Okay I need some help from all you people. I have been on Zyrtc a...

Okay I need some help from all you people. I have been on Zyrtc and Singulair for about 10+ years. This past Monday was my last pill for both. Tues and Wed did pretty well. Thursday and Friday not so much. I can handle the sneezing and watery eyes what I can not handle is the ITCHING!!! Driving me crazy. That started about 3 this afternoon. My doctor does not want me to take any antihistamine. How long is the withdrawal take from these meds? Any suggestions or advice would be greatly appreciated