Renal and Urinary System Medications

what structures make up the organs of the urinary system?

1. ureters

2. bladder

3. urethra

4. kidneys

what is glomerular filtration?

the first step of urine formation, where blood is filtered through three layers of the glomerular membrane to remove waste and form filtrate

what are the three layers of the glomerular filtration membrane?

1. endothelium of the glomerular capillaries

2. basement membrane

3. podcyte (epithelial) layer with filtration slits

what happesns to the bladder when it is empty?

it collapses and lies flat

what is the function of the detrusor muscle?

contracts to expel urine during urination

what do the ligaments surrounding the bladder do?

provide support and help maintain normal position in the pelvis

what is the function of the urethra

to transport urine from the base of the bladder to the outside of the body.

what tissues line the urethra?

smooth muscle and connective tissue.

how long is the female urethra?

3-4 cm

what important structure is the female urethra connected to?

the anterior vaginal wall

how long is the male urethra?

about 20 cm

how many sections does the male urethra have?

four sections; the prostate is considered to be one of those section

what type of medication is mannitol?

osmotic diuretics

what are the MOA, indications, drug interactions, food interactions, and adverse effects of mannitol?

1. MOA: decreases sodium and water reabsorption in the proximal tubule and loop of Henle, which increases the osmotic pressure, leading to increased urine output

2. indications: used to treat increased intracranial pressure (ICP) and intraocular pressure (IOP)

3. drug interactions: acetomiophen, aspirin, and use cautiously with nephrotocix drugs

4. food interactions: alcohol, black licorice

5. adverse effects: hypokalemia, hyponatremia, hypotension, hypovolemia, azotemi, oliguria, heart failure, lung congestion, peripheral edema

can mannitol be used for heart failure? What is it primarily used for?

• No — mannitol is not used for heart failure because it increases intravascular volume and can worsen HF or cause pulmonary edema.

• Primary Uses: Treats increased intracranial pressure (ICP) and increased intraocular pressure (IOP). Also sometimes used for renal protection in specific situations.

why does mannitol increase intravascular volume?

mannitol stays in the bloodstream and increases plasma osmolarity, pulling water from tissues into the blood and temporarily increasing intravascular volume.

if mannitol increases intravascular volume, how does it lower ICP?

mannitol creates an osmotic gradient that draws water out of swollen brain tissue into the bloodstream, reducing brain volume and lowering intracranial pressure.

Because ICP (mechanical pressure) and osmotic pressure are completely different.

• The swollen brain has high physical pressure but low osmolarity (too much water, fewer solutes).

• Mannitol stays in the blood and makes the blood highly osmolar (high solute concentration).

• Water always moves toward higher osmolarity, not higher physical pressure.
  ➡ So water leaves the swollen brain → enters the mannitol-rich blood → brain volume decreases → ICP drops.

which sign is most concerning for the patient receiving mannitrol?

1. lung congestion and peripheral edema

2. increased urine output

3. orthostatic hypotension

4. elevated blood glucose levels

lung congestion and peripheral edema

the nurse should monitor the patient receiving spironolactone for which adverse effect?

1. nausea and vomiting

2. increased intracranial pressure

3. hearing loss

4. cardiac arrhythmias
   

cardiac arrhythmias

• spironolactone is a potassium-sparing diuretic, so it can cause hyperkalemia. Elevated potassium levels can lead to dangerous cardiac arrhythmias, which is the most serious adverse effect the nurse should monitor for.

which medication could be prescribed to treat hyperkalemia?

1. mannitol

2. hydrochlorothiazide

3. Spironolactone

4. Furosemide

Furosemide

Furosemide is a loop diuretic that increases potassium excretion, making it useful for treating hyperkalemia (loop diuretic is most potent)

• Mannitol → osmotic diuretic; does not correct potassium

• Hydrochlorothiazide → thiazide diuretic; causes mild K⁺ loss but not used to treat hyperkalemia

• Spironolactone → potassium-sparing; can worsen hyperkalemia

The nurse is providing discharge teaching for a patient who was started on a thiazide diuretic during this hospitalization. Which statement indicates that additional instruction is required?

1. “I’m concerned about getting up to go to the bathroom all night every night.”

2. “I will let the doctor know if I develop leg cramps.”

3. “I need to read food labels to check for salt.”

4. “I need to eat some potassium every day for a month or so.”

1. “I’m concerned about getting up to go to the bathroom all night every night.”

what are urinary anti-infectives used to treat?

UTIs (main use), plus pyelonephritis, cystitis, prostanitis, and urethritis

is UTI incident higher in male or female?

females - they are 10x higher in female than male because of the shorter urethra which allow for bacteria to enter more easily

what type of bacteria most often causes UTIs?

gram-negative bacterai from the GI tract (especially E. Coli)

what is the MOA, indications, drug interaction, food interactions, and adverse effects of nitrofurantoin?

1. MOA: interference with enzymes of bacteria to prevent growth

2. indications: treatment of urinary tract infections (UTIs)

3. drug interactionsL spironolactone, antacids

4. food interactions: none

5. adverse effects: hypersensitivity, peripheral neuropathies, hepatitis, vertigo , headche

what is the nursing implication for nitrofurantoin?

1. administer with food or milk

2. urine discoloration

3. encourage fluid intake

4. rinse mouth after taking

5. contraindicated during the third trimester or if breastfeeding

when is urinary anti-infection contraindicated?

during the 3rd trimester and while breastfeeding

what is the MOA, indications, drug interaction, food interaction, and adverse effects of trimethoprim and sulfamethoxazole (TMP/SMX)?

1. MOA: inhibits the bacterial synthesis of tetrahydrofolic acid, which is essential for the synthesis of bacterial DNA

2. indications: treatment of UTI

3. drug interactions: contraindicated in patient with sulfa allergies, dofetilide, warfarin, NSAIDs, and digoxin

4. food interaction: none

5. adverse effects: N, v, rash, itching, hyperkalemia, hepatic necrosis, photosensitivity

what is the nursing implication for trimethoprim and sulfamethxaazole?

1. sun safety education

2. monitor I/Os

3. USG

what is the MOA, indications, drug interactions, and adverse effects of phenazopyridine hydrochloride (Pyridium)?

1. MOA: produces a local anesthetic effects on the mucosa of the ureters and bladder

2. indications: UTI symptoms (e.g., burning/pain/urgency), bladder spasm

3. drug interactions: lidocaine, procaine, tetracaine

4. adverse effects: jaundice, rash, anemia, renal and hepatic toxicity

what is the nursing implication for phenazopyridine hydrochloride?

1. bodily fluid will turn reddish-orange

2. cannot take for more than 2 days

what are the 3 main drug classes for urinary problems? and how do they work?

1. antispasmodics

2. antimuscarinic (a type of anticholinergic)

3. anticholinergics (relaxes the bladder muscle for OAB which is why it causes urinary retention)

they relax the muscles in the bladder

how is overactive bladder defined?

“Urgency, with or without urge incontinence, usually with frequency and nocturia.”

what is overative bladder though to be caused by?

an overactive detrusor muscle in the bladder

what are the key symptoms of overactive bladder?

frequency, urgency, urinary incontinence

what type of drugs are used as urinary antispasmodics for OAB?

anticholinergic agents (also called urinary antispasmodics)

how do anticholinergic agents work for OAB?

They block cholinergic receptors in the bladder’s detrusor muscle → reduce bladder spasms → decrease urgency, frequency, and incontinence.

what are the classic antichlonergic side effects?

1. dry mouth

2. constipation

3. blurred vision

4. urinary retention

5. tachycardia

6. dry eyes

7. confusion

can’t see, can’t pee, can’t spit, can’t shit

what is the common suffix for antihcholinergic medications used for OAB?

1. -terodine

2. -fenacine

3. except for oxybutynin which doesnt follow the rule

common examples:

• Fesoterodine

• Oxybutynin

• Solifenacin

• Tolterodine

• Darifenacin

what is the MOA, indications, drugs interactions, food interactions, and adverse effects of oxybutynin?

1. MOA: direct antispasmodic effect and inhibits acetylcholine action on smooth muscle

2. indication: overactive bladder syndrome

3. drug interaction: anticholinergics and antibiotics

4. food interactions: none

5. adverse effects: insomnia, dizziness, HA, antichlonergic effects, and angioedema

what is the nursing implications for oxybutynin?

1. take on an empty stomach

2. increase dietary fibers

what does a urinary stimulant do?

stimulates the smooth muscle of the bladder → increases bladder contractions → improves bladder emptying

when are urinary stimulants used?

for urinary retention (not OAB)

what is the main urinary stimulant drug?

bethanechol chloride (Duvoid)

bethanechol acts like what type of drug?

cholinergic (parasympathomimetic) - it “turn on” the bladder

what is the MOA, indications, contraindications, and adverse effects of bethanechol chloride (Duvoid)?

1. MOA: cholinergic urinary stimulant that stimulates the parasympathetic NS to increase the tone and contractions of the bladder

2. indicationsL post-op and pospartum urinary retention, neurogenic bladder

3. contraindications: hyperthyroidism, CAD, seizures, Parkinson’s disease, bradycardia, hypotension

4. adverse effects: headache, urgency, sweating, increased risk of UTI

what is the nursing implication for bethanechol chloride?

take on an empty stomach

(REVIEW) why is bethanechol contraindicated in these conditions: hyperthyroidism, CAD, seizures, Parkinson’s disease, bradycardia, hypotension?

Because bethanechol is cholinergic (↑ parasympathetic activity), it can:

• Hyperthyroidism: trigger cardiac instability

• CAD: ↓ HR/BP → ↓ coronary perfusion

• Seizures: lower seizure threshold

• Parkinson’s: ↑ ACh → worsens symptoms

• Bradycardia: slow HR even more

• Hypotension: drop BP further

where is the prostate located and what does it surround?

at the base of the bladder, surrounding part of the urethra.

what happens to the prostate as men age?

It can enlarge, leading to benign prostatic hyperplasia (BPH).

what causes obstructive symptoms in BPH?

Narrowing of the bladder neck and urethra.
Examples: weak stream, hesitancy, dribbling.

what causes irritative symptoms in BPH?

Incomplete emptying and possible UTIs due to obstruction.
Examples: frequency, urgency, nocturia.

how do alpha-adrenergic blockers help in BPH?

They block alpha receptors on the prostate, causing muscle relaxation → improves urine outflow.

do alpha-adrenergic blockers shrink the prostate?

NO! they relax the muscle but do not reduce prostate size

how should alpha-adrenergic blockers be taken?

once daily - with the same meal each day

what is the common suffix for alpha-adrenergic blockers?

most ends in -zosin or -osin

1. alfuzosin

2. doxazosin

3. silodosin

4. tamsulosin

5. terazosin

what is MOA, indications, drug interactions, food interactions, and adversr effects of Tamulosin (Flomax)?

1. MOA: relaxes the smooth muscle in the bladder and prostate

2. indications: benign prostate hyperplasia management

3. drug interactions: PDE5 inhibitors

4. food interactions: grapefruit juice

5. adverse effects: dizziness, vertigo, retrograde ejaculation, postural hypotension, priapism

how do 5-alpha reductase inhibitors work?

they block conversion of testosterone → dihydrotestosterone (DHT) → they shrink the prostate gland →

true or false: 5-alpha reductase inhibitors can take weeks to work (a very slow onset)

true

what are the common suffix for 5-alpha reductase inhibitors?

-teride

1. dutasteride

2. finasteride

what is the MOA, indications. drug interactions. and adverse effects of finasteride?

1. MOA: shrink size of prostate gland

2. indications: BPH, male pattern baldness

3. drug interactions: drugs that cvause hypotension

4. adverse effects: hypotension, dizziness, increase in prostate CA, gynecomastia, ED, decrease in libido and orgasms, male infertility, ejaculation disorders

what is the nursing implication for fenesteride?

gloves when handling, monitor BP and med history

what is erectile dysfunction?

consistent inability to achieve or maintain an erection sufficient for satisfactory sexual activity.

does ED increase with age?

yes, prevalence increases, but it is not an inevitable part of aging

what factors contribute to ED?

a cmobination of vascular, neurologic, and psychological factors

what vascular/psychological/physical conditions increase ED risk?

1. HLP

2. HTN

3. DM

4. CAD

5. PVD

6. tobacco use

7. stress

8. depression

9. interpersonal relationship issues

10. trauma

11. TURP

12. prostatectomy

13. gender-affirming surgery

14. diabetes

15. alcohol abuse

W=what conditions do PDE5 inhibitors treat?

Erectile dysfunction, pulmonary hypertension, and benign prostatic hyperplasia (BPH).

how do PDE5 inhibitors work?

They block the PDE-5 enzyme, preventing breakdown of a molecule that relaxes smooth muscle → increases blood flow to the penis and lungs.

what is the common suffix for PDE5 inhibitors?

-afil

1. tadalafil

2. sildenafil (Viagra)

3. avanafil

A 65-year-old male patient presents to the urology clinic with lower urinary tract symptoms including frequency and hesitancy. After a thorough assessment, the patient is diagnosed with benign prostatic hyperplasia (BPH) and is prescribed tadalafil. The patient is concerned about the effectiveness of tadalafil for BPH. What information should the nurse include in their response to address the patient’s concerns?

1. Tadalafil primarily treats BPH by reducing prostate size.

2. Tadalafil is not effective for treating BPH and is primarily used for erectile dysfunction.

3. Tadalafil can help improve BPH symptoms by relaxing the muscles in the prostate and bladder neck.

4. Tadalafil is the first-line treatment for BPH and is recommended for all patients with this condition.

1. Tadalafil can help improve BPH symptoms by relaxing the muscles in the prostate and bladder neck

Why this is correct

• Tadalafil (a PDE-5 inhibitor) improves BPH symptoms by relaxing smooth muscle in the prostate and bladder neck, improving urine flow.

• It does NOT shrink the prostate (only 5-alpha reductase inhibitors do that).

• It is effective for BPH, but it is not first-line for all patients.

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Why the other answers are wrong

• “Reduces prostate size” → FALSE. PDE-5 inhibitors don’t shrink the prostate.

• “Not effective for BPH” → FALSE. Tadalafil is FDA-approved for BPH.

• “First-line for all patients” → FALSE. Alpha blockers are usually first-line.

A nurse is caring for a patient with an overactive bladder who is prescribed oxybutynin. Which adverse effect will the nurse include when educating the patient about this medication?

1. Diarrhea

2. Urinary urgency

3. Dry mouth

4. Restlessness
   

1. Dry mouth

Why?

Oxybutynin is an anticholinergic used for overactive bladder.
Anticholinergic medications commonly cause:

• Dry mouth ✔

• Constipation

• Blurred vision

• Urinary retention

• Dry eyes

• Drowsiness/confusion (esp. older adults)

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Why the others are wrong

• Diarrhea → Anticholinergics cause constipation, not diarrhea.

• Urinary urgency → Oxybutynin reduces urgency.

• Restlessness → Not a typical effect; sedation or confusion is more common.

A nurse is caring for a patient with urinary tract discomfort. The health care provider prescribes phenazopyridine hydrochloride. The nurse instructs the patient that this drug is classified as an:

1. Antispasmodic drug

2. Analgesic drug

3. Anti-infective drug

4. Anticholinergic drug

1. analgesic drug

The nurse is providing discharge teaching for a patient who has a new prescription for tadalafil. The nurse will caution the patient about which of the following side effects?

1. Angioedema

2. Urinary urgency

3. Hemolytic anemia

4. Vasomotor response

✅ Vasomotor response

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Why:

• Tadalafil is a PDE5 inhibitor that relaxes smooth muscle and increases blood flow.

• Common side effects are vasomotor-related:

  • Flushing

  • Headache

  • Dizziness

  • Hypotension

---

Why the others are incorrect:

• Angioedema → Not a common side effect of tadalafil.

• Urinary urgency → PDE5 inhibitors don’t typically cause this; they may actually help with BPH symptoms.

• Hemolytic anemia → Not associated with tadalafil.

Which of the following is the potential effect of trimethoprim and sulfamethoxazole on potassium levels in a patient?

1. Hyperkalemia

2. Hypokalemia

3. No effect on potassium levels

4. Variable effect on potassium levels
   

1. ✅ Hyperkalemia

   ---

   Why:

   • Trimethoprim (part of TMP-SMX) can block potassium excretion in the distal tubules of the kidney.

   • This can lead to elevated potassium levels (hyperkalemia), especially in:

     • Older adults

     • Patients with kidney disease

     • Patients taking other potassium-sparing drugs

   ---

   Why the others are incorrect:

   • Hypokalemia → Opposite effect; TMP-SMX does not lower potassium.

   • No effect → Incorrect; potassium can be affected.

   • Variable effect → Usually predictable as hyperkalemia.

A nurse is providing discharge instructions to a patient who has been prescribed, concomitantly with fosfomycin, phenazopyridine hydrochloride for symptomatic relief of urinary pain and discomfort. Which statement by the patient indicates a need for further education regarding the use of phenazopyridine hydrochloride?

1. “I should expect my urine to turn orange or reddish in color.”

2. “I will take this medication with meals to minimize stomach upset.”

3. “I understand that this medication may stain my contact lenses.”

4. “I will continue taking this medication until my symptoms completely resolve.”

✅ “I will continue taking this medication until my symptoms completely resolve.”

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Why:

• Phenazopyridine hydrochloride is a urinary analgesic, not an antibiotic.

• It relieves symptoms (burning, urgency, pain) but does not treat the infection.

• Patients should follow the prescribed course of the antibiotic (e.g., fosfomycin) even if symptoms improve. Continuing phenazopyridine beyond the recommended duration is unnecessary and may increase side effects.

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Why the other statements are correct:

• Urine discoloration (orange/red) → expected side effect.

• Take with meals → helps minimize stomach upset.

• May stain contact lenses → true; patients should be cautioned.