... 225 Effexor and 50 mg of Pristiq. No problems. Yesterday down to 75mgs of Effexor, 50 mgs. of Pristiq. Symptoms developed was an indescribable, constant headache. I don't mean a headache where you can take a couple Tylenol and it goes away! CONSTANT! Also add chills where I was in bed at 8pm covered in 2 blankets. Help! Any suggestions are really appreciated!!!