Some condoms designed to prevent premature ejaculation. Benzocaine largely inhibits sensitivity on the penis, and can allow for an erection to be maintained longer (in a continuous act) by delaying ejaculation. Conversely, an erection will also fade faster if stimulus is interrupted.
Benzocaine mucoadhesive patches have been used in reducing orthodontic pain.
In Poland it is included, together with menthol and zinc oxide, in the liquid powder (not to be confused with the liquid face powder) used mainly after mosquito bites. Today's ready made Pudroderm was once used there as pharmaceutical compound.
Benzocaine can come in a variety of preparations including:
Cream (ex. Lanacane - active ingredient 3% Benzocaine)
Solution (ex. Allergen)
Benzocaine is generally well-tolerated and non-toxic when applied topically as recommended.
However, there have been reports of serious, life-threatening adverse effects (e.g., seizures, coma, irregular heart beat, respiratory depression) with over-application of topical products or when applying topical products that contain high concentrations of benzocaine to the skin.
Overapplication of oral anesthetics such as benzocaine can increase the risk of pulmonary aspiration by relaxing the gag-reflex and allowing regurgitated stomach contents or oral secretions to enter the airway. Applying an oral anesthetic and consuming beverages before going to bed can be particularly hazardous.
The topical use of higher concentration (14-20%) benzocaine spray products applied to the mouth or mucous membranes has been found to be a cause of methemoglobinemia, a disorder in which the amount of oxygen carried by the blood is greatly reduced. This side effect is most common in children under 2 years of age. As a result, the FDA has stated that benzocaine products should not be used in children under 2 years of age, unless directed by and supervised by a healthcare professional. Symptoms of methemoglobinemia usually occur within minutes to hours of applying benzocaine, and can occur upon the first-time use or after additional use.
Benzocaine is commonly found, particularly in Britain, as an impurity in street cocaine and also as a bulking agent in "legal highs". Whilst giving a numbing effect similar to cocaine on users' mucous membranes, it does not actually produce the effects of cocaine. Benzocaine was used in synthesis of leteprinim. Treatment of benzocaine with hydrazine leads to aminostimil - a compound related to isoniazid.
^Eslamian L, Borzabadi-Farahani A, Edini HZ, Badiee MR, Lynch E, Mortazavi A (2013). "The analgesic effect of benzocaine mucoadhesive patches on orthodontic pain caused by elastomeric separators, a preliminary study". Acta Odontol Scand. 71 (5): 1168–73. doi:10.3109/00016357.2012.757358. PMID23301559.
^Lexicomp Online, Adult and Pediatric Lexi-Drugs Online, Hudson, Ohio: Lexi-Comp, Inc.; 2013; April 15, 2013.
^Food and Drug Administration. FDA Public Health Advisory: Life-threatening side effects with use of skin products containing numbing ingredients for cosmetic procedures. 2007 Feb 6, updated 2007 Feb 9. From FDA website
^Sidhu, S. K.; Shaw, S; Wilkinson, J. D. (1999). "A 10-year retrospective study on benzocaine allergy in the United Kingdom". American Journal of Contact Dermatitis. 10 (2): 57–61. doi:10.1016/s1046-199x(99)90000-3. PMID10357712.
^ abCetylite Industries. Cetacaine® (benzocaine 14%, tetracaine 2% and butamben 2%) spray, gel and liquid prescribing information. Pennsauken, NJ; 2006 Sept.
^Demare, Patricia; Regla, Ignacio (2012). "Synthesis of Two Local Anesthetics from Toluene: An Organic Multistep Synthesis in a Project-Oriented Laboratory Course". Journal of Chemical Education. 89: 147. doi:10.1021/ed100838a.
^Erlenmeyer, E.; Wanklyn, J. A. (1865). "Ueber das durch Einwirkung von Jodwasserstoff auf Mannit beziehungsweise auf Melampyrin (Dulcit) entstehende β Hexyljodür und einige seiner Derivate". Annalen der Chemie und Pharmacie. 135 (2): 129. doi:10.1002/jlac.18651350202.
^Ritsert, E. (1925) "Über den Werdegang des Anästhesins" (On the development of Anästhesin), Pharmazeutische Zeitung, vol. 60, pages 1006–1008. See also: Christoph Friedrich and Magdalena Klimonow, "150. Geburtstag: Eduard Ritsert und das Anaesthesin" (150th birthday: Eduard Ritsert and Anästhetsin [Benzocaine]"), Pharmazeutische Zeitung online. First published clinical study demonstrating the efficacy of benzocaine: Noorden, C. v. (1902) "Ueber para-Aminobenzoesäure-Ester als locales Anästhetikum" (On [an] ester of para-aminobenzoic acid as a local anaesthetic), Klinische Wochenschrift, vol. 39, pages 373–375.