Senator Edward Kennedy, seen with his wife Victoria Reggie at the Democrat convention in August, was alert and responsive when he was taken to hospital on Friday. (Ron Edmonds/Associated Press)

Senator Edward Kennedy, who has brain cancer, spent three hours in hospital Friday evening after a change in his medications made him feel ill.

The Massachusetts senator was taken by ambulance to Cape Cod Hospital, near his vacation home in Hyannis Port, at about 5 p.m. ET. His office confirmed he was home by 8 and blamed the bout of illness on his medication.

Kennedy, 76, was "alert and responsive" on the trip to the hospital, Barnstable police Sgt. Ben Baxter said.

Senator John Kerry, a fellow Democrat, had said earlier in the evening that Kennedy was hoping to be home in time for Friday night's presidential debate between Republican John McCain and Democrat Barack Obama.

Kennedy had a seizure in May. He underwent surgery in June for a malignant brain tumour and underwent six weeks of chemotherapy and radiation treatment.

Kennedy has made several public appearances since.

On Tuesday, he received a visit from Chilean President Michelle Bachelet at his home, his first public appearance since he gave a surprise speech in late August at the Democratic National Convention.

Bachelet presented the senator with her country's highest civilian award — the Order to the Merit of Chile — in recognition of his opposition to the country's 1973 government overthrow and his work to cut off military aid to the late dictator Augusto Pinochet.

At the meeting, the senator stumbled momentarily as he tried to walk on the thick grass, but he quickly regained his balance.

With files from the Associated Press