First women take the mifepristone to block the effects of the progesterone hormone, which keeps the pregnancy viable.
Similarly, antioxidant vitamins were thought to block the effects of oxygen molecules that could damage heart cells.
In the past, scientists have tended to focus on developing drugs that block the effects of harmful mutations.
"But do readers know that you cannot mix holistic treatment and chemotherapy because the holistic treatment might block the effects of the chemotherapy?
Doctors have experimented for decades with antiandrogens, which block the effects of sex hormones like testosterone and are most commonly used to treat advanced prostate cancer.
Other contaminants, like dioxins, can also block the effects of PCB's, said Dr. Stephen Safe, professor of toxicology at Texas A&M University.
Women whose tumours have high levels of oestrogen receptor, for example, benefit from drugs that block the effects of the oestrogen hormone.
Several new "targeted" cancer drugs, for instance, block the effects of genetic abnormalities that spur tumor growth.
The medications block the effects of heroin by binding to opiate receptors in the brain that heroin binds to; they are not anti-opiates.
Beta-adrenergic blockers (beta-blockers) block the effects of epinephrine (adrenaline), thus easing the heart's pumping action and widening blood vessels.
Rather than block a foreign substance, that vaccine would block the effects of a peptide hormone produced by the stomach called ghrelin that signals hunger in the brain.
