Transurethral Agents - Erectile Dysfunction
Transurethral agents
What is a "transurethral agent"?
Transurethral agents, also called intra-urethral agents, are ED treatments whose mode of administration is insertion into the urine channel, known as the urethra. The only FDA-approved urethral suppository is called MUSE® (Medicated Urethral System for Erection), which contains the drug alprostadil (also used in the injectable drugs, Caverject and Edex).
How are urethral suppositories inserted?
A tiny medicated pellet, roughly the size of a grain of rice, is inserted approximately one inch into the opening at the top of the penis, while the man is standing, using an applicator. Once effectively inserted, the tissue of the penis absorbs the suppository. To help aid insertion and administration of the suppository into the urethra, lubrication can be achieved by inserting the pellet directly following urination. To minimize leaking and promote absorption, the patient is also instructed to hold the penis upright and massage gently and to stand, sit or walk for 5 to 10 minutes while the medication is being absorbed and an erection develops.
How do urethral suppositories work?
Alprostadil (MUSE) belongs to a group of medicines called vasodilators that increase blood flow by causing blood vessels to expand. Once MUSE is inserted and absorbed into the tissue immediately surrounding the urethra (the corpus spongiosum) it is transferred into the erectile chambers (corpora cavernosa) through small veins. The medicine then causes the erectile tissue to relax and allows blood flow to increase. This increased blood flow causes an erection.
MUSE is prescribed in one of four dose strengths (125, 250, 500, and 1000 mg), although the lower doses tend not to be effective in the average man with ED. MUSE is usually only recommended as a single daily dose.1
MUSE usually begins creating an erection in about five-to-10 minutes. Sexual activity should be attempted within 10 to 30 minutes after using the medicine. It is not uncommon for the erection to continue after ejaculation,1 although loss of the erection is expected within one hour. A doctor should determine the correct dose of MUSE.
How effective are urethral suppositories?
MUSE has an average overall success rate of 35%, in achieving an erection sufficiently rigid for sex. While urethral suppositories are often less intimidating to men than injecting medicines into the penis, it can still be a complex process and should be taught in the clinician's office before a man begins to use MUSE at home.
What are the side effects or potential complications of urethral suppositories?
The most common side effects are pain and minor discomfort in the penis and perineum (area between scrotum and rectum) and dizziness. These side effects are reported in less than 5% and 2% of men, respectively, and often go away during treatment as the body adjusts to the medicine. Because of the potential for dizziness, it is often recommended that the first dose of the agent, particularly 500 or 1000 mgs, be given in the physician's office.
Rare side effects that can occur requiring a doctor's immediate attention include an erection continuing for over four hours (known as priapism) or an erection becoming painful.
When using alprostadil in its suppository form, it is important to use a condom when having sexual intercourse with a pregnant female. Although harm to the fetus is unlikely, using a condom will protect the fetus from exposure to this medicine. If a woman can become pregnant, use of contraceptive methods is recommended because the effects of this medicine on early pregnancy are not known.
What is the cost of urethral suppositories?
Depending on the dose of MUSE prescribed, it may cost anywhere from $125 to $175 for six urethral suppositories. The cost of treatment with healthcare coverage varies according to provider or plan.
