09/27/2008 at 01:00 AM EDT
Sen. Ted Kennedy, who was diagnosed with a brain tumor in May, was briefly hospitalized Friday near his Cape Cod home, the Associated Press reports.
His office attributed the need for medical attention to a change in medication, and the Senator returned home after three hours.
Authorities received a 911 call from the Kennedy compound at Hyannis Port a little after 5 p.m., Barnstable, Mass., police Sgt. Ben Baxter tells AP.
Kennedy, who had complained of feeling ill, was taken to Cape Cod Hospital in an ambulance and was "alert and responsive," said Baxter.
Kennedy, 76, is recovering from brain surgery in June after he was diagnosed with a malignant brain tumor
. The surgery, his office said at the time, would be followed by chemotherapy and radiation at Massachusetts General Hospital in Boston.
Kennedy's last public appearance was at the Democratic National Convention last month.
"It's so wonderful to be here! Nothing – nothing – is going to keep me away from this special gathering," he said smiling and waving to the delegates in Denver. "I will be there next January on the floor of the United States Senate when we begin the next great chapter of American progress."