Drugs to Treat Erectile Dysfunction

With the approval of avanafil (Stendra), a fourth drug has joined the pack in the battle against erectile dysfunction (ED) alongside sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra). So it’s a good time to take a look at how effective and safe these drugs are and whether they’re right for you.

How do ED drugs work?

They all work by inhibiting an enzyme called phosphodiesterase type-5 (PDE5). Blocking this enzyme causes the blood vessels in the penis responsible for achieving and maintaining an erection to dilate. However, no erection will occur without  an environmental or psychological trigger to stimulate sexual arousal.

Who gets ED?

It’s important to distinguish between ED and other types of sexual dysfunction, such as decreased libido or abnormal ejaculation. ED refers specifically to the inability to acquire or maintain an erection, either occasionally or consistently.

The risk factors:

• Age – The incidence rises from less than 10 percent in men aged 20 to 30 to more than 35 percent in men over 70.
• Lifestyle – Smoking, inactivity, and obesity can lead to ED.
• Underlying diseases – Diabetes, cardiovascular disease, and sleep apnea increase your risk.
• Drugs – Some drugs, particularly antidepressants, can cause ED.

Finally, it is important to recognize that many men without any of these risk factors can have ED. Psychosocial stress may play a role, and while low testosterone won’t necessarily cause ED, some men with low testosterone levels do find that testosterone replacement therapy can improve erectile function.

How effective are these drugs?

Very effective. Studies have shown that 60 to 70 percent of men with ED see positive results.

Is one drug better than another?

For the most part, no. They’re what doctors sometimes call “me-too” drugs–drugs that are largely interchangeable. However, some men may benefit from one and not another for reasons that aren’t fully understood.

Some basic differences:

• Cialis has a longer time until onset–45 minutes, compared to 30 minutes for Viagra and Levitra, and even less than 30 minutes with Stendra.
• Cialis lasts much longer–up to 36 hours compared to 4 hours with the other agents.
• High-fat meals can delay absorption and the onset of action of all but Cialis.
• Side effect profiles are similar and most commonly include flushing, headache, runny nose, dizziness, and upset stomach. Less common side effects include priapism (a prolonged erection), visual effects (notably “blue vision”), and transient hearing loss.
• Cialis can be taken daily, so it’s best for men with consistent ED.
• All these drugs (including Cialis in a higher dose) can be used on an as-needed basis.

Who shouldn’t take these drugs?

These drugs can dangerously lower blood pressure and lead to a potential heart attack if you’re taking nitroglycerin. That also means you should be careful when combining them with other blood pressure-lowering substances like alcohol, some antihypertensives, and alpha-blockers, which are often used to treat prostatic hypertrophy and hypertension. Several of these drugs are metabolized by the liver or kidneys, so anyone with liver or kidney problems should avoid them. Always be sure to talk to your doctor about any drugs you’re taking or any other medical conditions you have.

Is it safe to take these drugs recreationally?

Dangerous drug interactions and potential health issues mean you shouldn’t take any of these drugs without a prescription and discussing them with your primary healthcare provider. Recreational use is common–most often to shorten the refractory period between erections–and the side effects are the same as when the drugs are used by men with ED.