NRNP_res_6566

NRNP 6566: Main Discussion Purpose The purpose of this discussion post is to describe how an advanced practice nurse would alter the medication dose of Bactrim in a patient with chronic renal failure. The Role of the Kidneys in Pharmacokinetics Excretion, a component of pharmacokinetics, describes a drugs elimination through kidney filtration and waste removal via urine (Sakai, 2008). The most common organ of drug excretion is the kidneys. Drugs that are not excreted by the kidneys will continue to be recirculated in the bloodstream, potentially leading to toxic drug levels and adverse effects (Doogue & Polasek, 2011). A patient’s creatine clearance and GFR are utilized to estimate how fast blood is filtering through the kidney (Doogue & Polasek, 2011). Thus, the creatinine clearance or GFR can be utilized for renal dosing of medications. Excretion of Bactrim occurs via the urinary tract (Wolters Kluwer, 2020). Therefore, a patient with chronic renal failure will exhibit prolonged excretion of Bactrim (Doogue & Polasek, 2011). Bactrim is composed of the compounds TMP and SMX and is available in single concentration; 80mg TMP/400mg SMX, or double strength; 160mg TMP/800mg SMX (Wolters Kluwer, 2020). The half -life elimination of TMP is 6-11 hours, and SMX is 9-11 hours. Since Bactrim can be dosed every 12 hours (Kenmic & Coleman, 2020), and available in a double concentration strength, renal failure has the potential to lead to higher steady state levels of Bactrim. When there are higher steady state levels of Bactrim, toxicity signs of nausea and vomiting, dizziness, headache, mental depression, confusion, thrombocytopenia, uremia, loss of appetite, colic, drowsiness, or bone marrow depression can occur (Kemnic & Coleman, 2020). Since TMP has the ability to reduce renal potassium excretion (Nickels, Jones, & Stead, 2012), a coexisting renal failure places the patient at risk for hyperkalemia. Dosing guidelines for Bactrim based upon creatinine clearance (CrCl) include: a CrCl greater than 30mL/min=no change in dose, a CrCl of 15-30 mL/min=reduction in dose by 50%, a CrCl less that 15mL/min=do not prescribe (Kemnic & Coleman, 2020). Monitoring for Bactrim Effects with Renal Failure An APRN will screen the patient for potential contraindications, or dosing adjustments for the use of Bactrim. This includes a history of renal failure, prescribed potassium sparing medications, allergies to sulfa, weight, and age (Wolters Kluwer, 2020). The APRN will also want to obtain a serum chemistry to reflect renal function and potassium level prior to prescribing, and periodically while taking Bactrim with associated renal failure This study source was downloaded by from CourseH on :04:49 GMT -05:00 (Wolters Kluwer, 2020). Since the patient with renal failure will potentially have higher steady state levels of Bactrim, education of signs of toxicity should be provided to the patient. If the patient exhibits any signs of toxicity, has hyperkalemia, or worsening of renal function, Bactrim should be discontinued (Wolters Kluwer, 2020). References Doogue, M. P., & Polasek, T. M. (2011). Drug dosing in renal disease. The Clinical biochemist. Reviews, 32(2), 69– 73. %20glomerular&text=Some%20active%20drug%20moieties%20are,eGFR %20to%20estimate%20drug%20clearance. Kemnic, T.R., & Coleman, M. (2020). StatPearls: Trimethoprim Sulfamethoxazole. Nickels, L. C., Jones, C., & Stead, L. G. (2012). Trimethoprim-sulfamethoxazole-induced hyperkalemia in a patient with normal renal function. Case reports in emergency medicine, 2012, . Sakai, J. B. (2008). Practical pharmacology for the pharmacy technician. Jones & Bartlett Learning. Chapter 3, “Pharmacokinetics: The Absorption, Distribution, and Excretion of Drugs” (pp. 27– 40). Wolters Kluwer. (2020). Lexicomp (5.7.1). [UpToDate.Inc] This study source was downloaded by from CourseH on :04:49 GMT -05:00