Impotence is a condition in which a man cannot achieve or maintain an erection. An erection requires a specific sequence of events starting with hormones alerting the brain to sexual arousal, which triggers nerve signals to be sent between the brain, spinal cord and penis. This sets off a series of chemical reactions that result in the smooth muscles surrounding the blood vessels within the penis to relax, changing the flow of blood into and out of the penis. Any medication that interrupts any part of this process can result in impotence.
Beta Blockers
Doctors prescribe beta blockers to treat high blood pressure, congestive heart failure and chest pain. These medications, which include propanolol, metoprolol and acebutolol, block adrenaline from binding to receptors in the heart. The body releases adrenaline, also called epinephrine, in response to stress. Adrenaline increases heart rate and constricts blood vessels. Beta blockers inhibit this action, slowing the nerve impulses and allowing the heart to beat slower and opening up blood vessels to allow blood to flow.
Although helpful in treating conditions involving the heart, beta blockers can also affect the processes necessary to produce an erection. By slowing nerve impulses to the penis and reducing the flow of blood, beta blocker medications can lead to impotence.
Diuretics
Diuretics, commonly called water pills, also effectively treat high blood pressure and congestive heart failure as well as kidney diseases. Diuretics induce the kidneys to filter excess fluids and salts from the blood. This reduces the volume of blood, therefore reducing blood pressure and easing the workload on the heart.
Doctors may prescribe one of several different types of diuretics. Thiazide diuretics, which include the medication chlorthiazide, most commonly contributes to impotence.
Antidepressants
Depression and impotence have a cause and effect relationship. Many patients who suffer from impotence develop depression while those who suffer from major depressive disorder may experience impotence as a symptom. Medications used to treat depression can also cause or worsen sexual dysfunction, including impotence.
Early generation antidepressant medications, including monoamine oxidase inhibitors and tricyclic antidepressants, frequently cause erectile dysfunction, according to a study published by Drs. Rosen and Marin in the "Journal for Clinical Psychiatry." Newer antidepressant medications, classified as serotonin reuptake inhibitors, cause fewer life-threatening side effects, but 10 to 15 million patients taking these medications will still experience some sort of sexual side effect, report Rosen and Marin.
