Treating Erectile Dysfunction - A Review of Oral and Injectable Medications and Cutting Edge Treatments

As we discussed in our initial post about this topic, over half the male population reports some level of erectile dysfunction (ED). Because it is so prevalent, much attention has focused on the subject and today there are a number of treatment options available that can help men initiate and maintain an erection. The following is a review of oral medications and injectable medications as well as more cutting edge and experimental approaches to treating ED. 

Oral Medications (PDE-5 Inhibitors)

The four most popular medications used today to treat ED include sildenafil (Viagra), vardenafil (Levitra), tadalafil (Cialis) and avanafil (Stendra). This class of medications work via the same mechanism - they block an enzyme called phosphodiesterase which in turn prolongs the action of vasodilating chemicals, one of which is nitric oxide. In addition to vasodilating properties, PDE5 inhibitors relax smooth muscle, improving profusion to the blood vessels. These medications work in different areas of the body including the lungs and genitals.  This class of medications was originally used for pulmonary hypertension (a lung condition) and was observed to also improve erectile function.

Because they act similarly, potential side effects for all four medications are comparable and include headaches, muscle aches, vision changes, nasal congestion, flushed skin, and heartburn. These side effects are usually mild and resolve within  three to five hours. Mild side effects do not preclude you from using the medication as needed.

The following is an overview of each:

Sildenafil (active ingredient in Viagra)

Sildenafil came on the market in the late 1990s and is one of the most common and widely used erectile dysfunction treatments available today. This drug works by increasing blood flow to the erectile tissue of the penis, making it easier to achieve an erection. The medication  usually starts to work within 30 to 60 minutes of consumption and works fastest on an empty stomach.  The effects last on average  for four to eight hours.  Taking Sildenafil following a bigger or higher-fat meal may inhibit or delay the efficacy of the medication.  The dosing ranges between 25 and 100 mg. Don’t be tempted to take more than 100mg. More is not necessarily better - it won’t result in this medication lasting longer and can cause side effects such as low blood pressure.

Tadalafil (active ingredient in Cialis)

Tadalafil was approved by the FDA in 2003 and is a longer-lasting ED drug that provides similar effects to sildenafil. Tadalafil remains active for up to 36 hours after it's taken, making it the longest-acting of the erectile dysfunction drugs available today. Additionally, Cialis can be taken two ways, as a low daily dose (between 2.5 - 5mg) or in as-needed doses (between 5 - 20mg). These benefits can make tadalafil a more attractive alternative as you don’t need to take the pill directly before sexual activity. Instead, it can be taken daily at a low dose - allowing it to stay in your system, resulting in greater spontaneity. Again, more is not better. Taking more than 20mg per day can result in a rare but potential side effect called priapism - an erection lasting more than four hours that is considered an emergency.

Vardenafil (active ingredient in Levitra)

Vardenafil is another ED drug that works similarly to sildenafil and tadalafil. It has a similar half-life to Viagra (lasting approximately four to five hours). However, it takes approximately one hour to start working.

Avanafil (active ingredient in Stendra)

Avanafil is a new, “second-generation” ED drug. Just like sildenafil, vardenafil, and tadalafil, it’s a PDE5 inhibitor, improving blood flow to the penis and making it easier to get an erection.

Avanafil is a fast-acting medication, taking effect in just 15 minutes, and it lasts up to five hours. Though side effects similar to other ED medications (headaches, nasal congestion, and facial flushing) are reported, avanafil has a lower risk of causing these issues because it specifically targets the PDE-5 isoenzyme. 

These four oral medications are scientifically proven and widely used - and may be a good option to help address erectile dysfunction. Every man needs to find out which of these medications is the most effective - often using trial and error until landing on the best solution with the least side effects. Men should speak to a doctor familiar with sexual health to determine the best ED drug to meet their specific needs. 

Injectable Medications

PDE5 inhibitors like those listed above can sometimes fail in more severe cases of ED. And some men simply do not tolerate these medications due to side effects.In these cases, one option is to escalate to intracavernosal injections (i.e. a small insulin needle is used to inject medication directly into the penis.) When injected directly into the penis, certain drugs have been found to induce erections.  And while the thought of injecting a needle directly into your penis likely sounds daunting, a study reports that 70 percent of men are highly satisfied with this treatment option.

The downside of this treatment option is that you need to inject medication into your penis. The benefits are that this is often a very well-tolerated medication - the side effects listed above for oral medications are rarely seen with injectables because the medication acts locally, having less of a systemic effect. The most common and concerning potential side effect for this treatment option is priapism (or a prolonged erection).  With injectable medications, priapism happens more commonly than with oral and can result in a trip to the emergency room. Additionally, any time you poke yourself with a needle there is a possibility of scar tissue formation or the development of lumps or bumps at injection sites. These side effects can often be mitigated through proper injection training and appropriate dosing. Additionally, some men experience mild to moderate pain during the injection, a painful sensation with their erection or a small amount of bleeding at the injection site.

Below are four of the leading injectable medications used to treat ED. Typically, the first dose can be demonstrated under the supervision of a doctor in the office so that a patient feels comfortable administering at home thereafter.  The medication is injected through the skin, on one side of the base of the shaft of the penis, and most men report only slight discomfort during the injection.

TriMix

Most men begin injection therapy with TriMix, which is a mixture of three ingredients: alprostadil, phentolamine, and papaverine. These ingredients work by relaxing the smooth muscle and opening the blood vessels in the penis, causing an erection. The injection is self-administered, typically 5 to 20 minutes prior to planned sexual activity and the erection will typically last one hour.  

BiMix

BiMix combines only two of the ingredients used in TriMix: phentolamine and papaverine. This injection should produce an erection in 5 to 20 minutes and can be expected to last up to one hour.

Alprostatdil

Alprostatdil makes the blood vessels expand, boosting the blood flow throughout the body, including the penis. This drug rarely causes priapism, however, pain is more commonly reported in higher doses of alprostatdil.

MUSE

MUSE®  is another form of alprostadil. Instead of being an injectible, this version is a single-use, medicated transurethral system that delivers alprostadil to the male urethra. Alprostadil is formed into a medicated pellet that resides in the tip of a translucent hollow applicator and is administered by inserting the applicator stem into the urethra after urination. 

Cutting Edge / Experimental Treatments

PT 141 

Also known as Bremelanotide and sold under the brand name Vyleesi, this medication was approved by the FDA in 2019 to treat low sexual desire in women. However, according to a study, it shows promise for treating erectile dysfunction: “Administration of PT-141 to normal men and to patients with erectile dysfunction resulted in a rapid dose-dependent increase in erectile activity. The results suggest that PT-141 holds promise as a new treatment for sexual dysfunction.”

Instead of PDE-5 inhibitors like Viagra and Cialis, it does not act in the vascular system, but directly increases sexual desire via the nervous system. PT 141 is a melanocyte-stimulating hormone (MSH) which stimulates and activates the dopamine hormones that play a major role in sexual motivation.

It should be injected near the abdomen surrounding the skin with the help of an insulin syringe and should be used at least 45 minutes before anticipated sexual activity. Common side effects include nausea and headaches. This treatment is still fairly experimental in men and requires significant trial and error with timing and dosing.

Between oral medications, injectables and the more cutting edge therapies being introduced - there is a wide array of options to help address erectile dysfunction. It is important to note, however, that consulting your physician is paramount to finding a successful treatment option - and ensuring your particular health and needs are being taken into account.  If you have any questions about your sexual health or want to discuss erectile dysfunction treatments - just give the office a call at 425-209-1060.