The word "indefatigable" seems to have been invented to describe Amitabh Bachchan, who is currently shooting for Karan Johar's Kabhi Alvidaa Na Kehna in Film City, buffered by a generous dose of antibiotics.

For the last two days, Bachchan has been suffering from viral fever, but continues to shoot.

"There's nothing that can be done about it," he whispers in a barely audible voice. "A commitment is a commitment; Karan's film has already suffered inordinate delays."

But Kabhi Alvidaa is being shot in sync sound. Wouldn't the voice quality suffer? "I'm managing somehow. If the voice isn't up to the mark, we'll have to dub these lines later," says the superstar.

This isn't the first time Bachchan is working through an illness — two years ago, he shot tough action sequences for Sanjay Gupta's Kaante in Los Angeles despite an acute toothache.

And at the peak of his first reign as superstar in the '70s, he had blisters on his feet while dancing to Khai ke paan Benaras wala, in Don, and was administered painkiller shots after every take.

"These are things that one takes in one's stride," whispers Bachchan. "Can't have a film suffering just because you aren't well."