Renal Pharmacy Management: Study Notes

Kidney Anatomy and General Functions

• The kidneys are two bean-shaped organs, each about the size of a fist. They are located in the back on either side of the spine.

• Healthy kidneys:

  • Clean waste products from the blood by making urine.

  • Balance certain elements in the blood (e.g., sodium, potassium, calcium).

  • Make hormones that control blood pressure and red blood cells.

Function of the Kidney

• Remove waste products from the body.

• Remove drugs from the body.

• Balance the body's fluids.

• Release hormones that regulate blood pressure.

• Produce an active form of vitamin D that promotes strong, healthy bones.

• Control the production of red blood cells.

What is Kidney Failure?

• Kidney (renal) failure means kidneys don’t work as well as they should.

• Causes/problems that can lead to kidney failure:

  • Inadequate blood flow to the kidneys to filter.

  • Kidney damage from diseases such as:

  • Diabetes (high blood sugar).

  • High blood pressure.

  • Glomerulonephritis (damage to the kidney’s tiny filters).

  • Polycystic kidney disease.

  • Obstruction by kidney stones or scar tissue.

Symptoms of Kidney Problems

• Appetite loss.

• General ill feeling and fatigue.

• Headaches.

• Itching (pruritus) and dry skin.

• Nausea.

• Weight loss without trying.

Diagnosis and Tests

• Urinalysis may show protein or other urine changes; these may appear 6–10 months before symptoms.

• Tests that assess kidney function:

  • Creatinine clearance

  • Creatinine levels

  • Blood urea nitrogen (BUN)

  • Glomerular Filtration Rate (GFR)

  • GFR is a test used to check how well the kidneys are working; it estimates how much blood passes through the kidneys per unit time.

Additional Diagnostic Tests (to find cause or type of kidney disease)

• CT scan of the abdomen

• MRI of the abdomen

• Ultrasound of the abdomen

• Kidney biopsy

• Kidney scan

• Kidney ultrasound

Treatment and Lifestyle for Kidney Disease

• Blood pressure control slows damage: target blood pressure ≤ $130/80\text{ mm Hg}$.

• Common meds: ACE inhibitors (e.g., Enalapril, Captopril) or ARBs.

• Lifestyle changes to protect kidneys and reduce cardiovascular risk:

  • Do not smoke.

  • Eat meals low in fat and cholesterol.

  • Regular exercise (consult doctor/nurse before starting).

  • Consider cholesterol-lowering meds if needed.

  • Keep blood sugar under control.

  • Limit salt and potassium intake.

  • Always discuss OTC medications with a kidney specialist before use.

Stage of Kidney Failure (Overview)

• A kidney failure progression spectrum:

  • Acute kidney failure (ARF): a sudden loss of kidney function (can recover).

  • Chronic kidney disease (CKD): long, slow loss of kidney function.

  • End-stage renal disease (ESRD): kidneys have completely and permanently shut down.

• The stages are summarized by functional percentage ranges:

  • Stage 1: 90–100% function; usually no symptoms.

  • Stage 2: 60–89% function; often no symptoms; other health issues may be present (e.g., diabetes, high blood pressure, obesity).

  • Stage 3: 30–59% function; edema, protein in urine, fatigue, back pain, foamy/darker urine; microalbumin > $200\ \mu\text{g}$ (if mentioned); dietary restrictions may begin.

  • Stage 4: 15–29% function; Stage 3 symptoms plus nausea/vomiting.

  • Stage 5: 0–14% function; severe symptoms, fatigue, easy bruising/bleeding; anemia; thirst, cramps; very reduced urine; dialysis or transplant required.

Process of Renal Therapy (Renal Pharmacotherapy/Management Process)

• Identify drug that involves complex administration.

• Calculate the estimated Glomerular Filtration Rate (GFR).

• Identify potential risk for adverse drug effects.

• Assess need to simplify regimen.

• Assess patient’s adherence to drug therapy.

• Reconcile medications from patient’s available supply or medical records.

• Identify drug-related problems (DRPs), if any.

• Inform patient that medication may need long-term use; discuss with clinician to remedy DRPs.

• Promote patient adherence to the regimen.

• Follow-up outcome of remedial measures.

• Follow-up patient’s adherence to the regimen.

AKI: Acute Kidney Injury

• AKI is defined as the rapid loss of kidney function over a short period (less than 2 days) with:

  • An increase in serum creatinine (SCr) by at least $0.3\ \text{mg/dL}$ (≥ $26.5\ \mu\text{mol/L}$) within 48 hours, or

  • Urine output less than $0.5\ \text{mL/kg/h}$ for 6 hours.

AKI Classification and Etiology

• Categories:

  • Prerenal (decreased kidney perfusion)

  • Intrinsic (parenchymal or vascular disease)

  • Postrenal (urinary tract obstruction)

Prerenal, Intrinsic, and Postrenal Etiology (Key Examples)

• Prerenal: decreased intravascular volume (e.g., burns, pancreatitis, diarrhea); decreased cardiac output (myocardial dysfunction, hypertensive heart disease).

• Intrinsic: renal vascular disorders (vasculitis, malignant hypertension, scleroderma, HUS); glomerulonephritis (post-infectious, SLE, Wegener’s); interstitial nephritis (drug-induced: penicillins, cimetidine, PPIs, NSAIDs, hypercalcemia, phenytoin); tubular/ interstitial injury (ATN, crystal deposition, transplant rejection, protein deposition).

• Postrenal: urinary tract obstruction (ureteral/pelvic obstruction; extrarenal obstruction due to tumors, stones, clots); retroperitoneal or pelvic malignancy; prostate disease (e.g., BPH).

Drug-Related and Primary Etiologies for AKI (Examples)

• Primary etiologies involve drugs and toxins causing AKI:

  • Decreased kidney perfusion: diuretics, NSAIDs, ACE inhibitors.

  • Thrombotic microangiopathy (destruction of red blood cells): cyclosporin, tacrolimus, mitomycin C.

  • Tubular toxicity: aminoglycosides, amphotericin B, quinolones.

  • Cholesterol emboli: heparin, warfarin, streptokinase.

  • Glomerulopathy: captopril, NSAIDs, mercury, interferon-α.

  • Rhabdomyolysis: lovastatin, ethanol, diazepam.

  • Severe hemolysis: sulfonamides, quinidine, quinine.

  • Immune-mediated interstitial inflammation: penicillin, ampicillin, allopurinol, thiazide, NSAIDs, ciprofloxacin, cimetidine.

  • Intratubular obstruction (crystalluria/renal stones): ganciclovir, acyclovir, triamterene.

  • Ureteral obstruction (secondary to retroperitoneal fibrosis).

  • Ergotamine, pindolol, atenolol, methyldopa.

  • Drug-associated risk factors for AKI (overall).

Herbs to Avoid and Reported Risks

• Ginseng: hypertension risk.

• St John’s Wort: decreases blood levels of tacrolimus.

• Dandelion, alfalfa: may cause hyperkalemia.

• Star fruit: neurotoxic and nephrotoxic effects.

• Ginkgo biloba: risk of hemorrhagic complications.

Management of AKI (High-Risk Interventions)

• Discontinue all nephrotoxic agents when possible.

• Ensure volume status and perfusion pressure.

• Consider functional hemodynamic monitoring.

• Monitor serum creatinine and urine output.

• Avoid hyperglycemia.

• Consider alternatives to radiocontrast procedures.

• Non-invasive diagnostic workup first; consider invasive options as needed.

• Check for changes in drug dosing.

• Consider renal replacement therapy (RRT) if needed; consider ICU admission.

• Avoid subclavian catheters when possible.

Chronic Kidney Disease (CKD)

• CKD means kidney damage and impaired filtration of blood, leading to waste buildup and other health problems.

• Diabetes and high blood pressure are the most common causes.

• Kidney damage develops slowly over many years; many people have no symptoms until disease is advanced.

• Diagnosis often via blood and urine tests.

• Treatments cannot cure CKD but may slow progression and manage complications (blood pressure, blood sugar, cholesterol).

• CKD can still worsen over time.

End-Stage Renal Disease (ESRD)

• ESRD is the last stage of CKD where kidneys can no longer support day-to-day life.

• Usually follows CKD; progression over 10–20 years is common.

• ESRD requires renal replacement therapy (dialysis or transplant) to survive.

Treatment Options for ESRD

• Dialysis or kidney transplant.

• Diet restrictions or medications to support body function.

• Without dialysis or transplant, ESRD leads to death.

• Each patient’s outcome varies due to individual factors and treatment risks.

Dialysis Overview

• Dialysis removes toxins and excess fluid when kidneys fail.

• Hemodialysis (HD) and other dialysis types perform some kidney functions.

• A kidney transplant places a healthy kidney into the body to take over kidney function.

• Transplants may come from deceased or living donors; wait times can be long.

• After transplant, lifelong immunosuppressive drugs are required to prevent rejection.

Renal Replacement Therapy (RRT) Modalities

• Peritoneal dialysis (PD)

• Intermittent hemodialysis (IHD)

• Continuous renal replacement therapies (CRRT)

Function of the Kidney (Reinforced)

• Remove excess salt, water, and waste.

• Maintain safe levels of minerals and vitamins.

• Help regulate blood pressure.

• Aid in red blood cell production.

Haemofiltration (HF)

• A renal replacement therapy used in the ICU to treat AKI.

• Blood passes through a circuit to a semipermeable membrane where ultrafiltration removes waste and water by convection.

• Replacement fluid is added; blood is returned to the patient.

Haemodialysis (HD) Overview

• HD combines diffusion and convection using a high-flux dialyzer with an ultrafiltration coefficient.

• The combination aims to remove both large and small molecular weight solutes.

Special Considerations in Dialysis Patients

• Consider patient comprehension, dependency level, infections, GIT disturbances, dietary/fluid restrictions, cardiac status, liver function, pregnancy, age, etc.

Haemodialysis vs Peritoneal Dialysis (HD vs PD)

• HD: intermittent, typically 3x/week, in hospital or dialysis centers; requires trained personnel; fixed schedule; logistics and transport required; usually not done at home.

• PD: continuous or daily exchanges, done at home by patient or family; offers more travel flexibility; requires patient capability and a catheter; frequent daily exchanges.

• Infectious complications differ: HD often involves vascular access infections; PD involves peritoneal infections such as peritonitis.

• Cardiovascular risks differ: HD may cause rapid fluid shifts and hypotension; PD generally better preserves residual renal function and has less GI blood loss.

• Anemia management and psychosocial factors also differ between HD and PD.

Dialysis Circuit Diagrams (Conceptual)

• Haemodialysis circuit: blood from patient -> dialyzer -> waste removal -> returned to patient; anticoagulation may be used to prevent filter clotting.

• Peritoneal dialysis circuit: dialysate instilled into peritoneal space via catheter; waste is drawn out with drainage bags; equilibration occurs across peritoneal membrane.

CRRT vs IHD: Practical Comparison

• CRRT: continuous over 24 hours; low blood and dialysate flow rates; slow fluid and electrolyte removal; lower solute clearance per hour but over time

• IHD: typical 3–4 hour sessions, 3x weekly; higher flow rates; faster removal; greater hemodynamic stress; cheaper per session but requires setup in a unit

• CRRT advantages: stable hemodynamics, suitable for hemodynamically unstable patients; better for brain injury scenarios; reduced cerebral edema risk; supports diagnostic and therapeutic downtime

• IHD advantages: rapid clearance of small solutes; shorter overall treatment window; suitable for awake, stable patients

• Disadvantages: CRRT requires prolonged immobilization and is more expensive; IHD risk of hypotension and disequilibrium; CRRT may require continuous anticoagulation

Principles of Dialysis Transport

• Ultrafiltration (UF): movement of water across a semi-permeable membrane along a pressure gradient (high to low pressure) to remove fluid only.

• Convection: removal of small and large solutes using replacement fluid; solvent drag.

• Diffusion: removal of small solutes using dialysate; movement along concentration gradient until equilibrium is reached.

Anticoagulation in Renal Replacement Therapy (RRT)

• Purpose: prevent clotting of the filter and maintain membrane permeability; balance bleeding risk.

• Types and considerations:

  • Unfractionated heparin: widely available; short half-life; monitoring required; risk of bleeding and HIT (heparin-induced thrombocytopenia).

  • Low molecular weight heparin (LMWH): more predictable kinetics; often no routine monitoring; less HIT risk but more expensive; dose based on weight.

  • Citrate: regional anticoagulation; reduces bleeding risk; requires careful monitoring for citrate accumulation leading to metabolic acidosis and hypocalcemia in liver dysfunction or shock states.

Nutritional Considerations in Dialysis Patients

• Common reasons for inadequate nutritional intake in dialysis patients:

  • Loss of appetite.

  • Uremic toxin buildup.

  • Diet restrictions.

  • Dialysis-related catabolism.

  • Metabolic derangements and chronic inflammation.

  • Frailty, poverty, and advanced age, plus multiple comorbidities.

Kidney Transplant: Overview

• A kidney transplant places a healthy kidney into a patient with kidney failure.

• Donors may be deceased or living (often a family member).

• After transplant, lifelong immunosuppressive medications are required to prevent rejection.

• Transplant candidates are evaluated by a transplant center.

Transplant Care and Medications

• Perioperative and postoperative care includes:

  • Antihypertensives

  • Immunosuppressant therapy (e.g., cyclosporine, tacrolimus, mycophenolate mofetil, prednisolone, IV hydrocortisone)

  • Pain management, anesthesia considerations, fluid therapy, ESA (erythropoietin-stimulating agents)

  • DVT prevention and vaccinations as part of perioperative planning

Complications of ESRD

• Anemia

• Bleeding from stomach or intestines

• Bone, joint, and muscle pain

• Changes in blood glucose

• Nerve damage in legs/arms

• Fluid around the lungs (pulmonary edema)

• Hypertension, heart attack, and heart failure

• Hyperkalemia (high potassium)

• Increased infection risk

• Malnutrition

• Reproductive issues (miscarriage or infertility)

Diet for CKD/ESRD

• Diet may include:

  • Foods lower in protein

  • Adequate calories to prevent weight loss

  • Fluid restrictions

  • Limiting salt, potassium, phosphorous, and other electrolytes

Vaccinations for Dialysis Patients

• Higher infection risk due to compromised immunity; vaccines recommended:

  • Hepatitis A

  • Hepatitis B

  • Flu

  • Pneumococcal (PPV)

  • MMR

Prevention of Kidney Failure

• Protect kidneys by preventing or managing risk factors such as diabetes and hypertension.

• Maintain physical activity and healthy weight; get adequate sleep (7–8 hours).

• Stop smoking and limit alcohol.

• Stress management and overall health maintenance.

• Work with healthcare providers to manage diabetes, hypertension, and heart disease.

Closing: Key Takeaway Messages

• Early recognition and management of kidney disease can slow progression and reduce complications.

• AKI requires prompt assessment of hemodynamics, medications, and potential need for RRT.

• CKD and ESRD management involve a combination of pharmacologic therapy, lifestyle modification, diet, dialysis, and transplantation as appropriate.

• Multidisciplinary care (nephrology, nutrition, nursing, social work) is essential for optimal outcomes.