You should not use this medicine if you have had an allergic reaction to lidocaine, prilocaine, or similar anesthetics such as bupivacaine, mepivacaine, or dibucaine. You should not use this medicine if you have a blood disorder called methemoglobinemia.
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
Make sure your doctor knows if you are using acetaminophen, benzocaine, chloroquine (Aralen® Phosphate), dapsone, or gentian violet. Tell your doctor if you are also using mexiletine (Mexitil®), nitrofurantoin (Furadantin®, Macrobid®), nitroglycerin (Minitran®, Nitro-Bid®), para-aminosalicylic acid (Paser®), phenobarbital, phenytoin (Dilantin®), primaquine, quinine, a sulfonamide (such as trimethoprim/sulfamethoxazole, Bactrim®), or tocainide (Tonocard®).
Make sure your doctor knows if you are pregnant or breastfeeding, or if you have liver disease or a blood disease called glucose-6-phosphate dehydrogenase (G6PD) deficiency.
The numbness may last for 30 minutes after you receive this medicine. There is an increased risk of injury to your tongue, lips, and the inside of your mouth while you are numb. To avoid injury, do not chew solid foods or foods that are too hot or cold until normal feeling has returned to the area. Do not test the feeling in your mouth by biting it or poking things in your mouth.
This medicine is applied only to your gums. It should not be used in the area near the eyes. This medicine can cause serious eye irritation.