Orajel is the brand name for topical benzocaine. According to Drugs.com, Orajel is a topical medication that provides relief against pain caused by cold sores, baby teething, canker sores and toothaches. Orajel acts quickly to relieve those symptoms by numbing the surface where it's applied. It can also be used to numb an area of the mouth before a medical or surgical procedure.
When someone applies too much numbing medication, a possibility exists of the medication entering into the bloodstream. If the benzocaine from Orajel enters into the bloodstream in a significant amount, it can be life-threatening. Signs of overdose include an irregular heartbeat, seizure, coma or respiratory failure. As with any medication, only use the recommended amount to prevent dangerous consequences.
Because Orajel so effectively numbs the mouth, the person loses feeling in that area of their mouth for awhile. During that time, remember that having sensation can protect one against injury. Biting a numb area of the mouth is common, and someone who is not careful can regain feeling after Orajel--only to find that he now has more pain from bite injuries. Other dangers include burns and cuts, because the injuries from those mechanisms are not noticeable until Orajel has worn off.
Any form of benzocaine, including Orajel, can cause methemoglobinemia. Methemoglobinemia is a condition in which a person has a greater than normal amount of methemoglobin in the blood. Methemoglobin is a form of hemoglobin that can't bind oxygen. When the level of that type of hemoglobin is high, tissues in the body don't receive enough oxygen and can become damaged. Symptoms include shortness of breath, headaches, dizziness and loss of consciousness.