CORONA, Calif. (AP) — Watson Pharmaceuticals Inc. said Monday it is voluntarily recalling a drug it produced to treat irregular heartbeats because it may contain more of the active ingredient than specified. The drug, Propafenone HCL, came in 100-count bottles of 225 milligram tablets. The affected group of tablets was shipped to customers between Oct. 15 and Nov. 26 of last year. No other strengths or shipments are included in the recall. The lot is being recalled because some tablets may contain slightly higher levels of the active ingredient than specified. Watson said that some patients can be very sensitive to small variations in doses, and may experience potentially serious side effects. Anyone with this particular group of drugs should call (888) 352-9616, Monday through Friday, 8:00 a.m.-5:00 p.m. Eastern time, for instructions on how to return it.