INTERVIEW-Wyeth sees big Pristiq sales, despite slow start

* Wyeth says insurer resistance to Pristiq tougher than expected

* Says $15.7 million second quarter sales do not reflect true demand for product

* Sticks to $1 billion annual sales forecast

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By Ransdell Pierson

NEW YORK (Reuters) - Wyeth WYE.N on Wednesday said insurers have been more reluctant than expected to reimburse patients for its recently approved Pristiq depression drug, but the company stuck to its forecast of eventual $1 billion-a-year sales for the product.

"The resistance upfront (from insurers) has probably been tougher than we anticipated, but we think there are opportunities to work through that," Joseph Mahady, head of Wyeth pharmaceuticals, said in an interview.

He said insurers have shown resistance, including requiring patients to pay relatively high co-payments for Pristiq, because it is competing with less expensive generic forms of other depression treatments.

Pristiq, a derivative of Wyeth's Effexor antidepressant, was approved by U.S. regulators early this year and introduced into U.S. drugstores in May.