What did the inserts on your prescriptions say? There should be documents provided with them that give you a break down of medecines you MUST not take at the same time. :)
Theoretically, coadministration of drugs that are Beta-2 adrenergic agonists with other agents that can prolong the QT interval may result in additive effects, and result in ventricular arrythmias including torsade de pointes and sudden death. Generally speaking, combination of agents can often be unpredictable, depending on other coexisting risk factors.
This does not necessarily mean this will happen to you. ALWAYS consult with your doctor or pharmacist to discuss your concerns.
I also suggest that you take advantage of the interenet. Search "drug interactions" and follow the prompts for valuable information at your finger tips.