a simple and sensitive extraction-spectrophotometric method for rapid and accurate determination of benzocaine in pure and dosage forms was developed. benzocaine was effectively extracted as a 1:1 ion pair complex with dicyclohexyl-18-crown-6 and calmagite in acidic media into chloroform, followed by spectrophotometric determination at 486 nm. molar absorptivity of the ternary complex at this w...

Hille (1977. Journal of General Physiology. 69:497-515) first proposed a modulated receptor hypothesis (MRH) to explain the action of benzocaine in voltage-gated Na+ channels. Using the MRH as a framework, we examined benzocaine binding in batrachotoxin (BTX)-modified Na+ channels under voltage-clamp conditions using either step or ramp command signals. We found that benzocaine binding is stron...

Benzocaine is a topical anesthetic frequently used in healthcare facilities and in over-the-counter medications in concentrations up to 20%. Benzocaine may induce methemoglobinemia, a condition that impairs the blood’s ability to carry oxygen. The optimal management of exposure to benzocaine remains unclear because serious toxicity is uncommon and may not be dose-related. In 2000, it was estima...

We have studied the effect of local anesthetics QX 572, which is permanently charged, and benzocaine, which is neutral, on batrachotoxin-activated sodium channels in mouse neuroblastoma N18 cells. The dose-response curves for each drug suggest that QX 752 and benzocaine each act on a single class of binding sites. The dissociation constants are 3.15 X 10(-5) M for QX 572 and 2.65 X 10(-4) M for...

BACKGROUND The authors evaluated the efficacy and tolerability of 10 percent and 20 percent benzocaine gels compared with those of a vehicle (placebo) gel for the temporary relief of toothache pain. They also assessed the compliance with the label dose administration directions on the part of participants with toothache pain. METHODS Under double-masked conditions, 576 participants self-appli...

A simple and sensitive extraction-spectrophotometric method for rapid and accurate determination of benzocaine in pure and dosage forms was developed. Benzocaine was effectively extracted as a 1:1 ion pair complex with dicyclohexyl18-crown-6 and calmagite in acidic media into chloroform, followed by spectrophotometric determination at 486 nm. Molar absorptivity of the ternary complex at this wa...

UNLABELLED We investigated the mechanism of benzocaine (permanently uncharged) and QX314 (permanently charged) inhibition of lysophosphatidic acid (LPA) signaling. To determine their site of action, we studied effects of these drugs, alone and in combination, on LPA-induced Ca2+-dependent Cl currents (I(Cl(Ca))) in Xenopus oocytes. After 10 min exposure to benzocaine, QX314 (10(-6)-10(-2) M), o...

BACKGROUND Methemoglobinemia (MHb) is characterized by abnormal levels of oxidized hemoglobin that cannot bind and transport oxygen. When induced by benzocaine anesthetic spray and other chemicals, it can result in cyanosis and life-threatening complications. METHODS From 818 439 adverse event reports received by the US Food and Drug Administration from November 1997 through March 2002, we ex...

We studied the effects of the local anesthetics, procaine and benzocaine, on the action potential and force of canine ventricular muscle and Purkinje fibers. In ventricular muscle, procaine often shifted the plateau to a more positive value and increased the force of contraction, whereas benzocaine shortened the action potential and decreased contractile force. In Purkinje fibers, both local an...

BACKGROUND Contact allergy to local anaesthetics is relatively common. Patch testing with benzocaine in the European baseline series is recommended for diagnosis, even though a caine mix has been previously suggested to be superior. OBJECTIVES To assess the frequency and patterns of contact allergy to local anaesthetics by using a caine mix (benzocaine, tetracaine, and cinchocaine) in the bas...