Dr Yoelin: What conversion ratios do you use for switching among the BTXA products?
Dr Gold: I was an investigator in the US Food and Drug Administration clinical trials for incoBTXA and aboBTXA and have always used the ratios of 1:1 for incoBTXA:onaBTXA and 2.5:1 for aboBTXA:onaBTXA that were used to determine dosing for aboBTXA and incoBTXA in the clinical trials.
The 1:1 ratio for incoBTXA:onaBTXA is supported by the results of a multicenter, randomized, blinded clinical trial in which I participated.16 In this 4-month trial, we compared the 2 neuromodulators for treating glabellar frown lines. We used a 20-U dose of both products and found they had similar efficacy at 1 month, which was the primary end point, and at subsequent monthly follow-up visits.
Dr Kaufman: I use a conversion ratio of between 2:1 and 3:1 for aboBTXA:onaBTXA and 1.5:1 for incoBTXA:onaBTXA.
Dr Aguilera: My conversion ratios are the same as Dr Kaufman’s.
Dr Maas: I use a conversion ratio of 3:1 for aboBTXA:onaBTXA and 1.2:1 or 1.25:1 for incoBTXA:onaBTXA. I think it is important to emphasize that although the use of these conversion ratios results in a higher dose of incoBTXA or aboBTXA than onaBTXA, the difference in total dose does not mean that incoBTXA or aboBTXA is weaker or less effective than onaBTXA.