Pharmacodynamics And Pharmacokinetics Essay

Pharmacodynamics And Pharmacokinetics Essay

Case scenario

I encountered J.M, a 26 years old African female previously diagnosed with generalized anxiety disorder. She has been on alprazolam 0.5mg once a day for six years. She does not attend the psychiatric clinic because she feels she is okay. She states that she has been experiencing panic and anxiety attacks associated with dizziness, drowsiness, nausea, and vomiting. She at times takes alprazolam 4mg to relieve her symptoms but ends up feeling dizzy and drowsy. She is also taking clarithromycin due to pneumonia. Atorvastatin 40mg at night due to hyperlipidemia. Lactulose syrup 15mls three times a day due to constipation. She is obese, leads a sedentary lifestyle, smokes tobacco, and takes alcohol.

Pharmacodynamics And Pharmacokinetics Of Alprazolam

Alprazolam is a benzodiazepine FDA approved for anxiety disorders and panic attacks. It is an off-label treatment of pre-menstrual syndrome, insomnia, and depression (Ait-Daoud, et al, 2018). However, alprazolam has subject to misuse for recreational purposes due to its side effects. Pharmacokinetics is the action of the body on the drug. They are; absorption, distribution metabolism, and excretion. Alprazolam is absorbed two hours after drug intake with 90% bioavailability in the system. It binds to serum protein by 75% for quick distribution in the system. The liver enzymes cytochrome P450 metabolizes alprazolam (Fuhr, et al, 2021). Alprazolam metabolites excretion is in the kidneys through urine. Alprazolam half-life is 13hours in healthy adults.

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Pharmacodynamics is the effect of the drug on the body. They are; therapeutic effects, side effects, and adverse effects. Alprazolam binds to the GABA receptor that mediates its effects. GABA-A receptors have five other receptors that include one alpha-1, two beta-2, and two gamma-2 (Wilbraham, et al, 2020). the expected effects are muscle relaxation, ataxia, sedation, coordination of motor functions, memory, and anticonvulsant. The drug side effects are dizziness, drowsiness, insomnia, headache, GI symptoms, and muscle weakness.

Factors Affecting The Pharmacokinetics Of Alprazolam

Factors that affect drug pharmacokinetics are; age, gender, weight, drug co-administration, and pathophysiological changes. Age affects drug elimination in the body. For example, alprazolam plasma half-life is 11-13 hours in healthy adults and 15-16 hours in elderly patients. Drug co-administration with ketoconazole and clarithromycin inhibits the metabolism of alprazolam in the liver. Pathophysiological changes are hepatotoxicity and liver diseases. They alter the liver’s enzymes that metabolize the drug, hence, inhibiting alprazolam metabolism (Fuhr, et al, 2021). Obese patients have a slower absorption rate, distribution rate, and metabolism rate. However, they have a longer plasma half-life of 21 hours. Factors affecting pharmacokinetics in this patient are; obesity, co-administration of clarithromycin, and liver diseases due to excessive alcohol intake.

Factors Affecting Pharmacodynamics Of Alprazolam

Factors affecting pharmacodynamics are; drug dosage, substance use, genetics, and drug receptors. Drug overdose worsens the side effects and may lead to death or coma. Alprazolam administration at a lower dose does not achieve its therapeutic effect. Taking the alprazolam together with alcohol and other substances worsens the side effects. It may lead to death or coma (Wilbraham, et al, 2020). Abrupt drug withdrawal without psychiatric nurse consultation may lead to severe withdrawal symptoms such as convulsions. Factors affecting pharmacodynamics for this patient are drug overdose, use of alcohol, and tobacco smoking.

Personalized Care Plan For This Patient

I would enroll the patient in the psychiatric clinic to monitor her progress and drug adherence. I would educate the patient on the need to take the prescribed drug dose to avoid experiencing adverse effects. I would also explain the expected side effects and the danger signs. I would switch clarithromycin to amoxicillin because it inhibits the metabolism of alprazolam. I would counsel the patient to stop taking alcohol and smoking tobacco to avoid adverse effects.

Pharmacodynamics And Pharmacokinetics Of Alprazolam

Alprazolam is a benzodiazepine with brand names such as Xanax, Niravam, and Xanax XR. It is FDA approved for the treatment of anxiety disorders and panic attacks. It is an off-label treatment of pre-menstrual syndrome, insomnia, and depression (Ait-Daoud, et al, 2018). However, alprazolam has subject to misuse for recreational purposes due to its side effects. It is a psychoactive drug that acts on the GABA-A receptors; alpha, gamma, epsilon, delta, and beta. These GABA-A receptors bind with a benzodiazepine to mediate muscle-relaxing effects, sedation, anticonvulsant activity, anxiolytic effects, motor coordination, memory, sedation, and calming effect (Ait-Daoud, et al, 2018). The adult dose of alprazolam is 0.25 to 0.5mg orally every eight hours. Dosage increase should be gradual, two to three-day intervals at a maximum of 4mg per day.

Pharmacokinetics Of Alprazolam

Pharmacokinetics is the action of the body towards the drug. It includes drug absorption, distribution metabolism, and excretion. Alprazolam has a faster absorption rate of two hours after drug intake with 90% bioavailability in the system. It binds to serum protein especially albumin by 75% for quick distribution in the system. Its metabolism takes place in the liver by the liver enzymes cytochrome P450 (Fuhr, et al, 2021). Alprazolam metabolites excretion is in the kidneys through urine. Alprazolam half-life is 13hours in healthy adults.

Factors Affecting The Pharmacokinetics Of Alprazolam

Factors affecting drug pharmacokinetics are age, gender, weight, drug co-administration, and pathophysiological changes. Age affects drug elimination in the body. For example, alprazolam plasma half-life is 11-13 hours in healthy adults and 15-16 hours in elderly patients. Drug c0-administration such as ketoconazole and clarithromycin inhibits the metabolism of alprazolam in the liver. Pathophysiological changes such as hepatotoxicity and other live diseases alter the liver’s enzymes that metabolize the drug, hence, inhibiting alprazolam metabolism (Fuhr, et al, 2021). Obese patients have slow absorption, distribution, metabolism, and have a longer plasma half-life of 21 hours compared to normal healthy adults.

Pharmacodynamics Of Alprazolam

Pharmacodynamics is the effect of the drug on the body. This includes the positive effects, the side effects, and the adverse effects. Alprazolam binds to several sites in the central nervous system. The GABA receptor mediates its effects. GABA-A receptors have five receptors such as one alpha-1, two beta-2, and two gamma-2 (Wilbraham, et al, 2020). These receptors produce different effects on the human body. The alpha-1 receptor produces muscle relaxing, ataxic, anxiolytic, and sedative effects of alprazolam. The beta-2 receptor coordinates the motor functions, restores memory, and has an anticonvulsant effect. The gamma receptors produce a calming effect on the body. Therefore, alprazolam is effective in treating depressive mood due to its ataxic effects, panic attack, and anxiety disorder due to its calming effects. However, the drug has side effects on the nervous system that include dizziness, drowsiness, insomnia, headache, GI symptoms, and muscle weakness.

Factors Affecting Pharmacodynamics Of Alprazolam

Factors affecting the pharmacodynamics are drug overdose, abrupt withdrawal, use of drugs and substances, and dose reduction. Drug overdose worsens the side effects and may lead to death or coma. Alprazolam administration at a lower dose does not achieve its therapeutic effects. Taking the alprazolam together with alcohol and other substances worsens the side effects. It may lead to death or coma (Wilbraham, et al, 2020). Abrupt drug withdrawal without psychiatric nurse consultation may lead to severe withdrawal symptoms such as convulsions.

Conclusion

Alprazolam is a benzodiazepine, FDA approved for the treatment of anxiety disorders and panic attacks. Alprazolam has a faster absorption with 90% bioavailability and a plasma half-life of 11 hours. it has well-tolerated side effects Pharmacodynamics

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. 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. Photo Credit: Getty Images/Ingram Publishing 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. Pharmacodynamics And Pharmacokinetics Essay

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. 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.

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To Prepare Review the Resources for this module and consider the principles of pharmacokinetics and pharmacodynamics. Reflect on your experiences, observations, and/or clinical practices from the last 5 years and think about how pharmacokinetic and pharmacodynamic factors altered his or her anticipated response to a drug. Consider factors that might have influenced the patient’s pharmacokinetic and pharmacodynamic processes, such as genetics (including pharmacogenetics), gender, ethnicity, age, behavior, and/or possible pathophysiological changes due to disease. Think about a personalized plan of care based on these influencing factors and patient history in your case study. Pharmacodynamics And Pharmacokinetics Essay

some links Rosenthal, L. D., & Burchum, J. R. (2021). Lehne’s pharmacotherapeutics for advanced practice nurses and physician assistants (2nd ed.) St. Louis, MO: Elsevier. Chapter 1, “Prescriptive Authority” (pp. 1–3) Chapter 2, “Rational Drug Selection and Prescription Writing” (pp. 4–7) Chapter 3, “Promoting Positive Outcomes of Drug Therapy” (pp. 8–12) Chapter 4, “Pharmacokinetics, Pharmacodynamics, and Drug Interactions” (pp. 13–33) Chapter 5, “Adverse Drug Reactions and Medication Errors” (pp. 34–42) Chapter 6, “Individual Variation in Drug Response” (pp. 43–45) American Geriatrics Society 2019 Beers Criteria Update Expert Panel. (2019). American Geriatrics Society 2019 updated AGS Beers criteria for potentially inappropriate medication use in older adults. Journal of the American Geriatrics Society, 67(4), 674–694. doi:10.1111/jgs.15767 American Geriatrics Society 2019 updated AGS Beers criteria for potentially Pharmacodynamics And Pharmacokinetics Essay inappropriate medication use in older adults by American Geriatrics Society, in Journal of the American Geriatrics Society, Vol. 67/Issue 4. Copyright 2019 by Blackwell Publishing. Reprinted by permission of Blackwell Publishing via the Copyright Clearance Center. This article is an update to the Beers Criteria, which includes lists of potentially inappropriate medications to be avoided in older adults as well as newly added criteria that lists select drugs that should be avoided or have their dose adjusted based on the individual’s kidney function and select drug-drug interactions documented to be associated with harms in older adults. Drug Enforcement Administration. (2021). CFR – Code of Federal Regulations Title 21. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=1300 This website outlines the code of federal regulations for prescription drugs. Drug Enforcement Administration. (n.d.-a). Mid-level practitioners authorization by state. Retrieved May 13, 2019 from http://www.deadiversion.usdoj.gov/drugreg/practioners/index.html This website outlines the schedules for controlled substances, including prescriptive authority for each schedule. Drug Enforcement Administration. (2006). Practitioner’s manual. Retrieved from http://www.legalsideofpain.com/uploads/pract_manual090506.pdf This manual is a resource for practitioners who prescribe, dispense, and administer controlled substances. It provides information on general requirements, security issues, recordkeeping, prescription requirements, and addiction treatment programs. Drug Enforcement Administration. (n.d.-b). Registration. Retrieved February 1, 2019, from Pharmacodynamics And Pharmacokinetics Essay https://www.deadiversion.usdoj.gov/drugreg/index.html This website details key aspects of drug registration. Fowler, M. D. M., & American Nurses Association. (2015). Guide to the code of ethics for nurses with interpretive statements: Development, interpretation, and application (2nd ed.). American Nurses Association. This resource introduces the code of ethics for nurses and highlights critical aspects for ethical guideline development, interpretation, and application in practice. Institute for Safe Medication Practices. (2017). List of error-prone abbreviations, symbols, and dose designations. Retrieved from https://www.ismp.org/recommendations/error-prone-abbreviations-list This website provides a list of prescription-writing abbreviations that might lead to misinterpretation, as well as suggestions for preventing resulting errors. Ladd, E., & Hoyt, A. (2016). Shedding light on nurse practitioner prescribing. The Journal for Nurse Practitioners, 12(3), 166–173. doi:10.1016/j.nurpra.2015. Pharmacodynamics And Pharmacokinetics Essay

References

Ait-Daoud, N., Hamby, A. S., Sharma, S., & Blevins, D. (2018). A review of alprazolam use, misuse, and withdrawal. Journal of addiction medicine, 12(1), 4. Pharmacodynamics And Pharmacokinetics Essay

Fuhr, L. M., Marok, F. Z., Hanke, N., Selzer, D., & Lehr, T. (2021). Pharmacokinetics of the CYP3A4 and CYP2B6 Inducer Carbamazepine and Its Drug–Drug Interaction Potential: A Physiologically Based Pharmacokinetic Modeling Approach. Pharmaceutics, 13(2), 270.

Wilbraham, D., Berg, P. H., Tsai, M., Liffick, E., Loo, L. S., Doty, E. G., & Sellers, E. (2020). Abuse Potential of Lasmiditan: A Phase 1 Randomized, Placebo‐and Alprazolam‐Controlled Crossover Study. The Journal of Clinical Pharmacology, 60(4), 495-504. Pharmacodynamics And Pharmacokinetics Essay