BPH Pharmacotherapy Exam 3 Flashcards
Physical Exam for BPH
- Digital rectal exam (DRE)
- Urine flow study
- Intravenous pyelogram (IVP)
- Cystoscopy
- Prostate specific antigen (PSA) blood test
- Urinalysis
Digital rectal exam (DRE)
- Usually the first test done to assess prostate
- Prostate is palpated through rectal wall
Urine flow study
- Reduced flow suggests BPH; best non-invasive study to detect lower urinary tract obstruction
- Normal is at least 10 mL/s
Intravenous pyelogram (IVP)
X-ray of the urinary tract that is used to identify obstructions or blockages
Cystoscopy
Allows for visualization of the prostate gland and a determination of the size and degree of obstruction
Prostate specific antigen (PSA) blood test
- To rule out prostate cancer
- Normal 0-4.0 ng/mL
Urinalysis
To determine if there is an underlying urinary tract infection or other problem such as stones causing obstructions
American Urologic Association/International Prostate Symptom Score
- 0-7 points: mild
- 8-19 points: moderate
- 20-35 points: severe
If a patient has mild BPH symptoms, what is the next step?
- Watchful Waiting
- Counsel on lifestyle measures
- Reassess in 6 or 12 month intervals
If a patient has moderate BPH symptoms, what is the next step?
- With ED: Alpha-1 blocker ± PDE5i
- Small Prostate and Low PSA: Alpha-1 blocker
- Large prostate (>30g) and increased PSA: Alpha-1 blocker + 5-alpha reductase inhibitor
- Predominant Irritative Voiding Symptoms: Alpha1 blocker + [Anticholinergic OR B3 agonist]
If a patient has severe BPH symptoms, what is the next step?
Surgery
What are the drug classes that can be used to treat BPH?
- Alpha-1 blocker
- 5-alpha reductase inhibitors
- PDE5i
- anticholinergics
- Beta-3 agonist
What are the Alpha-1 blocker drugs?
- Terazosin (Hytrin)
- Doxazosin (Cardura, XL)
- Alfuzosin (Uroxatral)
- Tamsulosin (Flomax) (3rd)
- Silodosin (Rapaflo) (3rd)
What are the 5-alpha reductase inhibitors drugs?
- Finasteride (Proscar)
- Dutasteride (Avodart)
What are the PDE5i drugs?
Tadalafil (Cialis®)
What are the anticholinergics drugs?
- Oxybutynin (Ditropan)
- Tolterodine (Detrol)
- Solifenacin (Vesicare)
- Trospium (Sanctura)
- Darifenacin (Enablex)
- Fesoterodine (Toviaz)
What are the Beta-3 agonist drugs?
Mirabegron (Myrbetriq)
Terazosin (Hytrin) pearls
- take at bedtime
- titrate 4-6 wks
- No renal or hepatic dosing
- food slows absorption
- NOT uroselective
Doxazosin (Cardura, XL) pearls
- QHS or QAM (doses are different); QH titrate wkly; QAM titrate 3-4 wks
- No renal dosing
- avoid in severe hepatic disease
- NOT uroselective
Alfuzosin (Uroxatral) pearls
- 100% uroselective
- after the same meal QD
- Avoid in severe renal disease
- C/I in severe hepatic disease
- food slows absorption
Tamsulosin (Flomax)
- 30 min after same meal QD; titrate 2-4 wks
- No renal or hepatic dosing
- food slows absorption
Silodosin (Rapaflo)
- once daily after meal
- renal dosing
- C/I in severe hepatic disease
- food slows absorption
MOA of Alpha-1 blocker
- Relax smooth muscles by blocking alpha1receptors in the bladder neck and prostate
Alpha-1 blocker monitoring
- Urine flow
- Blood pressure
- PSA (baseline and annually)
ADE of Alpha-1 blockers
- Orthostatic hypotension and dizziness; “first-dose” effect
- Lower volume of ejaculate
- Tachycardia
- Nasal congestion
Alpha-1 blockers contraindications
Floppy Iris Syndrome
Floppy Iris Syndrome
- Retinal detachment, lens problems or other complications
- Avoid in men with planned cataract surgery
- Avoid until the surgery is completed
Alpha-1 blocker drug interactions
- Potent CYP3A4 inhibitors (ketoconazole, clarithromycin, ritonavir) => [C/I for Alfuzosin, Silodosin, Tamsulosin, Caution for Doxazosin, okay for Prazosin and Terazosin]
- Alfuzosin increase risk for QT prolongation
- Tamsulosin (avoid in sulfa allergy)
- PDE5i (increase risk for hypotension; stabilize on alpha blocker before initiating)
Alpha-1 blocker clinical pearls
- All agents are equally effective and can lower AUA score by 30-40%
- Does not alter prostate size
- Generally takes 2-6 weeks before the benefits of these agents on BPH symptoms
- If therapy stopped, restart at initial dose
5-alpha reductase inhibitor dosing
- dosed iQD
- no renal dosing
- use w/ caution in severe hepatic disease
MOA of 5-alpha reductase inhibitors
- Inhibition of the 5-alpha reductase, which is an intracellular enzyme that converts testosterone into the principal intracellular androgen 5-alpha-dihydrotestosterone (DHT)
- This enzyme is located in cells of the prostate to facilitate increased levels of DHT which supports growth of prostate tissue
5-alpha reductase inhibitors monitoring
Obtain PSA @ Baseline, 3 months, then Annually
ADE of 5-alpha reductase inhibitors
- Erectile dysfunction
- Decreased volume of ejaculate
- Decreased libido
- Gynecomastia
5-alpha reductase inhibitor contraindications
Pregnant women or women who plan on becoming pregnant should not handle or be exposed to semen of men taking because of potential adverse effects on male fetuses if systemic absorption occurs
5-alpha reductase inhibitor clinical pearls
- Reduces prostatic androgen levels and can result in a decrease in prostate size by 25% as well as minimize the need for a future surgery
- Not recommended unless prostate ≥ 40gm and/or PSA >1.5 ng/mL
- Doses must be continued for 6-12 months to achieve the full benefits
Tadalafil (Cialis®) pearls
- may be considered as additional therapy to an alpha-1 blocker IF the patient also has ED and less severe BPH symptoms
- enhance smooth muscle relaxation in the prostate, bladder, and urethra
Combination Therapy of Alpha-1 Blocker with 5-Alpha-Reductase Inhibitor
- May be the best therapy for patients at greater risk for progression, such as men over 50 with low urine flow, high PSA levels, or large prostate glands (>30g)
- The alpha-1 blocker provides more rapid symptom relief and the 5-alpha-reductase inhibitor reduces prostate size and reduces progression
What are adjunct therapies for BPH?
- Anticholingerics
- Beta-3 agonist
Anticholingerics rationale for use
- help control irritative bladder symptoms
What should you do before initiating pt on anticholingerics?
confirm the patient’s postvoid residual volume < 150 mL (Normal is 0, > 25-50 mL implies failure of bladder emptying and predisposition to UTIs)
Anticholingerics pearls
- May take 1-2 weeks for effect
Oxybutynin (Ditropan) pearls
- 2-3x daily
- Use caution in renal disease
Tolterodine (Detrol) pearls
- BID
- Max with renal impairment is 1 mg
Solifenacin (Vesicare) pearls
- iQD
- Max with renal and hepatic disease and CYP3A4 is 5 mg
Trospium (Sanctura) pearls
- BID
- Use with caution in renal disease
Darifenacin (Enablex) pearls
- iQD
- no dosing / hepatic dosing
- Max with CYP3A4 drugs is 7.5 mg
Fesoterodine (Toviaz) pearls
- iQD
- Renal dosing
- max with CYP3A4 is 4 mg
MOA of Anticholingerics
Blocks muscarinic receptors in the detrusor muscle reducing contractions
Beta-3 agonist rationale for use
help control irritative bladder symptoms
MOA of Beta-3 agonist
- relaxing the detrusor muscle to increase the bladder’s storage capacity and prolong the interval between voidings
- 95% of receptors in urinary bladder are B3
Beta-3 agonist pearls
May take 2-8 weeks to see effect
surgery option for BPH
- Transurethral Resection of the Prostate
(TURP) - Prostatectomy
surgery option for BPH: complications
- Retrograde ejaculation
- Erectile dysfunction
- Urinary Incontinence
Transurethral Resection of the Prostate
TURP
- Improves urinary flow rate 125%
- Improves AUA score by 10-18 points
- Improves voiding symptoms by 90%
What are complimentary and alternative medicine used for BPH?
- Saw palmetto
- Beta-sitosterol
- Pygeum (from bark of P. africanum)
- lack of data bout effectiveness
