i have been sick with the upper respiratory thing going
welcome to the 'Ask a Doctor' service.
Benzonatate does not interact with the rest of the drugs you're using.
Z-pak may interact with sertraline and increase the QT interval (it's an ECG parameter) which may predispose to serious arrhythmias. In most cases no adverse effect is expected but there is some potential for complications. If you want to stay on the safe side then either sertraline will have to be stopped for a few days or z-pak would have to be substituted with another antibiotic.
Keep in mind that only your doctor should take such decisions though - do not try anything yourself.
I hope I've answered your question. Please let me know if you need further assistance.