Procardia (Nifedipine) appears to have contraceptive potential, and the calcium channel blocker also appears to cause reversible male infertility. The research stemmed from earlier observations that men who presented to infertility clinics were often taking a calcium channel blocker. Investigators noted the cholesterol content of the membrane was significantly reduced. Cholesterol synthesis significantly increased in sperm treated with nifedipine. The team subsequently determined that these drugs act by changing the cholesterol content of the membrane.
If you load sperm with cholesterol, you can make them nonfunctional, and that is what these drugs are doing. The idea of regulating sperm through cholesterol metabolism is not an idea that has been previously pursued. The researchers noted that if physicians have a male patient on a calcium channel blocker and they are experiencing difficulties with infertility, it is reasonable to try a different antihypertensive. Men should then wait approximately 3 months before attempting to impregnate their partner in order for new sperm to generate that have been unaffected by the calcium channel blocker.
Joint Annual Meeting of the American Society for Reproductive Medicine and the Canadian Fertility and Andrology Society September 1999 Toronto, Canada
Dr. Mercola's Comment:
An interesting side effect of a commonly used drug. There seems to be far better alternatives to calcium channel blockers for most people. One should consider seeking an alternative if they are taking one of these drugs.