BPH Notes Flashcards
What is benign prostatic hyperplasia?
a nonmalignant enlargement of the prostate gland that occurs with aging.
What changes occur due to BPH?
- urethral obstruction
- detrusor overactivity (urge incontinence) and underactivity (overflow incontinence)
- 5 alpha reductase enzyme converts testosterone to dihydrotestosterone- a potent androgen that stimulates prostate growth.
- alpha adrenergic receptors are stimulated in the prostate and bladder neck which increases smoother muscle tone there contributing to urethral resistance.
What medication group help to address the stimulation of 5 alpha reductase enzyme with BPH and how do they work?
5 Alpha Reductase Inhibitors work by blocking the conversion of testosterone to dihydrotestosterone, reducing DHT levels, and consequently shrinking the prostate.
What medication group helps to address the stimulation of alpha-adrenergic receptors in a patient with BPH and how do they work?
Alpha blockers are medications that relax these smooth muscles in the prostate and bladder neck by blocking alpha adrenergic receptors, thereby decreasing urethral resistance and improving urine flow.
What are signs and symptoms of a patient with BPH?
- urinary obstruction
- postvoid dribbling
- sensation of incomplete emptying of bladder (overflow incontinence)
- increased urinary frequency during day and night (nocturia)
- urgency (urge incontinence)
What is the difference between selective and nonselective alpha blockers?
nonselective alpha blockers may be more suitable for patients who also require blood pressure management by blocking both alpha 1A and alpha 1B receptors. selective alpha blockers are more appropriate for patients who have history of hypotension and are sensitive to BP changes by only blocking alpha 1A receptors.
What enzymes are alpha blockers metabolized by?
CYP450 enzymes
Who is contraindicated for taking Silodosin (Rapaflo)?
Silodosin [Rapaflo] may be contraindicated in patients with severe chronic kidney disease (CKD).
what are adverse effects of alpha blockers?
drowsiness, nasal congestion, HA, orthostatic hypotension
What is an important note to consider when prescribing a patient Alfuzosin (Uroxatral)?
Alfuzosin [Uroxatral] may prolong the QT interval, requiring caution when use in patients who are taking other medications that can also prolong QT interval.
What is the MOA of adrenergic antagonists (alpha blockers)?
Block Alpha1A and/or Alpha1B adrenergic receptors in the prostate and bladder neck causing smooth muscle relaxation and decreased urinary obstruction.
What is the MOA of 5-Alpha Reductase Inhibitors?
Inhibit the enzyme 5-alpha reductase, which converts testosterone into dihydrotestosterone (DHT) reducing the size of the prostate over time which improves urine flow.
When is onset of action for adrenergic antagonists (alpha blockers)?
Quick onset, with symptomatic relief typically observed within 7-10 days.
What is the primary benefit of taking adrenergic antagonists (alpha blockers)?
Rapid improvement in urinary symptoms
What is the onset of action when taking 5-alpha reductase inhibitors?
Slow acting; takes 9-12 months to achieve maximum therapeutic effect.