Pharmacokinetics and Pharmacodynamics

Pharmacokinetics and Pharmacodynamics

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 Reply button to complete your initial post. Remember, once you click on Post Reply, you cannot delete or edit your own posts and you cannot post anonymously. Please check your post carefully before clicking on Post Reply!

I had a recent clinical experience where a patient of mine was sensitive to medications. She had recently had high blood pressure in the 200’s and acute kidney failure. She was given IV hydralazine and labetalol in the emergency room. She had a reaction to the medication and her heart rate dropped into the 20’s and she became unresponsive. The emergency room staff performed chest compressions and administered to the patient, and she was transferred to the ICU.

A case study writes about adverse effects of hydralazine and notes “Hydralazine was chosen for its antihypertensive effect and 2 mg were administered intravenously (IV). Within a brief period of time (30-45 sec) the patient developed a profound bradycardia from 52-10 beats/min occasioned by premature ventricular contractions (PVCs)” (Wehner & Romanauskas, 1981). A different case study notes a similar adverse effect of labetalol, “She was thought to have an anaphylactoid reaction and was treated intravenously with fluids, diphenhydramine (50 mg), and methylprednisolone (250 mg), without initial improvement. While urinating in the bedpan, she developed bradycardia and hypotension, with a pulse of 30/min and a blood pressure of 60/40. Trendelenburg’s position and 2 L of normal saline were needed to restore her blood pressure to normal, although her bradycardia resolved spontaneously” (Ferree, 1986).

This patient had orders to receive hydralazine IV to maintain a blood pressure of 140/80 so that she could have a kidney biopsy. “Most patients who undergo renal biopsy have hypertension, but hypertension is almost never considered a single or leading indication for biopsy” (Stompór & Perkowska-Ptasińska, 2020).

I diluted the hydralazine and pushed it over 10 minutes minimum and monitored the patient closely. I checked her blood pressure 15-30 minutes after administration and monitored her heart rate. She did not have any adverse reaction to the hydralazine when I administered it. I instructed the patient to use her call light button if she had any strange reactions or felt odd. I kept the physician updated on the patient’s blood pressure and heart rate throughout the night. The patient was able to transfer to a medical-surgical floor for a lower level of care.

References

FERREE, C. E. (1986). Apparent Anaphylaxis from Labetalol. Annals of Internal Medicine, 104(5), 729–730. https://doi-org.ezp.waldenulibrary.org/10.1059/0003-4819-104-5-729_2

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