Allergan, Medicis Shares Drop on Botox Probe

Regulators said they're reviewing the safety of Allergan'sBotox and a competing product after reports of deaths and serious reactions in some patients, knocking down shares of the pharmaceutical company and a would-be competitor.

The Food and Drug Administration said the most serious cases included hospitalizations and deaths and occurred mostly in children treated for cerebral palsy-associated limb spasticity, a use not approved in the United States. (See the on-air report at left.)

The FDA said its review applied to Allergan's Botox and Botox Cosmetic, and privately held Solstice Neurosciences' Myobloc.

After the announcement, Allergan shares fell more than 5 percent on the New York Stock Exchange

Shares of Medicis Pharmaceutical, which has been trying to win FDA approval for a Botox competitor called Reloxin, dropped about 5 percent as well.

- Reuters contributed to this report.