Within just a few hours of the announcement that the FDA has approved Teva Pharmaceutical’s generic version of the best-selling antipsychotic, J&J Janssen’s unit has now announced that it will market an authorized generic - in other words, its own generic version of its own brand-name med.

The move is hardly surprising, given that Risperdal generated $2.5 billion in sales last year, accounting for 6 percent of companywide sales, and its follow-on Invega antipsychotic has yet to have the same impact in the marketplace. Moreover, other drugmakers have taken the same step to protect brand-name franchises from generic competition, most notably Merck, which launched a generic Zocor last year after the patent expired on its best-selling cholesterol pill.