If oral prescription medications, PDE5 inhibitor pills such as sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra), no longer work for you or they produce intolerable side effects, then you may want to consider Penile Injections.
Penile Injections for treatment of ED are called Intracavernosal Injections (ICI), because you inject within the corpus cavernosum – the erectile tissue of the penis.
The injection solution is a mixture of two or three medications in a sterile vial. The possible medications are alprostadil (also called prostaglandin E1, or PGE1), papaverine, and phentolamine.
Alprostadil in 1995 became the first FDA approved medication for erectile dysfunction. In penile injection therapy, it is sold under brand names as Caverject, Edex or Muse. Alprostadil triggers direct corporal artery vasodilation by increasing intracellular cyclic adenosine monophosphate (cAMP) levels. It keeps the blood flowing into the penis to create and maintain erection.
Papaverine is a nonspecific phosphodiesterase inhibitor, which is the same class of drugs as Viagra and Cialis. Serendipitously, it was the first drug found to be effective for Erectile Dysfunction.
Phentolamine is an alpha-1-adrenergic antagpmost that opposes sympathic-mediated constriction of cavernosal arterial inflow - it keeps your arteries open and blood flowing into the penis.
Mixtures of all three ingredients are commonly referred to as Trimix, while mixtures of just papaverine and phentolamine are commonly referred to as Bimix. They have been in use since 1983, and 70% of men are satisfied.
These penile injections are also viable options for men with diabetes, spinal cord injury, multiple sclerosis, and other neurogenic conditions.
The preferred route is via Penile Injection using a diabetes syringe and needle into the shaft of the penis. Injections are delivered with a fine-gauge diabetic needle (eg. a 29-gauge needle) inserted midshaft at the 2 o’clock or 10 o’clock positions. It is painless and convenient. As an alternative, there are Trimix Gels or Bimex Gels marketed as needleless Trimix. The tradeoff is that they are only 40% effective.
Bimix comes in various strengths. The formulas consist of papaverine/ and phentolamine, and are listed below starting from weakest to strongest:
We often use a 30 mg/mL + 1 mg/mL mixture.
Because it lacks prostaglandin, Bimix is a good option for patients with autonomic neuropathy such as in diabetes, with resultant PGE1 hypersensitivity who have the potential to experience penile pain associated with trimix or alprostadil injections.
Trimix consists of alprostadil, papaverine, and phentolamine. Trimix is categorized as Standard concentrations or Low Alprostadil concentrations.
Alprostadil can cause an ache in the penis in 20% of men. Although it is harmless, the pain may interfere with enjoyment of the erection, and your doctor may change your prescription to a low alprostadil trimix. Standard and Low Alprostadil concentrations are listed in order from the weakest to the strongest:
STANDARD (Alprostadil/ Papaverine/ Phentolamine)
LOW ALPROSTADIL (Alprostadil/ Papaverine/ Phentolamine)
We recommend starting with the lowest dose of Alprostadil. An appropriate starting dose is 2.5 micrograms. with increments of 2.5 micrograms. until the lowest effective dose is achieved. Actually, 80% of men can achieve a satisfactory erection with 5 micrograms.
We often use a 10 mcg/ 30 mg/mL/ 1 mg/mL mixture.
We recommend starting off at 15 units. Trimix usually takes 5-20 minutes to achieve the maximum effects. If you do not get an erection after 20 minutes, do not inject more Trimix. Your dosage can be adjusted, but you should always wait at least 48 hours between injections. You may increase your dose by five units each time until you get the effect you want. If you are using 50 units and not getting the erection that you need, call us and we will prescribe you a stronger dose.
For most, an erection usually lasts for about one to two hours, but erections after using Trimix can sometimes last much longer. After 2 hours, we recommend cooling the penis to reduce the erection. Alternatively, after two hours either terbutaline 5 mg (Brethine) or pseudoephedrine 60 mg orally by mouth may be of benefit. In case your Trimix injection results in an erection that lasts longer than three hours or is painful, you should contact your doctor or go to an emergency room. This condition is called priapism and left untreated, can result in damage to the structure of the penis. The incidence of priapism with Trimax ranges from 0% to 3.7%, and thus the importance to start at the lowest dose, and not make adjustments sooner than 48 hours. We will prescribe phenylephrine specifically for priapism. Phenylephrine can counter the effect of the Trimix. For priapism, inject 200 µg every 3-5 minutes until tension and swelling are relieved. The maximum dosage is 1 mg within 1 hour. Lower doses are recommended in patients with severe cardiovascular disease
We allow a maximum of three injections per week, but you must wait 48 hours before taking another dose. And make sure you alternate between sides of the penis for each injection. Injecting too often can cause fibrosis or thickening and scarring of connective tissue. This can cause the penis to curve to the side if one side of the penis has scar tissue.
However, injection therapy is not always a good long-term option for some men and that is when they may want to consider a penile implant.
The syringe is the plastic part of the device that holds the liquid. Printed gradations on the syringe allow you to measure a certain volume (amount) of liquid (your dose). Syringes are available in three different volumes:
Step-by-step instructions detailing how to properly use your penile injection at home without a doctor.
1. Tear open an alcohol swab and wipe the rubber top of the bottle to sterilize it.
2. Peel open the syringe carefully and remove the protective cover from the needle. It is important that you do NOT contaminate the needle with anything but the rubber bottle cap.
3. Push the needle through the rubber stopper, then flip the ampule (the glass container of medication) upside down. Pull on the plunger until you withdraw the prescribed amount of medicine.
4. As you continue to hold the ampule upside down, inject whatever air remains in the syringe into the ampule.
5. Withdraw the fluid until there are no more air bubbles in the syringe and the correct amount of medication is in the syringe.
6. Pull the needle out of the ampule and lay the syringe on the edge of a flat surface. Make sure the needle hangs over the edge to keep it from touching anything.
7. Grasp the head of the penis between the index finger and thumb and gently pull the penis away from your body until the skin is tight.
8. When choosing an injection site, avoid any area where a vein is clearly visible. We recommend changing injection sites from left to right as well as up and down the shaft and back again to ensure that you do not develop scar tissue at one specific site.
9. Wipe the skin with an alcohol swab.
10. Pick up the syringe with the other hand and position your hand like you're about to throw a dart.
11. Touch the point of the needle to the place you want to inject. This is at the 2 and 10 o'clock position. (Only inject your penis while you're sitting or standing.)
12. Hold the syringe at a 90-degree angle and push lightly to penetrate the skin near the base of your penis.
13. Once you've poked through the skin, you will feel some resistance. Push firmly forward until a distinct "give" is felt. The needle should now be in the right place (within erectile bodies). The whole length of the needle should be also be in.
14. Hold the syringe between your index and middle fingers and place a thumb on the plunger to inject the entire contents of the syringe. Then take the needle out of your penis.
15. Immediately apply pressure to your penis with your thumb and index finger for two to three minutes using the alcohol swab. Wait until there is no bleeding.
16. Place the needle in the disposal box.
Intraurethral gel therapy is done by placing medication into the urethra through the opening at the head of the penis prior to having intercourse.
This tends to be a stronger therapy than oral medications like tadalafil (Cialis) and sildenafil (Viagra), but weaker than the penile injections.
Intraurethral gel for the treatment of ED is composed of a mixture of Bimix or Trimix.
Gel therapy should be used 5 minutes prior to intercourse. Place the gel into the urethra using a pre-loaded, needle-less syringe, holding the medicine in place while performing urethra massages. Allow the medicine to absorb for a few minutes, then drain as much of the medicine as possible from the urethra prior to sex. Start with half of the dose in the syringe initially and increasing the dose to the entire syringe if the medicine doesn’t achieve an erection firm enough. Physical stimulation will help, but is not necessarily required to achieve an erection. The resulting erection should last through the entirety of sex, but less than an hour. Seek immediate medical attention at an emergency department if the erection lasts longer than 4 hours. Recommend using Intraurethral gel therapy no more than once in a 24-hour period.
The main side effects are priapism or a prolonged erection, hematoma, and scarring. A complete list of side effects are listed below.