Medications: Many common medicines produce erectile dysfunction as a side effect. Medicines that can cause erectile dysfunction include many used to treat high blood pressure, antihistamines, antidepressants, tranquilizers, and appetite suppressants. Examples of common medicines that can cause erectile dysfunction include propranolol (Inderal) or other beta-blockers, hydrochlorothiazide, digoxin (Lanoxin), amitriptyline (Elavil), famotidine (Pepcid), cimetidine (Tagamet), metoclopramide (Reglan), naproxen, indomethacin (Indocin), lithium (Eskalith, Lithobid), verapamil (Calan, Verelan, Isoptin), phenytoin (Dilantin), gemfibrozil (Lopid), amphetamine/dextroamphetamine (Adderall), and phentermine. Prostate cancer medications that lower testosterone levels such as leuprolide (Lupron) may affect erectile function. Some chemotherapies such as cyclophosphamide (Cytoxan) may affect erectile function.
Penile Injection Medication: This is just what it sounds like. Injected at home directly into the penis, the medication alprostadil produces erection by relaxing certain muscles, increasing blood flow into the penis and restricting outflow. Although some sources report an 80 percent success rate, the therapy has disadvantages, such as risks of infection, pain, and scarring—fibrosis—in the penis, and it may also cause priapism. A popular version of this medication is Upjohn Corporation’s Caverject. The MUSE System, by VIVUS, involves the same medicine (a pellet of alprostadil) applied with an eye-dropper-like applicator, directly into the urethra.
For patients who have ED related to hypertonic cavernous smooth muscle and excessive sympathetic discharge, we recommend a trial of a low-dose alpha adrenergic blocker, such as terazosin 1 mg PO at bedtime nightly. We typically increase the dosage as needed every 2–3 weeks for 3–5 months until the patient experiences improvement of the erection or we determine that treatment is ineffective. We explain the potential side effects of orthostasis, dizziness, and retrograde ejaculation in detail. We also take great care and time in explaining to the patient, and his family/partner if present, the pathophysiologic mechanism of their erectile dysfunction and the biological basis of the treatment plan. This detailed discussion helps to engage the patient in the treatment plan and provides encouragement regarding the potential for response to treatment and recovery. During these encounters, we utilize teaching tools, such as diagrams, drawings, printed handouts, and other visual aids to ensure that the discussion is patient-focused and patient-friendly. Patient education is critical to exploring treatment options and developing confidence in our ability to treat the ED, and their own ability to overcome and eventually resolve the problem of ED.
Multiple authors have demonstrated that anxiety, depression, and stress clearly produce major neurochemical and neuroendocrine changes in the brain (10,11). Changes in neurobiology would be expected to contribute to impaired erectile function. Stress and anxiety lead to increased epinephrine production, and heightened sympathetic tone leads to exaggerated cavernosal smooth muscle contraction, inability of smooth muscle to relax, and subsequent erectile dysfunction (6,7). Failure to achieve a fully rigid erection may aggravate performance anxiety leading to a vicious cycle.