Sildenafil
Side effects are generally mild and tolerable: headaches, hot flashes, heartburn, diarrhea, myalgias, hypotension, and dizziness. The drug may inhibit phosphodiesterase type 6 in the eye, with resultant difficulty in discriminating blue from green, bluish tones in vision, or difficulty seeing in dim light. Whether any adverse effect occurs in diabetic retinopathy or other eye diseases is yet to be determined.
Yohimbine tablets
Major side effects are uncommon, but minor symptoms, including headaches,
dizziness, insomnia, and anxiety, may occur in 25% of cases during the first
week of treatment. Patients who have blood pressure that is difficult to control
might notice a pressure increase.
Alprostadil
The major side effects, which occur in 3 to 10% of patients, are penile pain,
cavernosal scarring, or priapism.
Penile implants
Treatment failures attributable to infection, extrusion, or mechanical
failure, especially in patients with diabetes, previously were as high as 36%,
but better equipment and techniques have reduced these complications.