The effect of botulinum toxin may be potentiated by aminoglycoside antibiotics or other drugs that interfere with neuromuscular transmission e.g. tubocurarine-type muscle relaxants. Continuous concomitant use of NEURONOX with aminoglycosides or spectinomycin is contraindicated. Use of polymyxin, tetracycline, or lincomycin for patients taking NEURONOX should be done with caution.
The effect of administering different botulinum neurotoxin serotypes at the same time or within several months of each other is unknown. Excessive neuromuscular weakness may be exacerbated by administration of another botulinum toxin prior to the resolution of the effects of a previously administered botulinum toxin.