- Randomized, Double-Blind Comparison of Acute beta1-Blockade With 50 mg Metoprolol Tartrate vs 25 mg Carvedilol in Normal Subjects. Billeh, R., Hirsh, D., Barker, C., Jorgensen, B., Jeger, R., Ramanathan, K., Tseng, C.H., Hudaihed, A., Haas, F., Jorde, U.P. Congestive heart failure (Greenwich, Conn.) (2006)