Supramaximal doses of botulinum toxin for refractory blepharospasm.

Abstract

To investigate the response to supramaximal doses of botulinum toxin in patients with refractory blepharospasm. Prospective, nonrandomized, open-label interventional case series. Eight consecutive patients with blepharospasm requiring injections every 2 months despite receiving 100 U of botulinum toxin per session. Increasing the dose of botulinum toxin per session above the conventional maximum. Duration of treatment effect and patients' subjective response to treatment. Supramaximal dosages were well tolerated. Seven of 8 patients had a prolonged interval between injections relative to that associated with their previous dosing regimen. Four of the patients elected to continue with the new dosage. In select patients with essential blepharospasm who are refractory to standard treatment regimens, increasing the dosage of botulinum toxin above 100 U per session may decrease the interval between injections, improve the patient's quality of life, or both.