Safety of OnabotulinumtoxinA with Concomitant Antithrombotic Therapy in Patients with Muscle Spasticity: A Retrospective Pooled Analysis of Randomized Double-Blind Studies

Abstract

Background OnabotulinumtoxinA is approved as a treatment across multiple indications. For the treatment of spasticity, onabotulinumtoxinA is injected directly into affected muscles. Intramuscular injections may result in local bleeding and related complications, especially in patients receiving anticoagulant therapy. Despite anticoagulants being commonly used, there is limited information in the medical literature regarding the safety of intramuscular medications in patients receiving oral anticoagulants. This retrospective analysis included pooled safety data from Allergan-sponsored studies evaluating onabotulinumtoxinA for the treatment of patients with muscle spasticity. Objective The objective of this study was to determine the risk of bleeding complications in patients with post-stroke spasticity receiving antithrombotic therapy and intramuscular onabotulinumtoxinA. Methods We conducted a retrospective analysis of pooled safety data from 16 randomized, double-blind, placebo-controlled Allergan-sponsored studies of onabotulinumtoxinA for the treatment of post-stroke upper or lower limb muscle spasticity, including adult patients with at least moderate upper or lower limb spasticity and receiving at least one dose of the study drug. Bleeding-related adverse events starting within 4 weeks of study treatment were assessed. The incidence rates of bleeding complications were compared for patients receiving classes of antithrombotic therapy vs those not receiving antithrombotic therapy and for those receiving onabotulinumtoxinA vs placebo (with or without antithrombotic therapy). Results Of 1877 patients, 1182 received antithrombotic therapy. The overall incidence of bleeding complications was < 2%. In those receiving any antithrombotic therapy, the incidence of bleeding was 1.0% vs 1.4% (no antithrombotic therapy); after onabotulinumtoxinA, it was 0.9% for those receiving antithrombotic therapy vs 1.4% (no antithrombotic therapy), and for placebo 1.2% vs 1.4%, respectively. Subgroup results were similar. Conclusions No apparent increased risk of bleeding complications was observed following administration of onabotulinum-toxinA to patients receiving antithrombotic therapy. Nonetheless, patient education and careful observation of the injection site in patients receiving antithrombotic therapy remains warranted.

Safety of Onabotulinumtoxin A in Chronic Migraine: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

“…In fact, phytocomplexes endowed with analgesic and non-benzodiazepine-like anxiolytic effects [ 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 ] deserve investigation for pain [ 125 ] as an add-on in these patients, to reduce AEs particularly in the light of the neuropsychiatric symptoms developed [ 126 , 127 , 128 ]. Furthermore, data concerned with the safety of onabotulinumtoxin A with concomitant antithrombotic therapy in patients with muscle spasticity have been provided in a retrospective, pooled analysis of randomized sponsored studies investigating onabotulinumtoxin A for the treatment of post-stroke upper or lower limb muscle spasticity [ 129 ]. The results demonstrate that the incidence of bleeding was 0.9% in patients receiving antithrombotic therapy after the treatment with onabotulinumtoxin A (with respect to 1.4% in patients not receiving antithrombotic therapy).…”

Botulinum Toxin Injection and Electromyography in Patients Receiving Anticoagulants: A Systematic Review

“…In a review consisting of five studies on performing EMG in anticoagulated patients, the authors focused on the safety of EMG practice in anticoagulated patients but not on the practice patterns of practitioners 19 . Likewise for BTX, a recent review article consisting of 16 studies focused more on the safety of Botulinum A toxin in patients with concomitant antithrombotic therapy, rather than the practice patterns of practitioners 20 . This systematic review contributes to existing literature beyond what has been published regarding safety.…”