Buffered by antibiotics, he is currently shooting for Karan Johar's "Kabhi Alvidaa Na Kehna" at Film City in the suburbs of Mumbai.
"There's nothing that can be done about it," he whispers in a barely audible voice. "A commitment is a commitment. And Karan's film has already suffered inordinate delays."
But "Kabhi Alvidaa..." is being shot in-sync sound. Wouldn't the voice quality suffer? "I am somehow managing. If the voice is not up to the mark, we will have to dub these lines later," says the superstar.
This is not the first time Bachchan is working through an illness. Two years ago, he shot tough action scenes in Los Angeles with an acute toothache for Sanjay Gupta's "Kaante".
At the peak of his first reign as a superstar in the 1970s, he had blisters on his feet while doing the "Khai ke paan benaras wala ..." song in "Don". He had to take several pain-killing injections while shooting it.
"These are things that one takes in one's stride. Can't have a film suffering just because you are not well," he says.