BLT: Triple Anesthetic Gel
- is a triple anesthetic gel consisting of 20% benzocaine, 6% lidocaine, and 4% tetracaine. It is formulated in dimethyl sulfoxide and pluronic lecithin organogel, which increases its absorption through the skin.
- It is usually applied to INTACT skin 10 to 30 minutes before surgery.
- Because it contains ester anesthetics, its use is contraindicated for patients allergic to p-aminobenzoic acid, hair dyes, and sulfonides.
- an oil-in-water emulsion of 2.5% lidocaine and 2.5% prilocaine.
- It should be used on INTACT skin. An occlusive dressing increases its penetration.
- It must be left on for 0.5 to 2 hours, depending on location and depth of penetration.
- Its use must be avoided near the eyes, since sodium hydroxide is a component of the cream to allow for proper penetration.
- EMLA cream has been shown to be safe and efficacious in geriatric patients (65 years or older), but its use is controversial in neonates less than 3 months of age.
- It is similar to TAC in effectiveness.
- Transient blanching and erythema appear at the site of application due to peripheral vasoconstriction.
- Contact dermatitis is occasionally reported secondary to the prilocaine.
- A very rare methemoglobinemia can develop in patients less than 1 year of age who take medications that exacerbate the methemoglobinemia or who have a congenital methemoglobinemia or a glucose 6-PO4 dehydrogenase deficiency.
- Cost is approximately $11 per 5 gm tube and occlusive dressing.
- Recommended Dose/Area/Time use for EMLA
|Pt Age/ Wgt||Max Dose||Max Area||Max Applied Time|
|0-3 months or less than 5 kg||1 gm||10 sq cm||1 hr|
|3-12 mo AND more than 5 kg||2 gm||20 sq cm||4 hr|
|1-6 yr AND more than 10 kg||10 gm||100 sq cm||4 hr|
|7-12 yr AND more than 20 kg||20 gm||200 sq cm||4 hr|
- composed of 0.5% tetracaine, 1:2000 epinephrine, and 4% lidocaine.
- When used for laceration repair--a shred of LET-soaked cotton or LET mixed with methylcellulose is placed directly in the wound prior to cleansing and repair. The solution or gel can be held in place with an occlusive dressing, tape, or bandage.
- The wound edges blanch when numb, usually after 20 minutes (15 - 30 min). Anesthesia lasts an average of 21 minutes after removal.
- LET has been found to be just as efficacious as TAC with no severe side effects.
- LET cost per application is approximately $3.00 compared to $35.00 for TAC
- LMX-4 (formerly ELA-max4) or LMX-5 (formerly ELA-max5) contains 4% or 5% liposomal lidocaine, respectively.
- The cream is usually applied for 15 to 40 minutes to intact skin with no occlusion necessary.
- The rapid absorption also results in a rapid dissipation of the drug, with diminishing anesthesia approximately 40-60 minutes after application.
- A transient erythema may occur, but no serious adverse side effects have been seen.
- To prevent toxic systemic levels, it has been recommended that LMX be applied to an area less than 100 cm2 in children weighing less than 20 kg.
- Its effectiveness is similar to that of EMLA.
- LMX-4 can be purchased over the counter. Cost is similar, $6-7 per 1- to 2-gm application [approx $30 per 0.54 oz tube]
- It can be used before superficial and medium-depth peels without affecting the results of the peel.
- developed as a local anesthetic peel (Zars Pharma).
- This cream dries on exposure to air and becomes a flexible membrane that is easily peeled off. This eases the delivery of the anesthetic to contoured regions of body.
- It has been shown to provide a highly effective local anesthesia. It should be applied 20-30 minutes prior to procedures such as dermal filler injections or facial laser ablation, and for 60 minutes prior to procedures such as laser treatment of leg veins and tattoo removal.
- It could be used for minor surgery as well.
- Tetracaine and lidocaine mixed 7%/7% in a self-contained patch have been studied for venipuncture.
- It is designed to look like a child's bandage and is recommended for children aged 3 years and older.
- It contains a heating element that, when activated, enhances absorption, allowing for rapid anesthesia and some degree of vasodilation.
- Cost is approximately $12 per patch.
- Was one of the first topical anesthetic creams to be developed. Initially it was composed of 0.5% tetracaine, 1:2000 epinephrine, and 11.8% cocaine.
- Later the tetracaine was increased to 1% and the cocaine decreased to 4%. It was found that the effectiveness remained the same.
- It should be applied 30 minutes before the procedure.
- Its effectiveness is comparable to that of lidocaine infiltration when used properly.
- The effectiveness of most anesthetic creams is compared with that of TAC.
- Inadvertent mucosal application or overdose can result in significant cocaine absorption, leading to serious adverse effects such as seizures and cardiac arrest.
- TAC is also very expensive at about $350 per 35-gm tube.
- is a 4% lidocaine gel.
- It is usually applied 30 to 60 minutes before the procedure with occlusion.
- Erythema, blanching, and edema at the site appear to be mild and transient.
- Allergic contact reactions to this ester group of anesthetics are common.
- Effective anesthesia with topicaine can be obtained after 30 minutes.