U.S. drug giants Eli Lilly and Icos Corp. plan to seek regulatory approval to market a one-a-day version of their impotence-fighting drug Cialis.

Icos has applied a similar approval in Europe, reports The New York Times.

Icos Chief Executive Officer Paul Clark was quoted as saying the companies want to market the once-daily version to men in their 40's and 50's who take impotence drugs frequently. Currently, men take the drug up to six times a month.

The new version is designed to provide more spontaneity in sex life instead of the strategic planning needed in the "on demand" version, Icos said.

Icos expects the daily version of Cialis to generate 50 percent more revenue than the on-demand version. Analysts expect the daily version to be priced at about $3.50 a pill, or $100 a month, compared to about $12 a dose for the current version, the report said.

Copyright 2006 by United Press International