Nigeria's largest state has sued US drug firm Pfizer for allegedly using 200 children as "guinea pigs" for a drug test in 1996 that led to multiple deaths and deformities, officials said Sunday...The state accuses Pfizer of "secretly using children as guinea pigs to test a drug under the guise of humanitarian gesture"...Pfizer was alleged to have administered an untested drug called Trovan Floxacin without authorisation on almost 200 children infected with meningitis in the state. Eleven of the children reportedly died, while the remaining 181 were said to have suffered from deafness, paralysis, brain damage and blindness.