Benzocaine is a common local anesthetic found in over-the-counter products. It temporarily numbs a specific area of the body, alleviating pain or discomfort by blocking nerve signals. Benzocaine is available in various forms, including creams, gels, sprays, ointments, and lozenges.
Understanding Benzocaine’s Duration
The numbing effect of benzocaine begins very quickly after application. For many over-the-counter formulations, onset can occur within minutes, with sensation changes in as little as 15 to 30 seconds when applied to oral mucous membranes. This rapid action makes it suitable for immediate, temporary relief.
The general duration of benzocaine’s numbing effect is short-lived. Most over-the-counter products provide pain relief that lasts approximately 5 to 20 minutes. In dental settings, a 20% benzocaine gel applied to the oral mucosa typically lasts between 5 to 10 minutes.
While some stronger formulations might offer effects up to an hour, the intensity of the numbing sensation may diminish over this period. Benzocaine is designed for temporary symptom relief and is not intended for prolonged pain management.
Influences on Benzocaine’s Working Time
Several factors can affect how long benzocaine’s numbing effect lasts.
Concentration
The concentration of benzocaine in a product plays a role, with higher concentrations (e.g., 5% to 20%) generally leading to a more noticeable and potentially longer-lasting effect. This increased concentration allows for more effective nerve signal blockage.
Application Area
The specific area of application also influences duration. Mucous membranes, like those in the mouth or throat, tend to absorb benzocaine faster than intact skin. While this can lead to a quicker onset, the effect on mucous membranes might be shorter due to factors such as saliva washing away the product.
Product Formulation
The product’s formulation (gel, spray, liquid, or lozenge) can impact its absorption rate and how well it adheres to the application site. Gels, for instance, may gradually seep into tissues, potentially extending the effect compared to sprays or solutions that might be more easily dissipated.
Individual Factors
Individual physiological differences, including a person’s metabolism, can cause variability in how quickly the body processes the medication. Using the correct amount of product as directed is important for achieving its intended effectiveness; applying too much or too little can alter the expected duration and efficacy.
Best Practices for Using Benzocaine
To achieve the intended duration and effectiveness of benzocaine, it is important to follow specific application guidelines.
Always read and adhere to the instructions provided on the product label, as usage directions can vary between different formulations and concentrations.
Cleaning and drying the affected area before applying benzocaine helps ensure optimal contact and absorption.
Apply a thin layer of the product to the target area.
Avoid using benzocaine on open wounds, broken skin, or large areas of the body, as this can increase systemic absorption and potential risks.
Do not cover treated skin areas with bandages or plastic wrap unless specifically advised by a healthcare professional, as this can also enhance absorption.
Do not exceed the recommended dosage or frequency of application.
For oral applications, avoid eating or drinking for at least one hour after use to prevent washing away the product and to maintain the numbing effect.
Benzocaine is intended for temporary relief; if symptoms persist or worsen after about seven days, or if new symptoms develop, it is advisable to consult a healthcare provider.
The FDA advises against the use of oral benzocaine products for children younger than two years, particularly for teething pain, due to the potential risk of a rare but serious blood condition called methemoglobinemia.
Always prioritize safety and seek professional medical advice if there are any concerns about using benzocaine.