66-year Old Caucasian Pharmacokinetics and Pharmacodynamics Scenario

Pharmacokinetics and Pharmacodynamics

             Today, the basic principles of pharmacokinetics and pharmacodynamics continue to play a leading role in healthcare and in informing decisions made by care providers. Nutt & Nestor (2018) asserts that pharmacokinetics provide a detailed overview of the duration taken by medication before absorption, its mechanism action, and subsequent excretion. Moreover, pharmacokinetics also studies the overall distribution of metabolized drugs after absorption by the enterocytes lining of the small intestines. Pharmacodynamics, on the other hand, is the study of the link between drug concentration, its effect, duration of action, and possible side effects on users (Counterman & Lawley, 2021). Knowledge of these basic tenets is, therefore, critical since it raises the awareness of healthcare providers regarding the physiological effects of different medications.. This discussion will feature a reflection of my personal experience with a 66-year old Caucasian male client with a history of Generalized Anxiety Disorder (GAD) and hypertension.

Scenario

             RP is a 66-year old male with a history of Generalized Anxiety Disorder (GAD) and hypertension. He presents to the ER accompanied by his wife after exhibiting signs consistent with myocardial infraction (MI). However, a routine EKG soon ruled out this initial speculation.  Nevertheless, RP seemed deeply disturbed, anxious and in anguish; complaining of chest tightness appearing worried.  He was slightly overweight, at 210 Lbs., and admitted having four to five beers each evening.

                          RP registered a score of 27 in the Hamilton Anxiety Rating Scale (HAM-A), indicative of severe anxiety. He also reported experiencing nausea, frequent headaches, blurred vision, and trouble sleeping. His wife also revealed that she recently noticed a sudden change in RP ever since he started treatment for GAD two month prior. Changes noted comprised; RPs behavior, impulsivity, unnecessary agitation, evidence of suicidal tendencies, and irritability.  Yet, the patient managed to remain well orientated and composed during his clinical presentation. RP’s vital signs were also normal. His wife presented the following list of prescribed medications:

  • Clonidine 0.1 mg
  • Crestor 20 mg
  • Metformin 75 mg
  • Tofranil 25mg

Factor’s Influencing Patient’s Pharmacokinetic and Pharmacodynamics Processes                 

                 Prescribed medications are normally subjected to a complex pharmacokinetic process that typically ends with their excretion. When taken orally, absorption occurs in the stomach and continues in the ileum. Further absorption occurs here and infusion into the liver in preparation for distribution. However, the patient’s advanced age is an important factor to consider given glomerular filtration rates (GLR) diminish with age and may, therefore, have a negative impact on excretion of leftover byproducts  (Mungall & White, 2019). Furthermore, caution should be exercised when combining Trofanil 25 mg and Clonidine 0.1 mg. According to Tiwari (2018), imipramine hydrochloride may increase the effects of Central Nervous System (CNS) depressants and blood pressure medication, especially when combined with alcohol. RP’s recent bout of anxiety and other accompanying symptoms listed above are consistent with side effects of imipramine hydrochloride. Trofanil (Imipramine) has a Food and Drug Administration (FDA) black box warning since it increases risks of suicidal behavior, unusual behavior changes, irritability, heightened anxiety, and mood changes.  Additional side effects of imipramine hydrochloride also include blurred vision, lightheadedness, and frequent headaches.

Personalized Plan of Care               

Currently, Psychiatric Units play a vital role in ensuring patients receive appropriate care for their respective conditions while also addressing developing concerns outside of their immediate sphere of psychiatric concerns. In this case, RP’s recent spell of anxiety, panic attacks, suicidal tendencies, and behavioral changes are likely linked to his recent Trofanil prescription. The personalized plan of care should, therefore, feature a change in the choice of antianxiety while ensuring the new medication selected is also capable of block gamma-aminobutyric acid (GABA) within the brain to reduce anxiety. Zoloft 50 mg, a common first-line selective reuptake inhibitor (SSRI), is an ideal choice for RP’s drug modification. It is effective in managing common GAD symptoms, with minimal side effects, and may help RP regain control over their behavior and life. However, regular follow up is necessary to monitor patient’s progress and their response to the newly prescribed medication.

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