Allergan adopts 'poison pill' defense in Valeant takeover bid

The Botox maker is allowing shareholders to buy Allergan stock at a steep discount if any single investor acquires more than 10% of its shares.Takeover target Allergan Inc., the company that makes Botox, has adopted a "poison pill" defense intended to delay a buyout by Canadian company Valeant Pharmaceuticals International Inc. and activist investor Bill Ackman.