Meds interaction

I've been prescribed Celexa and am on Metaprolol. The PDR says to ask your Dr. before taking these together. What's the possible interaction? Should I double check w/ my Dr. even though he knew what else I was taking?

[NTB]

the metoprolol is broken down in the liver, by an enzyme. But the Celexa inhibits that enzyme. So you can end up with too much of the metoprolol in your system. You can thereby have heart rate or blood pressure too low, or worse.

it seems that reducing the metoprolol can be an option, then increasing it gradually as long as no symptoms occur.

http://www.drugs.com/drug-interactions/celexa_d04332_metoprolol_d00134.html