Medications that interfere with male fertility
Male fertility can be adversely affected through any of 5 basic mechanisms:
- Direct toxic effects on the testicles,
- Disruption of the pituitary gland and its stimulation of the testicles,
- Direct effects on ejaculation and/or erectile function,
- Decrease in libido (sex drive)
- Blocking the sperm’s ability to fertilize an egg
Medications that have a direct toxic effect on the testicles can damage the cells which produce sperm. This can result in lower sperm counts or in severe cases – cause a complete absence of sperm. Damage to the sperm producing cells can be temporary or permanent.
Normally, the pituitary gland, which is located just beneath the brain, will produce hormones that will stimulate the cells in the testicles. These cells will, in turn, produce sperm and produce hormones such as testosterone. The testosterone that is produced, along with some other hormones from the testicles, will regulate the level of stimulation to the testicles.
In some cases, medications may disrupt the connection between the pituitary gland and the testicles and result in inadequate stimulation to the testicles. This can result in lowered sperm counts and abnormal hormone levels.
In order for sperm to be delivered into the female reproductive tract, the male must be able to achieve an erection and subsequently, he must ejaculate. The coordination of these events is very complex and can be disrupted in a number of different ways.
Some medications may act to decrease male sexual interest in intercourse, or libido. Other medications may interfere with the ability of a man to get an erection or ejaculate.
Finally, some medications may affect the sperm directly. For example, a group of medications which are commonly used to treat high blood pressure called calcium channel blockers have been shown in some studies to block the ability of the sperm to fertilize an egg.
Listed below are several categories of medications and their effect on the five areas influencing male fertility. Men should not stop any prescription medication before discussing it first with his prescribing physician.
Recreational drugs
| Medication | Directly toxic | Affects pituitary axis | Decreased libido | Erectile dysfunction | Blocks fertilization |
| Alcohol | + | + | + | + | – |
| Cigarettes | + | – | – | + | – |
| Marijuana | + | + | – | – | – |
| Opiates | – | + | + | – | – |
| Cocaine | + | – | – | + | – |
Blood pressure medication
| Medication | Directly toxic | Affects pituitary axis | Decreased libido | Erectile dysfunction | Blocks fertilization |
| Thiazide diuretics | – | – | – | + | – |
| Spironolactone | – | + | + | + | – |
| Beta-blockers | – | – | + | + | – |
| Calcium channel blockers | – | – | – | – | + |
| Alpha blockers | – | – | – | + | – |
Hormone medications
| Medication | Directly toxic | Affects pituitary axis | Decreased libido | Erectile dysfunction | Blocks fertilization |
| Testosterone | – | + | – | + | – |
| Androgen blockers | – | + | + | – | – |
| Progesterone derivatives | – | + | + | + | – |
| Estrogens | – | + | + | + | – |
| Anabolic steroids | – | + | – | + | – |
Psychiatric medications
| Medication | Directly toxic | Affects pituitary axis | Decreased libido | Erectile dysfunction | Blocks fertilization |
| Anti-psychotics | – | + | + | + | – |
| Tricyclic anti-depressants | – | + | + | + | – |
| MAO Inhibitors | – | – | – | + | – |
| Phenothiazines | – | + | – | – | – |
| Lithium | – | – | + | + | – |
Antibiotics
| Medication | Directly toxic | Affects pituitary axis | Decreased libido | Erectile dysfunction | Blocks fertilization |
| Nitrofurantoin | + | + | – | – | – |
| Erythromycin | + | – | – | – | – |
| Tetracycline | – | – | – | – | + |
| Gentamycin | + | – | – | – | – |
Miscellaneous
| Medication | Directly toxic | Affects pituitary axis | Decreased libido | Erectile dysfunction | Blocks fertilization |
| Cimetidine | – | + | – | – | – |
| Cyclosporine | – | + | – | – | – |
| Colchicine | – | – | – | – | + |
| Allopurinol | – | – | – | – | + |
| Sulfasalazine | + | + | – | – | – |
