Pharmacotherapy of Erectile Dysfunction Flashcards
Define Erectile Dysfunction
Inability to maintain penile erection sufficient for penetration to permit satisfactory sexual intercouse
Psychogenic Causes of ED
Generalized unresponsiveness or inhibition
Situational (performance)
Psychological (mood, stress)
Organic Causes of ED
Neurogenic (stroke, parkinson’s, DM, ETOH, Spinal cord injury)
Vascular (PVD, arteriosclerosis, HTN, trauma)
Hormonal (decreased T, hyperprolactinemia, hypothyroidism, hyperthyroidism)
Medication induced
Drugs that Induce ED
Anticholinergics Antidepressants Antipsychotics Dopamine antagonists Estrogens Antiandrogens CNS depressants Antihypertensives Cigarette and alcohol use
Diagnosis
Severity Complete medical and surgical history Review of meds PE Labs
International Index of Erectile Function
15 objective questions (erectile function, orgasmic function, sexual desire, intercourse satisfaction, overall satisfaction
5 categories of severity
PDE5 Inhibitors
First line therapy
Effective, PO, low side effect, discreet
PDE5 Inhibitor MOA
Normally PDE5 breaks down cGMP which increase calcium which causes SM contraction which decreases blood flow leading to flaccid penis
Inhibitors block this
***PDE6 Side Effects
Photoreceptor in the retine leading to increase sensitivity to light, blurred vision, loss of blue green differentiation
PDE11 Selective (Tadalafil) Side Effect
Skeletal muscle leading to back and muscle pain
PDE5 Inhibitor COntraindication
Nitrate use (hypotension)
PDE5 Inhibitor Precautions
Erection > 4 hours can lead to necrosis bc of lack of blood flow
CAD possibility (R vs B)
Hypotension and fluid depletion may be potentiated
PDE5 SE
Headache, dizzy, flushing dyspepsia Priapism (erection > 4 hrs) Hearing impairment Visual disturbances Back pain Nonarteritic anterior ischemic optic neuropathy
Nonarteritic anterior ischemic optic neuropathy
Blood flow blocked to the optic nerve
Rapid onset of painless unilateral vision loss
NAION RF
Other visual problems
Longer PDE5 Inhibitor use
PDE5 Inhibitor Interactions
CYP 3A4 inhibitors
Antihypertensives
Alcohol
Avanafil is good because
It avoids PDE6/11 inhibition
Viagra inhibits
PDE5/6 not 11
Levitra and staxyn inhibit
PDE5
6 minimally and not 11
Cialis inhibits
PDE 5 and 11 NOT 6
PDE5 Inhibitors Counseling
Engage in foreplay
Take on empty stomach
Avoid alcohol
Alprostadil MOA
Synthetic PGE1
Increase cAMP which causes SM relaxation and increase blood flow leading to prolong erection
Alprostadil Pros
Works on Multiple ED etiologies
Pretty good efficacy
Alprostadil Cons
Inconvenience (injection into penis/suppository)
Unnatural erection
Cost!!!
Alprostadil Contraindications
Anatomical deformity of the penis or predisposure ot priapism
Alprostadil Precautions
Bleeding disorder
Use of vasoactive agents (hypotension)
Cardiac health
Alprostadil Side Effects
Penile pain, cavernosal scarring, priapism, bleeding
Dizzy, hypotension
Alprostadil Injection Counseling
Room temp
Reconstitute prior to use
Inject 5-10 minutes before desire erection (last 1 hr)
Alprostadil Injections
Side of the penis so it gets to cavernosum (not head or tip) and change the side each time injecting
Alprostadil Suppository Counseling
Refrigerator
Empy bladder before use
Walk around to help erection develop (5-10 minutes) - last 1 hr
Vacuum Erection Devices (VED)
3 Parts (pump, cylinder, and tubing) Vacuum draws blood into the corpora cavernosa 30 minutes to start working First line in monogamous relationships Best in conjuntion with alprostadil
Hypogonadism
Low T in AM (<300)
Decreased libido, muscle strength, depression
Supplemental testosterone
Does not directly treat ED but improves libido (secondary ED)
Ideal testosterone replacement
achieve normal testosterone serum, circadian rhythm pattern (peak in AM) and androgen metabolites
Minimal side effects
Testosterone come in what formulas?
PO IM Transdermal Gels Implants
Testosterone should be caused in?
BPH and prostate cancer
Liver toxicity
Stop if no improvement in 3 months
Testosterone common side effects
Cardio
CNS (aggression)
Derm (acne)
Endocrine (wt gain, hypoglycemia)
IM Testosterone has
less frequent dosing but increased side effects
Topical patches
Good absorptions
Applied at night
Topical Gels
Shoulder upper arms ab NOT genitals
Apply in AM and let dry
Yohimbine
Herbal
Widely used aphrodisiac
Central alpha 2 antagonists (causes vasodilation)
NOT RECOMMENDED!!
