Isakson said that since Jackson had withdrawn his nomination to be veterans affairs secretary, the committee is no longer investigating allegations about the White House doctor and problems at the White House Medical Office.
On Wednesday, White House press secretary Sarah Sanders said Jackson's record was "impeccable", and said he had passed multiple background checks, including one conducted by the Federal Bureau of Investigation.
The accusation against Navy Rear Adm. Ronny Jackson, the White House physician, was one of the more serious allegations the Senate Veterans' Affairs Committee examined as part of his confirmation process this month. John Tester, a Democrat, released a litany of allegations against Jackson, including claims that he was often drunk at work and overprescribed drugs.
"The Secret Service is unable to confirm (in fact they deny) any of the phony Democrat charges which have absolutely devastated the wonderful Jackson family".
"Of course I stayed there", Trump said on "Fox & Friends". In a tweet, the president declared the allegations against Jackson "not true".More news: Intermediate Capital Group plc (ICP) Received Average Rating of "Purchase" by Analysts
More news: Maoists gunned down by the police in Chhattisgarh
More news: Instant Analysis on Browns selecting CB Simeon Thomas
Jackson is accused of drunkenly banging on the hotel door of a female subordinate, being involved in an alcohol-related vehicle crash, and improperly dispensing prescription medications. "Very dishonest and sick!" he tweeted.
It's unclear if Jackson will remain on staff at the White House medical unit or if he'll depart the administration.
The White House continually defended Jackson as his nomination cratered on Capitol Hill this week.
Tester is facing a reelection campaign in November in a state Trump won in 2016. The president announced the move before the White House had a chance to do the sort of thorough vetting typically performed on Cabinet-level nominees.
CNN had reported allegations that Jackson drunkenly banged on the hotel room door of a female employee and that Secret Service personnel intervened out of concern that he would wake Obama.