Negligent, but not outrageous. Those words cost GlaxoSmithKline P.L.C. a $2.5 million judgment - but ruled out additional, punitive damages, in a Philadelphia courtroom last week. The case was the first of about 600 lawsuits to go to trial on claims that the company's Paxil antidepressant caused birth defects in children whose mothers took the drug during pregnancy.