medication is given or not enough to benefit the client. Pharmacodynamics can be defined as the study of the biochemical and physiologic effects of drugs on the body and the molecular mechanisms in which those effects are produced, or what the drug does to the body (Rosenthal & Burchum, 2021, p. 22). This is important to understand as a practitioner so we are prescribing the minimal dose needed of a medication to take the desire effect on the patient and how much the medication can be increased in order to elicit the desired effect without causing harm.

A patient that stands out in my mind is a 23-year-old male that was a frequent flier of the emergency department who often came in highly intoxicated, hypoglycemic, sometimes suicidal, and at times unresponsive due to both hypoglycemia and his chronic alcohol abuse issues. This patient and his father both frequented our emergency department, although his father passed away a few months before the patient in this case scenario, he also eventually succumbed to his  alcoholism. The patient was well known to us as having type 1 diabetes and was supposed to be on Novolin R, Lantus (of which he admitted he hadn’t taken in years) and also on 50mg of Zoloft for depression and anxiety. The patient suffered from alcoholism and would binge drink, which would interfere with his diabetes and his insulin regimen, if he remembered to take it, or at times he would become overconfident and just take a random dose of short-acting insulin as he was drinking without checking his sugars. Therefore, we often saw him in different stages hypo or hyperglycemia depending on if he was drinking or just not taking his insulin properly. The patient also suffered from alcohol-induced hepatitis and impaired renal function at his age due to his failure to control his diabetes and his binge drinking for many years.

Insulin’s purpose is to regulate glucose metabolism and this is done by binding to insulin receptors on muscles and adipocytes and by lowering blood glucose by facilitating the cellular re-uptake of  glucose while also inhibiting the output of glucose from the liver (“Insulin, regular (HumuLIN R, myxredlin),” 2021). Insulin does have a short half-life of 86-141 minutes when given subcutaneously and the peak time may vary depending on the brand he was using. Insulin is metabolized within the liver, kidneys, and fat and 30-80% is excreted within the urine, meaning those with impairment to the liver or kidneys, such as with this patient who had a history of hepatitis and impaired kidney function with chronic elevated creatinine and BUN levels, he was unable to properly metabolize or excrete the insulin he was giving himself, causing his blood sugar levels to be off and hypoglycemia to occur due to alcoholism (Pastor, Conn, Teng, O’Brien, Loh, Collins, MacIsaac, & Bonomo, p. 188).

As the care team, we had to try and come up with ways to care for this patient and his chronic issues taking into account his patient factors, such as young age, being a male and more at risk for hereditary alcoholism, improper diabetic diet, alcohol abuse, and his risky behaviors of too much or too little insulin without checking his sugars to verify the dose needed. We consulted endocrinology many times for this patient, heavy patient education on the proper insulin dosages, long and short acting insulin and also the need to check his sugars multiple times a day, had a dietician see the patient as well and attempted to get the patient into a rehab facility. The patient was not agreeable to changing his lifestyle and thought he was “invincible”. This patient did eventually pass away from his lifestyle choices and other co-morbidities at a young age.

As clinicians, we need to do more for our patients to advocate for them from the beginning and start screening our patients from a young age especially when there is a family history of alcoholism. We also need to be monitoring our patient’s medications more closely, as this patient should not have been so free with his insulin and had better education and guidelines from day one, maybe it may have engraved a habit in him. This is why it is so important for practitioners to also understand the pharmacokinetics and dynamics of a medication, in someone like this patient, who needed different monitoring and dosing of his insulin due to his liver and renal impairments and inability to properly metabolize and excrete the insulin.

References

Insulin, regular (HumuLIN R, Myxredlin) | Davis’s drug guide. (n.d.). Davis’s Drug Guide Online + App | DrugGuide.com. https://www.drugguide.com/ddo/view/Davis-Drug-Guide/109058/all/insulin_regular?q=humalog

Insulin, regular (HumuLIN R, Myxredlin). (2021). Davis’s Drug Guide Online. https://www.drugguide.com/ddo/view/Davis-Drug-Guide/109058/all/insulin_regular?q=humalog

Pastor, A., Conn, J., Teng, J., O’Brien, C. L., Loh, M., Collins, L., MacIsaac, R., & Bonomo, Y. (2017). Alcohol and recreational drug use in young adults with type 1 diabetes. Diabetes Research and Clinical Practice, 130, 186-195. https://doi.org/10.1016/j.diabres.2017.05.026

Pharmacology – Pharmocokinetics (Made Easy) [Video]. (2015). YouTube. http://www.youtube.com/watch?v=NKV5iaUVBUI&t=16s

Rosenthal, L., & Burchum, J. (2021). Lehne’s Pharmacotherapeutics for nurse practitioners and physician assistants (2nd ed.). Elsevier.