Which statement regarding the comparison between ester and amide drugs is FALSE?

The statement that ester drugs can be used as injectable drugs in dentistry is not accurate. While ester local anesthetics, such as procaine, have been used historically, they are not commonly used for injections in contemporary dental practice due to their higher likelihood of causing allergic reactions and their rapid metabolism by plasma esterases. In contrast, amide local anesthetics, such as lidocaine and articaine, are more widely utilized for injectable anesthesia because they are generally safer, have a lower incidence of allergic reactions, and have a longer duration of action due to their hepatic metabolism.

Ester drugs are known to be more likely to cause allergic reactions primarily because of their metabolite, para-aminobenzoic acid (PABA), which can trigger hypersensitivity in some patients. They are biotransformed in the blood, which is characteristic of ester compounds, as their metabolism happens rapidly and in the plasma, making them less viable for longer procedures compared to amides that are metabolized more slowly in the liver. Additionally, ester drugs such as benzocaine are indeed commonly used for topical anesthesia, especially in situations where a rapid onset of action is desired for surface applications.