The Prophet [SAW] said: "Whoever drinks Khamr and puts it in his belly, Allah will not accept his Salah for seven (days), if he dies during them" - Muhammad bin Adam (One of the narrators) said: "he will die a Kafir. If he was too intoxicated to offer any of the obligatory" - Ibn Adam said: "or recite Qur'an, his Salah will not be accepted for 40 days, and if he dies during them," And Ibn Adam said: "He will die a Kafir."
"I entered upon 'Abdullah bin 'Amr bin Al-'As when he was in a garden of his in At-Ta'if called Al-Waht. He was walking and holding hands with a young man of Quraish who was suspected of drinking Khamr. He said: 'I heard the Messenger of Allah [SAW] say: Whoever drinks Khamr once, his repentance will not be accepted for 40 days, then if he repents, Allah will accept his repentance. If he does it again, his repentance will not be accepted for 40 days, then if he repents, Allah will accept his repentance. If he does it again, his repentance will not be accepted for 40 days, then if he repents, Allah will accept his repentance. If he does it again (a fourth time), then it is a right upon Allah to make him drink from the mud of Khibal on the Day of Resurrection." This is the wording of 'Amr.
"'Umar, may Allah be pleased with him, banished Rabi'ah bin Umaiyah to Khaibar for drinking Khamr, and he went and joined Heraclius and became a Christian. 'Umar, may Allah be pleased with him, said: 'I will never expel any Muslim after this.'"