European Journal of Cardiovascular Medicine

Cosmetic surgical procedures have witnessed a significant rise in popularity due to increasing aesthetic awareness and advancements in minimally invasive techniques. Procedures such as Botox injections, dermal fillers, micro-needling, and laser resurfacing are commonly performed to enhance facial aesthetics, reduce wrinkles, and improve skin texture. However, many of these procedures involve varying degrees of pain and discomfort, necessitating the use of effective topical anesthetic agents to enhance patient comfort and procedural efficiency [1,2].

Topical anesthetics are widely used in dermatology and cosmetic medicine due to their non-invasive nature, ease of application, and ability to provide localized pain relief. These agents function by blocking sodium channels in nerve membranes, preventing pain signal transmission to the brain [3]. Various formulations, including lidocaine, prilocaine, tetracaine, and benzocaine, are available, each with distinct pharmacokinetics, onset times, duration of action, and potential adverse effects [4].

Lidocaine, a widely used amide-type local anesthetic, has a rapid onset of action and a moderate duration, making it a preferred choice for short procedures such as Botox and dermal filler injections [5]. Prilocaine, often combined with

lidocaine in eutectic mixtures, enhances penetration and extends anesthetic effects, making it ideal for laser treatments and micro-needling [6]. Tetracaine, an ester-based anesthetic, is known for its longer duration of action, providing extended numbness but requiring a longer application time to achieve peak effectiveness [7]. In contrast, benzocaine, a rapidly acting ester anesthetic, is frequently used in over-the-counter formulations, but it has been associated with a higher risk of allergic reactions and methemoglobinemia in certain cases [8].

Despite their widespread use, comparative data on the efficacy of different topical anesthetics in cosmetic procedures remain limited. Variations in onset time, depth of anesthesia, and side effect profiles necessitate a comprehensive evaluation to determine the most suitable agent for each procedure. The selection of an anesthetic agent should be based on procedure duration, pain intensity, and patient-specific factors such as skin sensitivity and allergy history [9,10].

This study aims to compare the efficacy of lidocaine, prilocaine, tetracaine, and benzocaine in reducing procedural discomfort in cosmetic interventions. By assessing pain perception, duration of anesthesia, and side effects, this research seeks to provide evidence-based recommendations for optimizing pain management strategies in aesthetic medicine.

A prospective, randomized, double-blind study was conducted at a dermatology and cosmetic surgery clinic from January 2024 to December 2024. The study protocol was approved by the institutional ethics committee, and all participants provided informed consent.

Participants

A total of 120 patients undergoing minor cosmetic procedures were recruited based on the following inclusion and exclusion criteria:

Inclusion Criteria:

• Patients aged 18–65 years.
• Undergoing minor cosmetic procedures such as Botox, dermal fillers, or laser treatments.
• No history of hypersensitivity to topical anesthetics.

Exclusion Criteria:

• Presence of open wounds, infections, or active dermatological conditions at the application site.
• Pregnant or lactating women.
• Patients with a history of severe allergic reactions to local anesthetics.

Intervention

Patients were randomly assigned into four groups (30 each), receiving different topical anesthetics:

1. Lidocaine 5% cream
2. Prilocaine 5% cream
3. Tetracaine 4% gel
4. Benzocaine 20% gel

Each anesthetic was applied in a uniform quantity (2 g) over a 5 cm² area for 30 minutes before the procedure.

Outcome Measures

1. Pain Perception: Pain intensity was recorded using the Visual Analog Scale (VAS) (0 = no pain, 10 = worst pain).
2. Onset and Duration: Time from application to peak effect and duration of numbness were documented.
3. Adverse Effects: Skin reactions, erythema, pruritus, and allergic reactions were recorded.

Statistical Analysis

The data were analyzed using SPSS version 25.0. Mean pain scores were compared using ANOVA, and post hoc analysis was conducted for pairwise comparisons. The significance level was set at p < 0.05.

The comparison of pain perception among the different topical anesthetic agents revealed significant variations in efficacy. Tetracaine exhibited the most effective pain reduction, with an average Visual Analog Scale (VAS) score of 1.6, indicating minimal discomfort during cosmetic procedures. This was followed by Lidocaine and Prilocaine, which had comparable VAS scores of 2.8 and 2.9, respectively. Benzocaine had the highest pain perception among all agents, with a VAS score of 3.5, making it the least effective in reducing procedural discomfort (Table 1).

Table 1: Comparison of Pain Scores Across Different Anesthetics

The onset of action varied across different anesthetics. Lidocaine and Prilocaine had the fastest onset times, averaging 10 minutes, making them suitable for short-duration procedures requiring immediate pain relief. Tetracaine exhibited a slower onset, averaging 15 minutes, but provided the longest duration of anesthesia at 45 minutes. Benzocaine, although having a moderate onset time of 12 minutes, had the shortest duration of action, lasting only 25 minutes, which may limit its effectiveness in prolonged procedures (Table 2).

Table 2: Onset and Duration of Action of Anesthetic Agents

In terms of adverse effects, Benzocaine was associated with the highest incidence of side effects, with 26.6% of patients experiencing allergic reactions, 23.3% reporting erythema, and 20% experiencing pruritus. This was significantly higher compared to the other anesthetics. Lidocaine and Prilocaine had relatively lower adverse reaction rates, with only 16.6% and 13.3% of patients, respectively, experiencing erythema, and 3.3% and 6.6% reporting allergic reactions. Tetracaine had the lowest overall adverse effects, with only 10% of patients reporting mild erythema and 3.3% experiencing allergic reactions. These findings suggest that Tetracaine not only provided superior pain relief and prolonged anesthesia but also had a favorable safety profile (Table 3).

Table 3: Adverse Effects Among Participants

The patient satisfaction levels with different topical anesthetics were assessed using a 5-point Likert scale, ranging from 1 (Very Dissatisfied) to 5 (Very Satisfied). Tetracaine had the highest patient satisfaction score, with a mean rating of 4.7, indicating excellent patient acceptance. Lidocaine and Prilocaine followed closely with mean scores of 4.3 and 4.2, respectively, showing high levels of satisfaction. In contrast, Benzocaine received the lowest satisfaction rating, with a mean score of 3.5, largely due to higher pain perception and increased incidence of side effects (Table 4).

Table 4: Patient Satisfaction Scores for Different Topical Anesthetic Agents

Topical anesthetic agents play a crucial role in pain management during cosmetic surgical procedures, ensuring patient comfort and procedural success. The findings of this study provide a comprehensive comparison of four widely used topical anesthetics—Lidocaine, Prilocaine, Tetracaine, and Benzocaine—highlighting their efficacy in terms of pain perception, onset and duration of anesthesia, adverse effects, and patient satisfaction. These results have important implications for optimizing anesthetic selection based on procedure type, patient preference, and safety considerations.

The effectiveness of a topical anesthetic is primarily determined by its ability to reduce pain perception during cosmetic procedures. Our findings indicate that Tetracaine was the most effective agent, providing the lowest VAS pain scores (1.6 ± 0.7), significantly lower than Lidocaine (2.8 ± 0.9), Prilocaine (2.9 ± 1.0), and Benzocaine (3.5 ± 1.2). These results are consistent with previous studies reporting Tetracaine’s superior analgesic effect due to its higher lipid solubility and deeper tissue penetration [1,2].

Lidocaine and Prilocaine exhibited comparable efficacy, with slightly higher pain scores than Tetracaine but significantly better pain control than Benzocaine. Lidocaine’s rapid onset and moderate duration make it a preferred choice for quick procedures like Botox injections or dermal fillers [3,4]. Prilocaine, often used in combination with Lidocaine, enhances penetration and reduces discomfort in laser treatments and micro-needling [5]. However, its vasodilatory properties may result in a slightly longer onset compared to Lidocaine [6].

Benzocaine, despite being commonly used in over-the-counter numbing agents, was the least effective in pain relief, showing the highest pain scores among all anesthetics. This aligns with prior reports suggesting Benzocaine’s limited penetration depth and shorter duration of action make it less effective for deep dermal analgesia [7].

The study demonstrated significant differences in onset time and duration of anesthesia among the four agents. Lidocaine and Prilocaine had the fastest onset (10 minutes), followed by Benzocaine (12 minutes), while Tetracaine exhibited a slower onset (15 minutes) but the longest duration (45 minutes). These findings align with previous pharmacokinetic studies indicating Lidocaine’s rapid onset due to its high membrane permeability, making it a popular choice for time-sensitive procedures [8,9].

The prolonged anesthetic effect of Tetracaine is attributed to its stronger binding affinity for sodium channels, which prolongs nerve blockade compared to Lidocaine and Prilocaine [10]. This makes Tetracaine more suitable for long-duration procedures such as laser resurfacing, chemical peels, and micro-needling [11]. Conversely, Benzocaine had the shortest duration (25 minutes), making it less effective for extended procedures.

While topical anesthetics are generally safe, their adverse effect profile varies depending on their chemical properties, absorption, and patient susceptibility. Our study found that Benzocaine was associated with the highest incidence of adverse reactions, including erythema (23.3%), pruritus (20%), and allergic reactions (26.6%). This aligns with prior research indicating Benzocaine’s high allergenic potential and risk of methemoglobinemia, particularly in susceptible individuals [12,13].

Lidocaine and Prilocaine had moderate adverse effect rates, with pruritus occurring in 10% of patients and mild erythema in 16.6% and 13.3%, respectively. These agents have a well-established safety profile but should be used cautiously in patients with a history of lidocaine sensitivity [14]. Tetracaine exhibited the lowest incidence of adverse effects, supporting its superior safety and tolerability profile when used appropriately [15].

Patient satisfaction plays a pivotal role in the selection of anesthetic agents in cosmetic dermatology. The study’s Likert scale assessment revealed that Tetracaine had the highest satisfaction score (4.7/5), followed by Lidocaine (4.3/5) and Prilocaine (4.2/5), whereas Benzocaine had the lowest satisfaction (3.5/5). These findings reinforce Tetracaine’s preference due to its potent analgesia, extended duration, and lower incidence of side effects [16,17].

However, for short-duration procedures, such as Botox injections or lip fillers, Lidocaine and Prilocaine remain viable choices due to their fast onset [18]. While Tetracaine is superior for prolonged procedures like laser therapy and micro-needling, it may not be ideal in settings where rapid onset is a priority [19].

Clinical Recommendations and Future Directions

The findings from this study suggest that the choice of topical anesthetic should be guided by procedure duration, patient pain threshold, and potential for adverse effects. Based on the results, we recommend:

• For short procedures (<30 min): Lidocaine (5%) or Prilocaine (5%) due to their rapid onset and good pain control.
• For long procedures (>30 min): Tetracaine (4%) due to its superior duration and pain relief.
• For patients with a history of allergic reactions: Avoid Benzocaine due to its high allergenic potential.

Further research should focus on comparing combination anesthetic formulations (e.g., Lidocaine-Prilocaine eutectic mixtures) to determine whether synergistic effects enhance pain relief while minimizing adverse reactions [20]. Additionally, nano-formulated anesthetics and microneedle-assisted delivery systems are promising advancements that could optimize topical anesthesia in dermatological and cosmetic procedures.

This study provides compelling evidence that Tetracaine is the most effective topical anesthetic for cosmetic procedures, offering superior pain relief, prolonged anesthesia, and high patient satisfaction with minimal side effects. Lidocaine and Prilocaine remain effective alternatives for shorter procedures, while Benzocaine is less favorable due to higher pain perception and adverse reactions. These findings support procedure-specific anesthetic selection to maximize patient comfort and safety in aesthetic medicine.

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