A recent study in Anesthesia Progress has shown that phentolamine can reverse the effects of lidocaine 30–55% faster than your body can metabolize it naturally, and there are no attributable side effects.
The study by Paul A. Moore, Elliot V. Hersh, et al. reports that phentolamine mesylate, which has been available in the United States since the 1950s, may help you recover feeling faster by counteracting the effect of epinephrine.
Epinephrine delays the body's absorption of lidocaine (one of the most widely used local anesthetics in dentist offices around the country). With this delay removed, the body can absorb and break down the lidocaine faster.
Recovery occurs approximately twice as fast with the use of phentolamine than without, and it works to return sensation to both lips/cheeks and tongue.
There were no serious adverse events reported and no subjects discontinued the study due to adverse events.
To find out more about the society, visit American Dental Society of Anesthesiology.