Mumbai, Dec. 30 -- Alkem Laboratories Ltd dropped for a fifth straight session today. The stock is quoting at Rs 5418, down 1.58% on the day as on 13:19 IST on the NSE. The benchmark NIFTY is down around 0.17% on the day, quoting at 25897.6. The Sensex is at 84563.41, down 0.16%.Alkem Laboratories Ltd has eased around 3.41% in last one month.Meanwhile, Nifty Pharma index of which Alkem Laboratories Ltd is a constituent, has eased around 2.07% in last one month and is currently quoting at 22578.3, down 0.72% on the day. The volume in the stock stood at 38116 shares today, compared to the daily average of 62815 shares in last one month. The benchmark December futures contract for the stock is quoting at Rs 5422.5, down 1.44% on the day. Alk...