Novocaine is the trade name for Procaine, a local anesthetic which replaced Cocaine for medical use in 1905. The drug Procaine belongs to a chemical group called esters which can create severe side effects and allergies.
Procaine is infrequently used today. This is partly because of the side effects of ester anesthetics but mostly because it was replaced in dental and medical use by a much better compound, Lidocaine, in the 1940s. The source of Lidocaine is completely different from Procaine. However, in order to position the new medication in the market place the inventors gave it a name that people would recognize as an anesthetic with a ‘caine’ on the end.
Therein lies the confusion.
Lidocaine is neither an alkaloid nor an ester. It is a new type of pain relief which is hypoallergenic and used topically has no side effect and no actions beyond the area of application.