What are the side effects of abobotulinumtoxinA?

Some side effects of abobotulinumtoxinA are minor and do not require medical attention unless they do not go away or become more severe. These include: dry mouth; fatigue; headaches; nausea; neck pain; pain, redness, swelling, or tenderness at the injection site; sinus inflammation; sore throat; and stiff or weak muscles at or near the injection site. Other more serious side effects require immediate medical attention. These include: severe allergic reactions, such as a rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips or tongue; or hoarseness; bleeding at the injection site; difficulty swallowing or breathing; dizziness; drooping of the upper eyelid; swelling of the eyelid; facial paralysis; fainting; lack of bladder control; loss of strength; seizures; severe or persistent muscle weakness; shortness of breath; slow heartbeat; speech changes or problems; vision changes; and wheezing.