Introduction
pain
COMPLICATIONS
After the discovery of the blocking effect of botulinum toxin on acetylcholine release and neuromuscular transmissionHowever, the use of botulinum toxin is not without problemLidocaine, being a vasodilator, might have extra clinical advantages beyond pain reduction as well. Some surgeons and dermatologists suggest that the incorporation of lidocaine might enhance the efficacy or longevity of the botulinum toxin effectDespite the abovementioned points, no studies have assessed the effect of the incorporation of isolated lidocaine into botulinum toxin on the intensity of botulinum pain or complications. Due to the importance of this subject, and in light of the abovementioned shortcomings in the literature, and since there was no study on the incorporation of lidocaine without any additives such as epinephrine or sodium bicarbonate, we tested whether the addition of isolated lidocaine can reduce the pain of BTX-A. Also, we investigated whether or not the addition of lidocaine without adrenaline may cause more complications. For this purpose, a very large-scale randomized clinical trial was conducted. The null hypotheses were the lack of any effect of lidocaine and the brands of botulinum A toxin (as well as participants’ sex and age) on the injection pain or 2-week post-injection complications.