Health insurer Aetna Inc. said on Monday it is not paying any claims for Bextra, a pain reliever that the FDA requested to be removed from the market, for prescriptions as of April 7.

The Hartford-based company said it is contacting more than 33,000 customers who have used Bextra to inform them of the U.S. Food and Drug Administration’s (FDA) decision to ask that Bextra be withdrawn from the market.

Pfizer Inc. agreed to suspend sales of Bextra after U.S. and European regulators said the side effects, including a potentially fatal skin allergy, outweigh the benefits.

Aetna Pharmacy Management has instituted computer system edits that will automatically block Bextra prescriptions from being paid.

Besides the direct communications, Aetna Pharmacy Management will communicate the news concerning Bextra and increased warnings the FDA is requiring of all Cox-2 inhibitors and non-steroidal anti-inflammatory drugs, such as ibuprofen and naproxen, on its corporate and pharmacy Web sites in an attempt to reach all members.

The FDA has been studying the safety of Cox-2 inhibitors since Merck & Co. Inc. voluntarily recalled Vioxx in September 2004 after a clinical study showed an increased risk of cardiovascular problems.