The major risk with using compounded products for topical anesthesia remains a concern many patients have. The balance of getting sufficient anesthesia without risking absorption overdose remains the challenge with these products. Here are a few tips I think will help:
1. Ask your physician about what is in the cream and the percentages. Most topical agents for facial lasers have concentrations of lidocaine and tetracaine under 10%. If their product has higher percentages, make sure you get some explanation on their philosophy for using such higher concentrations. Also, some lasers and devices hurt more than others, and the clinic should use coentrations anticipating the expected device pain and discomfort.
2. Ask your physician about the phamracy compounding the agent and the suggested storeage/expiration date. In many communities, there are some compounding pharmacies that generally do a higher volume of business in this space, and thus their compounds are more well known in the local community. There are also national compounders that make topical creams for lasers. Often the storeage instructions and expirations dates are clear, and these products have less effectiveness if they are expired or improperly stored. Also be aware that the FDA regulations for these products are different than traditional pharmaceuticals.
3. Be aware of the surface area of your body getting the creams. In general, the front of the face represents a surface area of the body that is under 5% of total body surface area.. For this reason, the application of topicals on the face for lasers is very safe. However, if you have a lower BMI and the cream is repeatedly applied, risks can increase. Also occlusion of the product can increase its absorption and thus increase both efficacy and risk.
4. Make sure you ask your doctor about their experience performing small nerve blocks. Often times, good nerve blocks can reduce the need for exessive topical concentrations for extended periods of time.
5. Finally, be aware that the cleaner the skin, the more effectively and efficiently the topical will be absorbed. Make sure your face is washed before the topicla is applied. Some offices will clean the face with acetone or alcohol to make sure the surface is clean, optimizing the efficacy of the cream.