Pharmacology for Nurses Unit 35 Review: Drugs for Urinary & Bladder Disorders

Key Concepts

• Urinary and bladder disorders affect the lower urinary tract, which includes the bladder, urethra, and prostate gland in males
• Common symptoms of urinary and bladder disorders include urinary frequency, urgency, incontinence, and difficulty voiding
• Urinary tract infections (UTIs) are caused by bacterial invasion of the urinary tract, most commonly by Escherichia coli (E. coli)
• Overactive bladder (OAB) is characterized by sudden, strong urges to urinate and frequent urination, often leading to incontinence
• Benign prostatic hyperplasia (BPH) is a non-cancerous enlargement of the prostate gland that can cause urinary symptoms in older men
• Pharmacological interventions for urinary and bladder disorders aim to relieve symptoms, treat infections, and improve quality of life
• Nurses play a crucial role in assessing patients, administering medications, monitoring for side effects, and providing patient education

Types of Urinary & Bladder Disorders

• Urinary tract infections (UTIs) can affect the lower urinary tract (cystitis) or the upper urinary tract (pyelonephritis)
  • Risk factors for UTIs include female anatomy, sexual activity, and urinary catheterization
• Overactive bladder (OAB) is a chronic condition that causes sudden urges to urinate and frequent urination
  • OAB can be idiopathic or secondary to neurological disorders, such as multiple sclerosis or Parkinson's disease
• Stress urinary incontinence (SUI) occurs when physical activity or increased abdominal pressure causes involuntary urine leakage
• Urge urinary incontinence (UUI) is associated with a sudden, intense urge to urinate followed by involuntary urine leakage
• Benign prostatic hyperplasia (BPH) is a common condition in older men that can cause urinary symptoms due to prostate enlargement
• Interstitial cystitis (IC) is a chronic bladder condition characterized by pelvic pain, urinary frequency, and urgency
• Neurogenic bladder is a dysfunction of the bladder due to neurological disorders or spinal cord injuries

Pharmacological Interventions

• Antibiotics are used to treat bacterial urinary tract infections (UTIs)
  • Commonly prescribed antibiotics for UTIs include trimethoprim-sulfamethoxazole (Bactrim), nitrofurantoin (Macrobid), and ciprofloxacin (Cipro)
• Anticholinergic medications, such as oxybutynin (Ditropan) and tolterodine (Detrol), are used to treat overactive bladder (OAB) by relaxing the bladder muscle
• Beta-3 adrenergic agonists, such as mirabegron (Myrbetriq), are an alternative to anticholinergics for OAB treatment
• Alpha-1 adrenergic antagonists, such as tamsulosin (Flomax) and alfuzosin (Uroxatral), are used to treat benign prostatic hyperplasia (BPH) by relaxing the prostate and bladder neck
• 5-alpha reductase inhibitors, such as finasteride (Proscar) and dutasteride (Avodart), are used to treat BPH by reducing the size of the prostate gland
• Pentosan polysulfate sodium (Elmiron) is an oral medication used to treat interstitial cystitis (IC) by restoring the protective bladder lining
• Intravesical therapies, such as dimethyl sulfoxide (DMSO) and hyaluronic acid, are instilled directly into the bladder to treat IC

Mechanism of Action

• Antibiotics work by inhibiting bacterial cell wall synthesis, protein synthesis, or DNA replication, depending on the specific class of antibiotic
• Anticholinergic medications for OAB block the action of acetylcholine on muscarinic receptors in the bladder, reducing involuntary bladder contractions
• Beta-3 adrenergic agonists for OAB stimulate beta-3 receptors in the bladder, leading to relaxation of the detrusor muscle and increased bladder capacity
• Alpha-1 adrenergic antagonists for BPH block the action of norepinephrine on alpha-1 receptors in the prostate and bladder neck, reducing smooth muscle tone and improving urine flow
• 5-alpha reductase inhibitors for BPH block the conversion of testosterone to dihydrotestosterone (DHT), which is responsible for prostate growth
• Pentosan polysulfate sodium for IC is thought to restore the glycosaminoglycan (GAG) layer of the bladder, reducing inflammation and protecting the bladder wall
• Intravesical therapies for IC work by directly delivering medications to the bladder, reducing inflammation and promoting healing of the bladder lining

Drug Administration and Dosing

• Oral antibiotics for UTIs are typically taken for 3-7 days, depending on the specific antibiotic and the severity of the infection
  • Dosing varies by antibiotic; for example, trimethoprim-sulfamethoxazole (Bactrim) is usually taken twice daily, while nitrofurantoin (Macrobid) is taken four times daily
• Anticholinergic medications for OAB are usually taken orally once or twice daily, with dosing adjusted based on patient response and tolerability
• Mirabegron (Myrbetriq) for OAB is taken orally once daily, with a recommended starting dose of 25 mg and a maximum dose of 50 mg
• Alpha-1 adrenergic antagonists for BPH are typically taken orally once daily, with dosing varying by specific medication
  • Tamsulosin (Flomax) is usually started at 0.4 mg daily, while alfuzosin (Uroxatral) is started at 10 mg daily
• 5-alpha reductase inhibitors for BPH are taken orally once daily, with finasteride (Proscar) dosed at 5 mg and dutasteride (Avodart) dosed at 0.5 mg
• Pentosan polysulfate sodium (Elmiron) for IC is taken orally three times daily, with a recommended dose of 100 mg per capsule
• Intravesical therapies for IC are typically administered weekly for 6-8 weeks, then as needed for maintenance, with dosing varying by specific medication

Side Effects and Adverse Reactions

• Antibiotics for UTIs can cause gastrointestinal side effects, such as nausea, vomiting, and diarrhea
  • Some antibiotics, such as ciprofloxacin (Cipro), may cause more serious adverse reactions, including tendon rupture and QT prolongation
• Anticholinergic medications for OAB can cause dry mouth, constipation, blurred vision, and drowsiness
  • In older adults, anticholinergics may cause cognitive impairment and increase the risk of falls
• Mirabegron (Myrbetriq) for OAB can cause hypertension, nasopharyngitis, and urinary tract infections
• Alpha-1 adrenergic antagonists for BPH can cause orthostatic hypotension, dizziness, and ejaculatory dysfunction
• 5-alpha reductase inhibitors for BPH can cause decreased libido, erectile dysfunction, and gynecomastia
• Pentosan polysulfate sodium (Elmiron) for IC can cause gastrointestinal side effects, headache, and hair loss
  • Rare but serious adverse reactions include thrombocytopenia and liver function abnormalities
• Intravesical therapies for IC can cause bladder discomfort, urinary frequency, and hematuria

Nursing Considerations

• Assess patients for signs and symptoms of urinary and bladder disorders, including urinary frequency, urgency, incontinence, and pain
• Review patient medication history and allergies before administering medications for urinary and bladder disorders
• Monitor patients for side effects and adverse reactions to medications, and report any significant findings to the healthcare provider
• Ensure proper storage and handling of medications, especially for intravesical therapies that require sterile technique
• Encourage patients to maintain adequate hydration and to avoid bladder irritants, such as caffeine and alcohol
• Provide emotional support and resources for patients with chronic urinary and bladder disorders, as these conditions can significantly impact quality of life
• Collaborate with other healthcare professionals, such as urologists and pelvic floor physical therapists, to provide comprehensive care for patients with urinary and bladder disorders

Patient Education and Monitoring

• Teach patients about the proper use, storage, and disposal of medications for urinary and bladder disorders
• Educate patients on the importance of completing the full course of antibiotics for UTIs, even if symptoms improve
• Instruct patients taking anticholinergic medications for OAB to rise slowly from a seated or lying position to avoid dizziness or falls
• Advise patients taking alpha-1 adrenergic antagonists for BPH to be cautious when driving or operating machinery, as these medications can cause dizziness
• Encourage patients with OAB or IC to perform pelvic floor muscle exercises (Kegels) to improve bladder control and reduce symptoms
• Teach patients with IC about bladder irritants and the importance of maintaining a bladder-friendly diet
• Instruct patients on proper hygiene techniques to prevent UTIs, such as wiping from front to back and avoiding the use of harsh soaps or douches
• Emphasize the importance of regular follow-up appointments to monitor treatment effectiveness and adjust medications as needed