'Buffy' star Nicholas Brendon in a Malibu rehab, taking sober acting class

"Buffy the Vampire Slayer" star Nicholas Brendon has checked into rehab.

Brendon reportedly blames alcohol and a sleeping pill for his March 17 arrest, when he got into a fight with cops and got himself seriously tased and booked.

"I was in treatment in 2005 and unfortunately I had a relapse. In the back of my mind, I always knew I had a problem but it became clear to me when I got arrested," he says, according to Radaronline.