This document provides information about the renal and urological systems and conditions that affect them. It describes the anatomy and functions of the kidneys, nephrons, bladder and urethra. Conditions discussed include chronic kidney disease, kidney stones, edema, urinary tract infections, and urinary incontinence. Drug treatments are outlined for these conditions, including diuretics, antibiotics, analgesics, and supplements. Non-drug therapies like dialysis and lifestyle changes are also mentioned.

1. Chapter 21
1

2. 2
Therapeutic Agents for the Renal System
1. Describe the major components of the renal and urological
systems.
2. List the primary symptoms of conditions associated with
dysfunction of both the renal and urological systems.
3. Recognize prescription and over-the-counter drugs used to
treat the conditions associated with the renal and
urological systems as discussed in this chapter.
4. Write the generic and trade names for the drugs discussed
in this chapter.
5. List appropriate auxiliary labels when filling prescriptions
for drugs discussed for the treatment of conditions
associated with the renal and urological systems.
Lesson 21.1

3. Anatomy and Physiology of the
Renal and Urological Systems
 Kidneys: Located inside upper abdominal cavity on
either side of vertebrae; bean shaped
 Renal fascia: Fibrous connective tissue that holds
kidneys stationary
 Renal artery: Where blood enters kidney
 Blood is filtered in the kidney
 Sodium and chloride reabsorbed into body and
circulatory system
 Renal vein and ureter leave kidney via hilus
 Renal vein returns blood to body after filtering process
3

4. Anatomy of the Urinary Tract and
Nephrons
4

5. Questions
 What is the function of the kidneys?
 What are nephrons and where can they be seen on the
previous diagram?
 What other organs excrete waste products from the
body?
5

6. Renal and Urological Systems
 Ureter carries waste removed from blood to bladder,
where it is stored for excretion
 Bladder is a holding tank that can expand
 Urine eliminated through urethra: Tube leading from
bladder to outside of body
 During urination, the sphincter muscles relax to open
the bladder while the bladder (which is also a muscle)
contracts to squeeze out the urine.
 Drugs are excreted through the renal system.
6

7. Kidney Structure
7
From McCance KL: Pathophysiology: the biologic basis for disease in adults and children, ed 6, St Louis, 2010, Mosby.

8. Function of the Kidneys
 Kidneys filter out and reabsorb nutrients and
chemicals
 Waste eliminated by excretion
 Four major functions of body:
 Absorption
 Distribution
 Metabolism
 Excretion
8

9. Function of the Kidneys (Cont.)
 Bladder holds up to 1000 mL of urine
 Body excretes about 960 mL/day
 Urine contains urea, produced by liver; form of
nitrogen that changes to ammonia
 Kidneys balance fluid content of body
 Fluids include water, blood, plasma, and ions
9

10. Function of the Kidneys (Cont.)
 Kidneys balance and eliminate ions within blood
 Acidosis and alkalosis: Imbalance of ions in blood
 Acidosis means too many free hydrogen ions
 Alkalosis means too many hydroxide ions
 Blood urea nitrogen (BUN) test determines levels of
acid in patient’s system
 Kidneys filter about 50 gallons of blood products daily
10

11. Nephron Function
 Nephrons do all work of regulation of fluids, solutes,
and wastes in kidney
 Each kidney contains millions of nephrons
 Nephrons work 24 hours/day
11

12. Nephron Anatomy
12

13. Tubular Reabsorption
 Two mechanisms affecting balance of ions: Ion
exchange and active transport
 Ion exchange: Sodium/hydrogen ion exchange (osmosis)
 Sodium helps to conduct nerve impulses, so it is important for
it to be reabsorbed into the circulatory system.
 Result: Decrease in excreted water
 Active transport: One-way uptake of sodium and
chloride from loop of Henle
 Result: Sodium returned to circulatory system
13

14. Tubular Secretion
 Tubular secretion takes place throughout the nephron
 First, ions, toxins, and water are secreted into collecting
duct
 Secretion and elimination of weak acids (aspirin and
penicillin) and weak bases (narcotic analgesics, metformin,
and antihistamines) takes place
 Second, secretion allows kidneys to regulate pH of body
through urine acidification
 Acidification: Process of eliminating extra hydrogen ions
through urine
 Urine pH 4 to 5; blood pH is 7.4
14

15. Tubular Secretion (Cont.)
 Hydrogen ions combine to form bicarbonate
 They are released into bloodstream to regulate overall
pH of body, maintaining homeostasis
 Bicarbonate molecules act as a buffer because they can
either bind hydrogen ions [creating a basic environment
by decreasing the hydrogen ion concentration] or
release hydrogen ions [creating an acidic environment
by increasing the hydrogen ion concentration]).
15

16. Importance of Electrolytes
 Kidneys maintain balance through electrolytes in the
body
 Specific cations and anions important
 Cations include calcium, potassium, magnesium, and
sodium
 Anions include chloride, bicarbonate, and phosphate
 Electrolytes are required for the body. They are
important on the cardiac cycle, the balance of water,
the formation of teeth, and the growth of cells, for
instance.
16

17. Conditions Affecting the Renal and
Urological Systems
 Many people can live with only one kidney or partial
kidney function
 Having less than 25% of normal kidney function causes
health problems. A patient with less than about 15% of
normal kidney function requires either dialysis or a
transplant for survival.
 Dialysis and/or kidney transplant is sometimes
necessary
 Other conditions include blockages, infections of
kidney, ureter, bladder, and urethra
17

18. Chronic Kidney Disease
 Progressive loss of renal function
 Causes: Diabetes mellitus and uncontrolled
hypertension, glomerulonephritis, pyelonephritis, and
vascular disorders
 Five stages based on glomerular filtration rate
 Early symptoms: Fatigue, headache, shortness of
breath, weight changes, and edema
 Dietary changes are important; protein restriction
18

19. Treatment of Chronic Kidney
Disease: Dialysis
 Waste products removed from blood
 Compensates for lack of filtration
 Two types: Hemodialysis and peritoneal dialysis
 Hemodialysis: Patient must visit clinic or hospital
 Peritoneal dialysis: Alternative to hemodialysis
 Nocturnal dialysis: Treatment received while sleeping
19

20. Negative aspects of dialysis
 Additional medications patients must take to further
balance pH and fluids
 The inconvenience of having to be stationary for a
length of time during a dialysis session
 Even sophisticated machinery cannot perform as
efficiently as the body’s own kidneys.
20

21. Drug Treatment for Chronic Kidney
Disease
 Nutrients lost during hemodialysis must be replaced
by supplements
 Vitamin supplements
 Antihypertensives
 Phosphorus-lowering medications
 Vitamin D supplements
 Kidneys are important in the synthesis of the active form of
vitamin D, which places people with CKD at risk of having
weak bones
21

22. Kidney Stones
 Kidney stones are small clumps of material that form
in the kidney from substances that pass through the
renal system
 Cystine
 Uric acid
 Struvite
 Calcium phosphate
 Calcium oxalate
 Kidney stones often do not cause any symptoms unless
they block the flow of urine.
22

23. Drug Treatment for Kidney Stones
 Calcium channel blockers and alpha blockers to help
speed up stone passing and reduce pain
 To prevent stones:
 Calcium: Thiazides and potassium citrate
 Uric acid: Allopurinol and potassium citrate
 Cystine: Captopril, tiopronin, and potassium citrate
23

24. Alternative Treatments
 Stones may pass on their own.
 For larger stones, lithotripsy, ureteroscopes, and/or
surgery may be necessary.
 The most commonly used surgical procedure for
kidney stone removal is extracorporeal shockwave
lithotripsy (ESWL). This procedure uses external
shock waves to break the stone into small particles,
which can be passed in the urine.
 Drink water and limit caffeine intake.
24

25. Edema
 Causes: Congestive heart failure (CHF), hypertension
 CHF: Heart muscle weakened by disease; decreases
efficiency; blood pumped less throughout body
 Signs and symptoms include edema, chest pain, fatigue,
dyspnea, and orthopnea
25

26. Edema (Cont.)
 Heart failure (HF): Kidneys retain fluid, puts more
work on heart, creating vicious cycle
 There is no cure for HF
 Hypertension can damage heart muscle/veins, leads to
HF
 Avoid salt and sitting for long periods of time
26

27. Drug Treatment for Edema
 Depends on underlying cause of the edema
 Main drugs are:
 Diuretic thiazides and thiazide-like agents
 Loop diuretics and potassium-sparing diuretics
 Carbonic anhydrase inhibitors
 Osmotics
 Two common beverage ingredients that are diuretics
 Caffeine and alcohol
27

28. Thiazides and Thiazide-like Agents
 Drug action: Increase urinary excretion of sodium and
chloride ions equally
 Inhibit normal process of reabsorption with ascending
tubule following loop of Henle and distal tubules
 Increased loss of potassium and bicarbonate
 Rapid onset of action
 Side effect is frequent urination
 Taken early in day to avoid nocturia
28

29. Loop Diuretics
 Loop diuretics inhibit reabsorption of sodium and
chloride in proximal convoluted tubule, distal
convoluted tubule, and loop of Henle
 Great deal of potassium is lost with urination
 They are taken early to avoid nocturia
29

30. Potassium-Sparing Agents
 These work primarily in distal convoluted tubule
 They inhibit sodium reabsorption and decrease
potassium loss in urine
 Large quantities of potassium-rich foods must be
avoided
 Bananas, orange juice, and potatoes
30

31. Osmotic Diuretics
 Osmotic diuretics inhibit tubular reabsorption of
water by increasing osmolarity of glomerular filtrate
 Used for prophylaxis of acute renal failure when
glomerular filtration is reduced
 Agents include: Urea, glycerin, and isosorbide (also
used for glaucoma)
31

32. Urinary Tract Infection
 Urinary tract infections (UTIs) are a common cause of
bacterial infections
 Most are caused by E. coli bacteria from the digestive
tract
 Women more susceptible because of a shorter urethra
 Catheterization is another cause
 Kidney infection: Glomerulonephritis and
pyelonephritis
 Bladder infection: Cystitis
32

33. Symptoms of Urinary Tract
Infections
 Symptoms of upper UTI:
 Lower back pain, stomach pain, nausea, vomiting, and
headache
 Symptoms of lower UTI:
 Frequent but small amounts of urine, dysuria, and
sometimes incontinence
33

34. Drug Treatment for Urinary Tract
Infections
 Bacterial infections: Cephalosporin and
fluoroquinolone
 Fungal infections: Fluconazole (Diflucan)
 Tetracycline for infections caused by some sexually
transmitted diseases (STDs)
34

35. Urinary Incontinence
 Common urinary condition
 Older adults, females, and women with multiple
pregnancies
 Stress continence: Coughing, sneezing; force placed on
bladder; urine released
 Urge incontinence has several causes: Decreased
bladder capacity, infection, and irritation
 Risk increased by alcohol and caffeine ingestion
 Common non-drug therapy treatment: Kegel exercises
(involve tightening of pelvic floor muscles)
35