Following the Trump administration in the US slapping 100 per cent tariffs on branded or patented pharmaceutical products effective October 1, pharma stocks led by Sun Pharma tanked.
The Mumbai-headquartered medical manufacturer is a Sensex component. Sun Pharma was the biggest loser in the 30-pack index in Friday trade so far.
The benchmark index slid as much as 451 points to a low of 80,704.34 in the morning.
The Nifty also slumped, shedding around 131 points to a 24,759 low in early trading on Friday.
Other Sensex laggards were Asian Paints, Tech Mahindra, Infosys, Power Grid, HCL Tech, and Tata Steel.
[Story is being updated]