Physician monitoring of drug side-effects affects not only the doctor's own patients, but is essential to warnings being placed on drugs and even the removal of drugs from the market, reported the study published in the journal Drug Safety.

Researchers from the University of California-San Diego studied 650 patients with side effects from statins -- the widely prescribed cholesterol-lowering drugs -- and found 87 percent of the patients said they spoke to their doctors about a possible connection between a statin and a symptom they experienced afterward.

About 50 percent of the time, patients said their concerns were either dismissed or not addressed. Patients reported their doctor told them: "These drugs have no side effects." "You're just getting older." "It's your imagination -- you just didn't like taking pills."

Physicians were less likely to acknowledge less common side effects -- where reporting is most important -- than the better known side effects, said lead author Dr. Beatrice Golomb.

"To ensure patient safety, we need to know as much as possible about a drug's effects -- favorable and possibly adverse," Golomb, said in a statement.