By Madeleine Castellanos, M.D.
Sexual arousal depends on a series of different mechanisms working in conjunction with each other in response to physical and/or psychological stimulation. Successful sexual arousal and performance relies on the participation of your brain, your nerves, your hormones and your blood vessels. Since medications that are used to control high blood pressure have their effect primarily on blood vessels, they can easily cause sexual side effects. Here are some of the more common anti-hypertensive medications broken down by type:
1. Diuretics: These medications work to lower your blood pressure by causing the body to eliminate excess fluid. By doing so, the actual volume of blood is decreased, which leads to a decrease in your blood pressure. Studies suggest that there is a high prevalence of erectile dysfunction (ED) in men taking diuretics for blood pressure, especially in the first few years of treatment. What is interesting is that after several years, the amount of men reporting ED who weren't taking diuretics almost matched those men who were taking diuretics. This suggests that the diuretic itself is not directly causing the ED, but the lowered blood volume is uncovering another existing problem with the blood vessels needed for an erection. These medications also lower zinc levels, which leads to a decrease in testosterone production and negatively affects sexual desire and performance. An example of diuretics are the thiazides.
2. Beta Blockers: In order for an erection to occur, there has to be activation of beta-receptors in the tissues of the penis and arteries of the penis. Some beta blockers bind to many different type of beta-receptors and can often block those receptors (beta-2). That does not allow the blood vessels to relax enough to allow the penis fill up with blood for a proper erection. Propanolol, timolol and nadolol are non-selective beta blockers and have the most potential for interfering with an erection. Beta blockers that are called "cardio-selective" are those that only block the beta-1 receptors and do not tend to cause ED. Examples of cardio-selective beta blockers are metoprolol, acebutalol, esmolol, and atenolol. Some beta blockers also block certain alpha receptors as well, which can cause ED. Examples of these are carvedilol and labetalol. But there are some beta blockers that can actually help erectile function by increasing nitric oxide (NO) levels with their alpha-blocking properties, such as nebivolol. Interestingly, studies have shown that just having anxiety about having side effects is enough to produce the side effect. Studies also have demonstrated a placebo (sugar pill) worked just as well as Viagra to get rid of the ED associated with beta blockers.
3. ACE Inhibitors: These blood pressure medications do not tend to cause ED, and in some instances, can even improve erectile functioning. Examples of these medications include losartan, candesartan, and valsartan.
4. Calcium Channel Blockers: These medications do not seem to adversely affect erectile functioning. Men taking this type of anti-hypertensive medication had the same rate of ED as those men of similar age not taking them. Examples of calcium-channel blockers are amlodipine, nifedipine, diltiazem, and verapamil. Some people have reported a decreased libido on these medications, however.
As always, prevention is always preferred over treatment of a condition. Maintaining an appropriate weight, getting good sleep, learning how to respond rather than react to stress, practicing aerobic exercise at least three to four times per week, and lowering your salt and fatty food intake are all lifestyle choices that keep your body's functioning more in balance. If you can put these into practice early in life, you decrease your chances of having ED from any vascular disease, as well as decrease your chances of having to be on blood pressure medications later in life.