Yes. This is what you do. Burst and burst again. And you would also want to Insta-Kill whatever caster is DOTing you after the first. Mob casters have cooldowns too. If you are not fast enough to kill the caster after the first DOT is laid down then you deserve to die. If it is a Red Named that cannot be Insta-Killed then find something to hide behind. Laugh if you will. There is a little thing called "If they cannot see you they cannot DOT you." Works every time.