Contrary to popular belief among physicians and patients, the family of hypertension drugs known as beta-blockers does not prevent development of colon and rectal cancer, German researchers reported Monday. In fact, long-term use of the drugs might even be associated with an increased risk of developing an advanced form of the disease, they said.
Beta-blockers are a family of drugs that reduce blood pressure and improve heart function by reducing the body's response to stress hormones such as epinephrine and norepinephrine. Among the best known are atenolol (Tenormin), bisoprolol (Zebeta), metoprolol (Lopresor or Toprol) and carvedilol (Coreg). Because studies in animals and cell lines have shown that norepinephrine increases the growth rate of certain tumors, such as breast and colon cancer, researchers have speculated that beta-blockers might inhibit growth of the tumors by inhibiting norepinephrine response. Several small trials in humans, however, have produced mixed results.