I take Venlafaxine (300mg), Atenolol (50mg), and Mobic (15mg) daily. I have been taking the Venlafaxine and Atenolol for months, and the Mobic for 2 weeks. I notice no interaction problems, but dugs.com says that Venlafaxine and Mobic can cause upper GI bleeding and Atenol and Mobic cause increased potassium levels. I take Atenolol primarily as a headache deterrent. I used to get headaches almost daily, but none since I started taking it. The Mobic is for my back (a pinched nerve) and so far Mobic has worked great for that.