Benzocaine CAS 94-09-7

Overview:
Benzocaine is a local anesthetic commonly used as a topical pain reliever or in cough drops. It is the active ingredient in many over-the-counter anesthetic ointments such as products for oral ulcers. It is also combined with antipyrine to form A/B otic drops to relieve ear pain and remove earwax.
Mechanism of action:
Pain is caused by the stimulation of free nerve endings. When the nerve endings are stimulated, sodium enters the neuron, causing depolarization of the nerve and subsequent initiation of an action potential. The action potential is propagated down the nerve toward the central nervous system, which interprets this as pain. Benzocaine acts to inhibit the voltage-dependent sodium channels (VDSCs) on the nerve membrane, stopping the propagation of the action potential.

Benzocaine is used as a key ingredient in numerous pharmaceuticals:Over the counter throat lozenges such as Cepacol.Some glycerol-based ear medications for use in removing excess wax as well as relieving ear conditions such as otitis media and swimmers ear.Some previous diet products such as Ayds.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.
Uses:
Benzocaine is indicated to treat a variety of pain-related conditions. It may be used for:
(1) Local anesthesia of oral and pharyngeal mucous membranes (sore throat, cold sores, canker sores, toothache, sore gums, denture irritation).
(2) Otic Pain (earache).
(3) Surgical or procedural local anesthesia