Dharma Iolite 20% Benzocaine Topical Anesthetic Gel, 1.12 oz · Pina Colada · Standard

• Gel — The form a review pairs with the injection site, applied before infiltration anaesthesia. A review reports that benzocaine reduces pre-injection pain in the alveolar mucosa and works on the tongue, but is hardly effective on the palatal mucous membrane, which is thick and firm with densely packed nerves.
• Spray — Effectively blocks a wide surface. Prolonged exposure increases the risk of absorption into the circulatory system.
• Anesthetic Ointments — A review pairs ointments with solutions for patients with aphthous ulcers. Benzocaine is poorly soluble in water, which hinders cardiovascular absorption and leaves residues on the applied surface for relatively prolonged periods.

Form: a review lists sprays, solutions, gels and ointments, developed with different indicated uses to make clinical use easier.

Concentration: benzocaine concentrations used range from 6 to 20 percent.

Allergy: benzocaine is an ester-type agent composed of p-aminobenzoic acid that can induce allergic reactions, while allergic reactions are infrequent with amide-type anaesthetics. A review lists temporary altered sense of taste and allergy as the common adverse effects of topical anaesthetics.

Benzocaine is an active ingredient in several types of over-the-counter oral health care drug products, including oral anaesthetic and analgesic products marketed for the temporary relief of pain due to minor irritation, soreness or injury of the mouth and throat. The FDA notes those products are marketed in a variety of dosage forms, including gels, sprays, ointments, solutions and lozenges.

In a letter dated 21 May 2018 the FDA asked firms to relabel or discontinue the distribution and sale of certain of those products, based on evidence that they pose a serious and potentially fatal risk of methemoglobinemia to infants, children and adults. The FDA describes methemoglobinemia as a potentially serious condition where the amount of oxygen carried through the blood stream is greatly reduced. Its symptoms, in the FDA’s words, can include pale, gray, or blue colored skin, headache, light-headedness, shortness of breath, fatigue, and rapid heart rate. The FDA adds that benzocaine-induced methemoglobinemia may occur after a single exposure, and in people who have previously been exposed to benzocaine without incident.

The same letter asks for a methemoglobinemia warning on products for adults and children two years and older, in these words: use of this product may cause methemoglobinemia, a serious condition that must be treated promptly because it reduces the amount of oxygen carried in blood, and this can occur even if you have used this product before. It states that over-the-counter oral health care products containing benzocaine are not to be used to treat teething pain or in infants and children under 2 years of age in any circumstances. The FDA estimates that more than 400 cases of benzocaine-associated methemoglobinemia occurring in the United States have been reported to its adverse event reporting system and published in the medical literature since 1971.