This is off of the Drug Insert for Drontal Plus by Bayer:
"The tablets may be offered to the dog by hand. Alternatively tablets may be given directly by mouth or offered in a small amount of food. Fasting is neither necessary nor recommended prior to or after treatment."
Drontal plus contains: Praziquantel, Pyrantel, Febantel.
Drontal contains just: Praziquantel, Pyrantel.
Thus the feeding recommendation should be the same for both Drontal and Drontal Plus. Sorry - I do not have just the plain Drontal insert to quote.
Hope this helps.