Updated

Federal health regulators are warning doctors not to prescribe high doses of the antidepressant Celexa, because of the risk of fatal heart complications.

The Food and Drug Administration said in an online posting that the drug can interfere with the heart's electrical activity at doses above 40 milligrams.

The label for Celexa previously stated that some patients should receive 60 milligrams, but the FDA has eliminated that language. "Studies did not show a benefit in treatment of depression at doses higher than 40 mg per day," the FDA states.

The new label will emphasize that Celexa should not be used in patients with congestive heart failure and other conditions that affect the heart's pumping action.

Drugmaker Forest Laboratories sells Celexa in doses of 10, 20 and 40 milligrams