Feb. 13 (Bloomberg) -- U.S. Senate Budget Committee Chairman Judd Gregg said he will try to modify a law that expands prescription-drug coverage under Medicare starting in 2006 to trim the cost, estimated at $720 billion over 10 years.

That position puts him at odds with Senate Republican leaders, who said there is no need to make changes now, and President George W. Bush, who on Feb. 11 threatened to veto any effort to alter the law.

``I do feel there needs to be some changes in the Medicare drug benefit in order to make it affordable,'' Gregg, a New Hampshire Republican, said today on ABC's ``This Week'' program. ``There has to be spending restraint in that program.''

Gregg, one of nine Republicans who voted against the Medicare law in 2003, said the benefit's cost should be limited to the Congressional Budget Office's estimate of $400 billion over 10 years starting in 2004. The White House budget office last year said it would cost $511 billion starting in 2004 and last week estimated that the price over the first 10 years the law is fully in effect would be about $720 billion. Over 75 years, Greg said, the drug benefit will cost $8.6 trillion.

Senate Majority Leader Bill Frist of Tennessee and Senator Rick Santorum of Pennsylvania, both Republicans, said separately today that the Medicare benefit should go into effect as planned on Jan. 1.

`Expensive Program'

``I don't think that you're going to see any effort on the part of at least me or Republicans at this point, to try to change a program that hasn't even been implemented yet,'' Santorum, the third-ranking Republican in the Senate, said on CBS's ``Face the Nation.'' ``We knew it was an expensive program.''

Gregg's remarks reinforced similar calls for changes made by some Republican and Democratic lawmakers last week, including Alabama Republican Senator Jeff Sessions, who supported the 2003 legislation.

Gregg also said Medicare, the U.S. health insurance program for 41 million elderly and disabled people, shouldn't pay for medications to treat impotence in men, such as Pfizer Inc.'s Viagra and Eli Lilly & Co.'s Cialis.

Democrats, including Senator Kent Conrad of North Dakota, also are pushing for changes in the Medicare law. Conrad, one of 11 Democrats who voted for the drug benefit, said a $10 billion fund to entice private insurers to offer coverage to seniors should be eliminated. Medicare should also be allowed to directly negotiate with drugmakers over prices.

The ban on direct negotiation ``makes no sense at all,'' Conrad said on ``This Week.''

To contact the reporter on this story: Kristen Hallam in Washington at khallam@bloomberg.net

Last Updated: February 13, 2005 13:48 EST