Pharmacologic class:

Topical anesthetic

Active ingredients:

Lidocaine 70 mg, tetracaine 70 mg; topical patch.

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Local dermal analgesia for superficial venous access and superficial dermatologic procedures (e.g., excision, electrodesiccation, shave biopsy of skin lesions).


Synera is a topical patch that contains a eutectic mixture of lidocaine, an amide-type local anesthetic, and tetracaine, an ester-type local anesthetic. Both of these agents block sodium ion channels required for the initiation and conduction of neuronal impulses, resulting in local anesthesia.

The Synera patch contains an integrated, oxygen-activated heating component that is intended to enhance the delivery of the local anesthetic. It begins to heat once the patch is removed from the pouch and is exposed to oxygen in the air.

Clinical trials:

Three placebo-controlled studies in adults and geriatric subjects evaluated the degree of dermal analgesia upon venipuncture following a 20-minute treatment with Synera or a placebo patch. In all three studies, less pain was reported following Synera treatment compared with placebo.

In a placebo-controlled study, 61 pediatric subjects (stratified by age group: 3-6 years and 7-17 years) received either Synera or placebo 20 minutes prior to venipuncture or IV cannulation in the antecubital fossa or dorsum of the hand. Children in the younger group reported less pain with Synera than with placebo. Pain scores in the older children treated with Synera were not statistically significantly different from pain scores in those treated with placebo.

In another study, subjects received either Synera without heating element or intact, heated Synera prior to venipuncture. Less pain was reported with the heated Synera compared with the non-heated patch. The efficacy of Synera was also evaluated in adults who received Synera or placebo for 30 minutes prior to a superficial dermatologic procedure. Less pain was reported following Synera treatment compared with placebo. This effect was also seen in children 3-6 years old; how-ever, there was no difference between treatments observed in children 7-17 years of age.

Adults and children:

<3 years: see literature. Apply to intact skin. ≥3 years: Prior to venipuncture or IV cannulation: apply for 20-30 minutes. Superficial dermatologic procedures: apply for 30 minutes prior to procedure. Remove patch if irritation or burning occurs. Do not cut patch or remove top cover (may cause thermal injury). Do not cover holes on top of patch.


Avoid simultaneous or sequential application or for longer than recommended. Severe hepatic disease or pseudocholinesterase deficiency. Avoid eyes, mucous membranes, broken or inflamed skin, trauma (e.g., scratching, rubbing, exposure to extreme temperatures). Remove before undergoing MRI (contains iron powder). Effect on intradermal live vaccines unknown. Acutely ill or debilitated. Pregnancy (Cat. B). Nursing mothers.


Toxicity potentiated by Class I antiarrhythmics (e.g., tocainide, mexiletine), other local anesthetics.

Adverse reactions:

Local reactions (e.g., erythema, blanching, edema); anaphylactoid reactions.

How supplied:

Patches—2, 10.