For Need for a Cure, you must find Kor'ghan in Orgrimmar and get the Venomtail Antidote. Then bring the antidote to Rhinag near the northwestern border of Durotar.
<name>... your timing is perfect. I just hope I can compliment your haste as well.
I was careless while fighting a few of the venomtails nearby, and one of them stung me deeply. I can feel its poison weakening me even as we speak. At this rate, I got maybe an hour left to live. But I'll need your help if I'm to do so...
Kor'ghan in Orgrimmar knows how to make the antidote. Find him... and hurry, <name>. I won't be able to last much longer. He should be in the Cleft of Shadow.
I'm almost glad I can't return to Sen'jin as I am now. My weakness and stupidity would surely be mocked.
<name>, you've saved my life. Thank you.
Please take this; I hope it can at least help you in your travels, if not bring you some coin. From what you say, I won't be usin' it anytime soon. Kor'ghan is gonna march me through more of his rituals until I prove myself. More killin' boars, more gatherin' scorpid tails... <sigh>
You will be allowed to choose one of the following:
You will be given 45 minutes to complete this quest once accepted. When you speak with Kor'ghan in Orgrimmar, in the Cleft of Shadows, you will be able to receive the  quest, which you will need to complete to receive the Venomtail Antidote, which is required to complete this quest.