“The new black box warns of the risk of tardive dyskinesia, a neurological disorder that causes muscle spasms and repetitive movements. The risk grows with prolonged use of the drug or with high doses of it, and it usually continues even after the drug is stopped, the warning states. ”The chronic use of metoclopramide therapy should be avoided in all but rare cases where the benefit is believed to outweigh the risk,” said CDER chief Janet Woodcock.”