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| |
| Erectile dysfunction |
| Physiology |
Erection requires a relaxation of the arteriole, allowing
inflow of blood being trapped in the corpus cavernous. |
| Causes of the dysfunction |
 | Neurogenic: Neuropathy, Myelopathy, Cauda equina lesion, CNS dysfunction |
| Vascular disease |
| Post traumatic: injury, radiation |
| Endocrine: hypothyroidism, hyperprolactinemia |
| Psychogenic |
| Medication: antihypertensives, anticholinergic, antidepressants,
antiandrogens, NSAID |
| Metabolic/Toxic: renal failure, alcohol, tobacco |
|
| Evaluation |
| Complete history and physical. |
| Nocturnal studies: Performed in a sleep laboratory. An erection would be
expected to occur with each REM episode. |
| Hormone testing:
 | testosterone level (both total and free), gonadotropins, and
gonadotropin-releasing hormone if clinical exam indicates lack of androgen stimulation.
|
| Symptoms and signs of low androgen levels: poor libido, small prostate
gland relative to the patient's age, small or soft testicles, noticeable thinning or
diminished growth of the beard. |
| If total testosterone level is low, check prolactin level to rule out
hyperprolactinemia. |
|
|
| Treatment |
| Functional Erectile dysfunction, counseling by a skilled sex therapist is
usually successful. |
|
Viagra (Sildenafil)
formulations:
Tab 25, 50, 100 mg
|
| Take while fasting, 30 to 60 minutes before intercourse |
| Side effects: facial flushing, headache.
|
| Do not use if taking nitrates
| e.g. nitroglycerin, isosorbide, tetranitrate |
| Hx of sickle cell, leukemia, multiple myeloma |
| abnormal shaped penis |
|
| Medication is a facilitator, not an initiator. The patient must,
therefore, have some Erectile function to facilitate.
|
| Further reading
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|
Caverject (Alprostadil)
Formulations:
pack of 6 vials
with diluent Available in 5, 10, 20 mcg single use
vials |
| Intrcavernosal injection |
| Self injection system
| syringe w diluent |
| inject into powder vial |
| remove med from vial |
| inject to side of penis |
|
| Side effect
| mild to moderate pain |
| bleeding |
| penile fibrosis 3% |
| priapism 0.4% |
|
| Further reading
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| Intraurethral suppository Alprostadil (Muse) therapy |
| 500 mcg tested in the office under supervision by physician. Then dose
adjusted to 250 mcg or 1000 mcg depending on response. |
| Systemic absorption is substantial. Up to 50% of patients have a
measurable drop in blood pressure, only about 3% are aware of it.
|
|
Trazadone (Desyrel)
|
| formulations: 50, 100, 150 mg |
| Usual dose 50 - 200 mg hs |
| Side effects: drowsiness |
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| Further reading |
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