I thought I was going crazy, good to see (I guess) that other people have this problem too. I even found the woman who sells the pills and there was no dialogue option to talk to her about the quest. I walked to the next room and picked the lock to get to the storage room, stole the pills I needed and the dialogue options would still not change, and I still can not progress with this main quest...quite a shame as it was going so well up until this point.