Botulinum toxin manufacturers recommend avoiding anticoagulants during therapy. Researchers recently conducted a clinical trial to evaluate the risk.
Botulinum toxin (BT), also known as Botox®, is a neurotoxin that is commonly used for cosmetic and muscle relaxation therapies. Once injected into muscle tissue, BT quickly inactivates surrounding nerves causing muscle paralysis which reduces muscle tension. Although BT is recognized as a safe FDA-approved therapy, all BT producing pharmaceuticals warn clinicians and patients not to take BT therapy with an oral anticoagulant medication due to the risk of haematoma (blood swelling in tissue). While alternative anticoagulants provide a lower risk of haematoma, such as heparin, they carry additional side-effects and health risks.
In a study published in the Journal of Neural Transmission, researchers sought to investigate the claims and determine if anticoagulant medication increases haematoma frequency during therapy with botulinum toxin. In a retrospective study, 32 patients (16 male, 16 female) were assessed that received BT therapy for either cervical dystonia, blephoraspasm, hemi-facial spasm, or post-stroke spasticity while taking anti-coagulants.
Researchers matched all individuals in the anticoagulant group (AG) to identical candidates, except for gender, in a control group that did not use oral anticoagulants. Clinicians performed a total of 328 BT treatment cycles encompassing 20,900 injections within the AG. Contrary to the warnings, the researchers found no significant difference in overall haematoma frequency between AG and the control group, suggesting that anticoagulant medication during BT therapy does not increase the risk of haematoma. When researchers assessed haematoma frequency in both groups based on clinical need, they found no significant difference for patients with blephoraspasm, hemifacial spasm, cervical dystonia, or post-stroke spasticity. If patients did show signs of haematoma when taking BT, the researchers found it to be mild with no need for emergency medical attention. In fact, researchers found the control group to have more than double the number of BT related side-effects than anticoagulation group for blephorospasm patients which include ptosis (droopy eyelids), xerophthalmia (dry eyes), and diplopia (double vision).
BT therapy is commonly used for cosmetic and clinical purposes to smooth skin features and relax muscle tension. All BT pharmaceutical manufacturers recommend not to take anticoagulants during BT therapy, however, researchers found no increased risk of haematoma or other side-effects if used correctly. Although anticoagulants are are not a risk-free medication, this study highlights their safe use during boutlinum toxin therapy and justifies their continued use over riskier alternative anticoagulants.
Written by Aaron Kwong, MSc
Reference: C., S., M., E., P., T. & D., D. Botulinum toxin therapy in patients with oral anticoagulation: Hematoma frequency vs. Other side effects. J. Neural Transm. 120, 1154 (2013).