Drug classes used in treatment of benign prostatic hypertrophy
Alpha Blockers
- Reduces tension of prostatic smooth muscle
5-Alpha reductase inhibitors
- Reduces size of prostate gland
- Treatment of 6-12months usually needed to reduce size sufficiently
Examples of Alpha Blockers used in BPH
- Terazosin
- Tamsulosin
- Doxazosin
- Alfuzosin
Examples of 5-Alpha reductase inhibitors
- Finasteride
- Dutasteride
Can 5-Alpha reductase inhibitors and alpha blockers be given together to trea BPH?
Yes, greatest reduction in BPH symptoms such as acute urinary retention, urinary incontenence, renal insufficiency, recurrent bladder infections
Mechanism of action of Tamsulosin
Selective competitive antagonism of lower urinary tract
alpha-1 adrenergic receptors, relaxing smooth muscle of
the bladder neck and prostate resulting in improved urine
flow
Indications of Tamsulosin
(Alpha 1 antagonist)
- BPH
- Nephrolithiasis (kidney stones-relaxes urethra)
Adverse effects of Tamsulosin
(Alpha 1 blocker)
- Sinusitis
- Dizziness
- Pharyngitis
- Cough
- Infection
- Orthostatic hypotension
- Syncope
Ocular
- Intraoperative floppy iris syndrome
Cautions for use of Tamsulosin
(Alpha 1 antagonist)
- Glaucoma surgery
- Cataract surgery
- Sulphonamide allergy
Mechanism of action of Finasteride
(5-alpha reductase inhibitors)(androgen)
Inhibits type II 5-alpha-reductase, interfering with conversion of
testosterone to 5-alpha-dihydrotestosterone
Indications of Finasteride
- BPH
- Male pattern baldness
Adverse reactions of Finasteride
(5-Alpha reductase inhibitors)
- Orthostatic hypotension
- Angioedema
- Prostate cancer(increased testosterone)
- Breast cancer(increased testosterone)
*
Major side effects of 5-Alpha reductase inhibitors
- Lower libido
- Erectile/ejaculatory dysfuction
