Chapter 53: Male Sexal Dysfunction & Benign Prostatic Hyperplasia

Question 1

ED

Answer 1

Erectile dysfunction (ED), also known as impotence
Persistent inability to achieve or sustain an erection suitable for sexual intercourse

Affects up to 30 million men

Commonly associated with chronic illnesses

Risk for ED increases with advancing age

4% of men in 50s

17% of men in 60s

47% of men 75 years or older

Question 2

1st Lin x for ED

Answer 2

smoking cessation, exercise, looking for drugs that contrib

Question 3

Tx for ED

Answer 3

Drugs
Oral agents
Nonoral agents

Psychotherapy

Surgical implantation of penile prosthesis

Question 4

Oral agents for ED

Answer 4

Phosphodiesterase type 5 (PDE-5) inhibitors:
Sildenafil, vardenafil, and tadalafil

Originally CV drug

Question 5

PDE-5 inhibitors ADR

Answer 5

Hypotension (See 8.4 drop in SBP and 5.5 drop in DBP), priapism, headache, dyspepsia, flushing, nasal congestion, diarrhea, rash, dizziness, mild transient visual disturbances, intensification of obstructive sleep apnea

Rare side effects:
Nonarteritic ischemic optic neuropathy
Sudden hearing loss

Question 6

PDE-5 inhibitors drug interactions

Answer 6

Nitrates (could cause life-threatening hypotension)
Alpha blockers (can cause symptomatic postural hypotension)
Inhibitors of cytochrome P450 (CYP3A4) (can suppress metabolism)

Question 7

PDE-5 inhibitors precautions

Answer 7

Drug should be used with caution by men with the following conditions:
Myocardial infarction (MI), stroke, and life-threatening dysrhythmia within the past 6 months
Resting hypotension (BP below 90/50 mm Hg)
Resting hypertension (BP above 170/110 mm Hg)
Heart failure
Unstable angina

Should not be prescribed for men taking nitroglycerin or any other drug in the nitrate family

Question 8

Sildenafil (Viagra)

Answer 8

Only enhances normal erectile response in the presence of stimuli, No significant impact on men who do not have ED, Approved in 2005 as Revatio to treat pulmonary arterial hypertension

Available in 25-, 50-, and 100-mg tablets
Usual dose: 50 mg 1 hour before sexual activity

Question 9

PDE-5 inhibitors II

Answer 9

Relaxes arterial and trabecular smooth muscle in the penis
Vardenafil [Levitra], Tadalafil [Cialis], Avanafil [Stendra]

Question 10

Vardenafil [Levitra]

Answer 10

Prolongs QT interval; Dosing: 10 mg 60 minutes before intercourse; maximum dose 20 mg

Question 11

Tadalafil [Cialis]

Answer 11

Effects last up to 36 hours; Dosing: PRN: 5 to 20 mg no more than once per day; Daily: 2.5 to 5 mg daily (if activity anticipated twice weekly)

Question 12

Avanafil [Stendra]

Answer 12

Effects begin about 15 minutes after dosing and last about 2 hours; Dosing: 100 mg 30 minutes before intercourse

Question 13

Papaverine (smooth muscle relaxant) plus phentolamine (alpha-adrenergic blocking agent)

Answer 13

Increases arterial flow and decreases venous outflow in the penis

Administration and dosing: Injected directly into the corpus cavernosum
Desired effect achieved with as little as 0.1 mL.
Usual concentration: 30 mg/mL paperverine and 1 mg/mL phentolamine

Adverse effects: Priapism, painless fibrotic nodules in the corpus cavernosum, orthostatic hypotension

Question 14

Alprostadil (prostaglandin E1)

Answer 14

Increased arterial flow and decreased venous outflow in the penis

Administration and dosing:
Intracavernous: max 3 times per week; 5 to 40 mcg until erection achieved -Adverse effects: burning, priapism, penile fibrosis
Transurethral: Alprostadil pellets [Muse]; maximum twice in 24 hours; dosage determined in prescriber’s office; available in 125, 250, 500, and 1000 mcg

Question 15

BPH

Answer 15

Nonmalignant prostate enlargement
Caused by excessive growth of epithelial (glandular) cells and smooth muscle cells

Question 16

BPH s/sx

Answer 16

Urinary hesitancy, urgency, frequency
Dysuria
Nocturia
Straining to void
Postvoid dribbling
Decreased force and caliber of urinary stream
Sensation of incomplete bladder emptying

Question 17

BPH tx

Answer 17

Surgery

Watchful waiting

Drug therapy

5-Alpha-reductase inhibitors (mechanical obstruction)
Finasteride
Dutasteride

Alpha1-adrenergic antagonists (dynamic obstruction)

Question 18

5-Alpha-Reductase Inhibitors

Answer 18

Finasteride [Proscar]

Dutasteride [Avodart]

Question 19

Finasteride [Proscar]

Answer 19

Most effective in patients with a very large prostate (mechanical obstruction)

Adverse effects
Decreases ejaculate volume and libido
Gynecomastia
Decreases levels of prostate-specific antigen (PSA) 30-50%

If patient on proscar for 6mon and PSA is not declined, look for cancer

Question 20

Dutasteride [Avodart]

Answer 20

Similar to finasteride but with three differences:
Reduction in circulating dihydrotestosterone (DHT) is more complete
Harmful to a developing male fetus
Extremely long half-life (5 weeks)

Question 21

Alpha1-Adrenergic Antagonists

Answer 21

Approved for treatment of benign prostatic hyperplasia (BPH):
Terazosin [Hytrin]
Doxazosin [Cardura]
Tamsulosin [Flomax]
Alfuzosin [Uroxatral]
Silodosin [Rapaflo]

Blockade of alpha1 receptors relaxes smooth muscle in the bladder neck (trigone and sphincter)

Question 22

alpha 1 antagonists ADR

Answer 22

Tamsulosin [Flomax] and alfuzosin [Uroxatral]
Less likely to cause the effects of terazosin and doxazosin
Tamsulosin can cause abnormal ejaculation

Terazosin [Hytrin] and doxazosin [Cardura]
Hypotension, fainting, dizziness, somnolence, and nasal congestion

These drugs do not decrease PSA levels

Question 23

Alpha 1 antagonists drug interactions

Answer 23

Exercise caution with other medications that lower blood pressure
Organic nitrates, antihypertensive drugs, PDE-5 inhibitors used for ED
Inhibitors of CYP3A4

Cataract surgery: “Floppy-iris syndrome”

Question 24

Other drugs and supplements for BPH

Answer 24

Saw palmetto
Used widely
Effectiveness not supported

Tolterodine [Detrol]

Botulinum toxin
Diminish s/sx for 1 year

Question 25

A patient has been prescribed sildenafil [Viagra] for erectile dysfunction. Which instruction should the nurse include in the teaching plan?
A. Take the medication on an empty stomach.
B. Drink plenty of fluids to prevent priapism.
C. Avoid taking nitroglycerin with this drug.
D. Constipation is a common adverse effect.

Answer 25

Answer: C
Rationale: Taking nitrates with sildenafil may result in severe hypotension. Sildenafil can be taken with or without food. Patients who experience priapism (an erection lasting longer than 4 hours) should contact their health care provider immediately.

Question 26

A patient is taking finasteride [Proscar] for benign prostatic hyperplasia (BPH). The nurse should explain that this medication has what effect?
A. Decreases the size of the prostate gland
B. Relaxes smooth muscle of the prostate gland
C. Reduces the risk of prostate cancer
D. Improves sexual performance during intercourse

Answer 26

Answer: A
Rationale: Finasteride [Proscar] promotes the regression of prostate epithelial tissue and decreases the size of the mechanical obstruction.

Question 27

The nurse should instruct a patient prescribed sildenafil [Viagra] to avoid taking this medication with what?
A. Grapefruit juice
B. Milk
C. Crackers
D. Eggs

Answer 27

Answer: A
Rationale: Inhibitors of CYP3A4 (e.g., ketoconazole, itraconazole, erythromycin, cimetidine, saquinavir, ritonavir, and grapefruit juice) can suppress metabolism of sildenafil, thereby increasing its levels.