title: Long-term botulinum toxin efficacy, safety, and immunogenicity.
abstract: To determine the long-term efficacy of botulinum toxin (BTX) treatments, we analyzed longitudinal follow-up data on 45 patients (32 women; mean age, 68.8 years) currently followed in the Baylor College of Medicine Movement Disorders Clinic, who have received BTX treatments continuously for at least 12 years (mean 15.8 +/- 1.5 years). Their mean response rating after the last injection, based one a previously described scale 0-to-4 scale (0 = no effect; 4 = marked improvement) was 3.7 +/- 0.6 and the mean total duration of response was 15.4 +/- 3.4 weeks. Although the latency and total duration of the response to treatment have not changed over time, the peak duration of response (P < 0.005) and dose per visit (P < 0.0001) have increased since the initial visit. Furthermore, global rating (P < 0.02) and peak effect (P < 0.05) have improved. In total, 20 adverse events occurred in 16 of 45 (35.6%) patients after their initial visit and 11 adverse events in 10 of 45 (22.2%) patients at their most recent injection visit. Antibody (Ab) testing was carried out in 22 patients due to nonresponsiveness; blocking Abs were confirmed by the mouse protection assay in 4 of 22 (18%) patients. Of the Ab-negative patients, 16 resumed responsiveness after dose adjustments and 2 persisted as nonrespondents. Except for 1 patient, the 4 Ab-positive and the 2 clinical nonresponders are being treated with BTX-B. This longest reported follow-up of BTX injections confirms the long-term efficacy and safety of this treatment.
authors.affiliation: Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Nicte I
authors.initials: NI
authors.lastname: Mejia
authors.forename: Kevin Dat
authors.initials: KD
authors.lastname: Vuong
authors.forename: Joseph
authors.initials: J
authors.lastname: Jankovic
mesh_terms: D000368:Aged; D000906:Antibodies / Q000276:immunology*; D001763:Blepharoptosis / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D003680:Deglutition Disorders / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology; D004334:Drug Administration Schedule; D004421:Dystonia / Q000188:drug therapy* / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D019569:Hemifacial Spasm / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology; D009334:Neck Muscles / Q000503:physiopathology; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D000906:Antibodies; D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A