BPH Flashcards
What are some medications that can aggravate the s/sx of BPH?
- Anticholinergics
- α1-adrenergic agonist
- Opioid analgesics
- Diuretics
- Testosterone
What medications can be used to treat BPH? (4) (FAAP)
- α-adrenergic antagonist (selective, non-selective)
- 5α-reductase inhibitors (5ARIs)
- Phosphodiesterase 5 inhibitor (PDE-5)
- Anti-muscarinics
MOA of α-adrenergic antagonists in Tx of BPH?
Antagonise α-1 adrenergic receptors → relax prostate SM → improve urine flow and s/sx
Name the types of non-selective α-adrenergic antagonist (2)
What do they act on (ie why are they non-selective?)
Doxazosin, Terazosin
They antagonise both peripheral vascular and urinary α-1 adrenergic receptors
ADEs of NON-SELECTIVE α-adrenergic antagonists?
How do we deal with this?
Risk of hypotension and syncope
Start low, titrate slowly to therapeutic dose
Name the types of selective α-adrenergic antagonists (3)
What do they act on (ie why are they selective?)
Alfuzosin, Tamsulosin, Silodosin
They selectively antagonise α-1 adrenergic receptors in prostate and LUT
Benefits that selective α-adrenergic antagonists have over non-selective α-adrenergic antagonists?
Lesser risk of hypotension → no need dose titration
What are α-adrenergic antagonists used for (1) and NOT used for (3)?
Moderate-severe LUTS with small prostate (< 40g)
- Do not reduce prostate size
- Do not prevent progression of BPH/ need for surgery
- No effect on PSA
General SEs of α-adrenergic antagonists?
Muscle weakness, fatigue, ejaculatory disturbance, headache
ADEs of non-selective α-adrenergic antagonists?
What type of pts should we avoid this in?
Dizziness, first dose syncope, orthostatic hypotension
- Avoid in pts with Hx of syncope
- Avoid is monoTx in pts with BPH and HTN
ADEs of selective α-adrenergic antagonists?
Especially Tamsulosin?
What type of pts should we avoid this in?
Ejaculatory disturbance (S > T > A)
Tamsulosin: Intraoperative Floppy Iris Syndrome (IFIS)
- Avoid initiation in men with planned cataract surgery until surgery is completed (or hold ≥14d before surgery)
Onset of α-adrenergic antagonists?
Fast → days-weeks
Name the 5ARIs (2)
Finasteride, Dutasteride
MOA of 5ARIs?
Inhibits 5α reductase (Type II) → ↓ conversion from testosterone → DHT → ↓ size of prostate
Advantages of 5ARIs? (4)
What must we do in regards to PSA levels?
- Slow progression of disease
- ↓ need for surgery
- ↓ PSA levels → consider adding if initial PSA > 1.5ng/mL
- Lesser risk of hypotension
Obtain PSA levels before initiation
When do we use 5ARIs?
- Moderate-severe LUTS with large prostate (> 40g)
- For pts who want to avoid surgery/ cannot tolerate s/sx of α-1 antagonist
Onset of 5ARIs?
Slow: 6-12 months
ADEs of 5ARIs? (4)
- Ejaculatory disorders: ↓ semen during ejaculation/ delayed ejaculation
- ↓ libido (3-8%)
- ED (3-16%)
- Gynecomastia and breast tenderness (1%)
Name the Phosphodiesterase 5 inhibitor (PDE5I) (1)
Tadalafil
When is PDE5I used?
- Add-on Tx
- Especially for pts also with ED (helps with ED on top of BPH)
Advantage (with regards to when to take the drug) (1) and disadvantages (2) of PDE5I?
Advantage:
- Take without regards to timing of sexual activity
Disadvantage:
- Does not reduce prostate size
- Does not improve urine flow rate
Onset of PDE5I?
Days-weeks
ADEs of PDE5I?
Significant hypotension
Can PDE5I be used as monoTx?
Strength and dosing?
Yes.
Tadalafil 5mg OD.
Use for pts with younger age, lower BMI and higher baseline s/sx
What are the 3 different combination Tx?
- α-1 antagonist + 5ARI
- 5ARI + PDE5i
- α-1 antagonist + PDE5i
In which pts would combination tx be effective?
Pts with moderate s/sx (ie IPSS 8-19, IPSS QoL 5-6) and prostate size > 25g
Elaborate on α-1 antagonist + 5ARI
- For symptomatic pts with enlarged prostate
- Complement each other well → α-1 antagonist onset is weeks, while 5ARIs is months
- After 6 months, α-1 antagonist can be discontinued in moderate BPH
Elaborate on 5ARI + PDE5i
Benefits? When should we NOT initiate PDE5i?
- Beneficial to mitigate sexual ADEs that arise from 5-ARIs/ concomitant ED
- Individuals with BPH and ED often have cardiac co-morbs → if unstable angina, do not initiate on PDE5i (contraindicated with nitrates)
Elaborate on α-1 antagonist + PDE5i
Do we choose the nonselective or uroselective α-1 antagonist?
What must we take note about the dosing?
Does it help to reduce prostate size?
- Only use uroselective α-1 antagonist (use with nonselective α-1 antagonist → severe life-threatening hypotension)
- Must optimise/ stabilise α-1 antagonist dose first before adding PDE5i + use lowest effective dose of PDE5i
- Does not help to reduce prostate size
Name the most commonly used anti-muscarinic
Oxybutynin
MOA of anti-muscarinics?
When are anti-muscarinics used?
What must you take note of PVR?
MOA: block muscarinic receptor in detrusor muscle → ↓ involuntary contraction of bladder
For pts with irritative voiding s/sx (overactive bladder) → helps them pee less
ONLY use if PVR < 250ml (or 150ml better)
Non-pharmacological Tx for BPH?
- Limit fluid intake in evening
- Minimise caffeine and alcohol intake
- Educate pt to take their time to empty bladder completely and often
- Avoid medications that exacerbate s/sx
