My boys got their DHPP and Lyme together and both had terrible reactions. I ended up giving the one some children's Benadryl, and that seemed to be a great remedy. I don't know if I would call the reaction "sleepiness", but my didn't do anything, including eating. There was no vomiting or diarrhea, but they didn't feel well at all.
In talking with my vet afterward, they have now marked the charts that they don't receive the DHPP anymore ... they are 7 and 9 years old and the previous years of vaccines have more than safeguarded them in his mind. They'll only get Lyme and Rabies anymore.
Hope this helps and that Murphy is feeling better soon!
