The largest drugstore chains have been in a legal battle with Pfizer ($PFE), accusing it of conspiring to keep generics of its antidepressant Effexor XR out of their stores for years. Now they will have to deal with losing some of the real thing. Pfizer is recalling three lots of the drug after a pharmacist discovered a capsule of one of Pfizer's heart pills in an Effexor XR bottle, a potentially fatal combo.