What a waste of time.
In time it took you to type this and wait for a response, you could have
gone to a local retail pharmacy and had your prescription professionally
filled and questions about your prescription answered.
So if time is money, and I know it is to me, you are already losing.
But thats just the opinion of this independent retail pharmacist.

Ilotysin (R) is simply a form of erythromycin.  You should talk to the
prescriber, and see if an alternative brand or generic name can be
substituted.  Erythromycin is readily and inexpensively available in the US.