Can novacaine/root canal make you sick?

Yes Many Factors: Just your anxiety or stress about the root canal can make you "sick". It is rare but possible to be allergic to "novocaine", now usually xylocaine (lidocaine). And if you received a lot of local anesthesia, the more possible. Lastly, if the tooth had a large infection, it is possible the root canal caused a systemic reaction.

Yes: People respond differently to dental proceedures and the anesthetic. The most common "shot" dentist give is Lidocaine with Epinephrine it . Occasionally some of the anesthetic is injected in to a blood vessel and the patient will feel their heart race. I have seen patients react to the topical anethetic on the q tip placed on the gum before the shot. I stock 3 types of local anesthetic.