i have been on metoprolol succ ER 50mg for quite some years as well as Losartan 100mg but my BP is still high so my cardiologist switched my Losartan to Valsartan 320 mg. I just took the valsartan for the first time and it made me dizzy, light headed, my heart started racing and now i feel so tired and sleepy. I have not taken the metoprolol today because I didnt; know the interaction between the two meds. BP was 160/90 but now its 144/87. Maybe my valsartan dosage is too high? Afraid to take the metoprolol now.