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OBJECTIVE: To determine if patients reporting flu-like symptoms (FLS) after botulinum toxin (BoNT) injections are less susceptible to this reaction after incobotulinum toxin.

BACKGROUND: Approximately 10% of patients injected with BoNT in our clinic complain of FLS, primarily malaise, myalgias and rhinorrhea, beginning a few days to one week after injection and lasting one week or less. A review by Baizabal-Carvallo et al. (Toxicon, 2011, 58:1-7) found rates of FLS between 1.7 and 20% in patients after various preparations of botulinum toxin A, and a subsequent study showed increased cytokines in patients with FLS (Neurotoxicity Research, 2013, 24:298-306). Besides the neurotoxin itself, most BoNT preparations contain associated complexing proteins (NAPs), most of which are hemagglutinins. It is thought that NAPs induce the release of inflammatory cytokines, which may cause the FLS. Incobotulinum toxin is a botulinum toxin A preparation where the active peptide is separated from the NAPs (hemagglutinins and non-hemagglutinins) through a series of steps yielding the active neurotoxin with molecular weight of 150 kDa, without accessory proteins.

DESIGN/METHODS: Consecutive patients who reported FLS consistently occurring after previous BoNT injections (> two prior treatment sessions, average 21 sessions, patients reporting FLS after “most sessions”) were offered further injections with incobotulinum toxin at similar doses.

RESULTS: Six patients were identified as having had FLS and given injections with incobotulinum toxin. Three were cervical dystonia patients, and one each with blepharospasm, hemi-facial spasm and tics secondary to Tourette’s. All reported a satisfactory clinical response similar to their previous injections. One patient had only rhinorrhea, the others had malaise and myalgias. None of the patients experienced flu- like symptoms after incobotulinum toxin injections (16 treatment sessions).

CONCLUSIONS: Initial results from this open-label, unblinded series suggests patients who have consistently experienced FLS after BoNT injections are much less likely to do so after injection with incobotulinum toxin.


Neurology | Neurosciences