Botulinum Toxin Type A and B (Botox, Dysport, Xeomin, and Myobloc) Injections

This guide from Children's Hospital of Philadelphia (CHOP) explains how botulinum toxin injections can help children with tight muscles, spasms, or drooling.

Important information:

There are two types of botulinum toxin commercially available in the United States:

  • Type A: Botox®, Dysport®, and Xeomin®

  • Type B: Myobloc®

Why does my child need botulinum toxin injections?

Botulinum toxin can be recommended for children who:

  • Have spastic/tight muscles that cause pain or make movement difficult

  • Struggle with hygiene or daily care due to muscle tightness

  • Have excessive drooling

It is used along with more conservative measures, such as physical or occupational therapy, braces, or oral medications. Unlike oral medications, these injections target specific muscles, so side effects like sleepiness or weakness are less common.

What are the goals of this treatment?

The goals of the botulinum toxin injections will be discussed during your child's appointment. Your child's goal may be functional improvement, such as improved use of their hands or walking more easily. These injections can also make daily care easier, reduce pain, and, when used for drooling, lower saliva and help keep your child from choking.

Will the injections be done during our clinic appointment?

Your healthcare team will discuss if injections should be done in clinic or with sedation. This decision is based on your child's age, comfort level, the injection site, and how many injections are needed. Sedation or anesthesia may be recommended if a higher number of injections are required or if your child has difficulty staying still. If sedation is needed, the procedure will take place in the sedation or anesthesia area; if not, it will be done in the outpatient clinic.

How are the injections performed?

1. Muscle injections:

  • Injection sites are chosen during one appointment and then confirmed on the day of the procedure.

  • Numbing cream is applied about 30-60 minutes before, and the cold spray is used just before the injection to reduce discomfort.

  • Sedation (medicine to help your child relax), if needed, is given by IV or by mouth. With sedation, your child may not have a clear memory of the event. This means they may have less fear of returning for repeat injections. Your child's pain will be also controlled with medicine during the procedure.

  • Injections are done with a very small needle. Larger muscle groups may need more than one injection. A nerve stimulator helps provider find the right spot to inject into the muscle.

  • The procedure usually takes 5-20 minutes. Afterward, your child will be observed until sedation wears off, then you can go home and return to normal activities.

2. Injection to the salivary glands:

  • No numbing cream is needed because these injections are just under the skin and less painful.

  • The skin is cleaned, and ultrasound is used to locate the salivary glands.

  • The procedure usually takes 5-10 minutes.

  • Sedation or anesthesia may be needed if your child has trouble staying still. Your team will work with you to decide if your child needs sedation or anesthesia.

How long does the botulinum toxin effect last?

The effects of botulinum toxin usually last about 3-4 months. During this time, therapies such as physical and occupational therapy may be more effective, helping your child make progress that can continue even after the medicine wears off. Injections may also be given before or after surgery to improve comfort, range of motion and function, or to see how your child responds to therapy. When used for drooling, injections into the salivary glands also last about 3-4 months. To keep the medicine effective, injections are typically spaced about 6 months apart. If they are given too frequently, the body can sometimes build resistance to the medicine, making it less effective.

Repeat injections may be appropriate when stepwise improvement is anticipated. Botulinum toxin injections tend to mimic the effects of surgical interventions because botulinum toxin temporarily causes a decrease in the tightness of muscles and improved ability to stretch these muscles. Injections are sometimes used to relieve discomfort, improve function, or increase range of motion prior to surgery. It can also be administered in coordination with or following surgery to further enhance range of motion and function. Additionally, it may allow the team to see how your child responds to therapy.

When injected into the salivary glands, botulinum toxin also lasts for 3-4 months.

There is potential for antibody formation against the botulinum toxin, which limits its effectiveness, with repeat injections because the immune system identifies the botulinum toxin as a foreign substance. Antibody formation is usually seen in cases where injections are given sooner than every 3 months. CHOP usually recommends botulinum toxin injections every six months. Occasionally, injections may be recommended more frequently during times that your child is growing rapidly.

What are the side effects of botulinum toxin?

  • Pain, tenderness, redness, or bruising at the injection site

  • Rarely, allergic reactions

When injected into muscles (for spasticity or muscle tightness):

  • Short‑term muscle weakness or reduced function (often begins within 3 weeks, improves in 1–2 weeks)

When injected into salivary glands (for drooling):

  • Temporary difficulty swallowing

  • Weakness of the voice

  • Neck muscle weakness

These side effects usually appear within 1–2 weeks after treatment and often improve on their own within 3–4 weeks.

Will my child need extra care after the botulinum toxin injection?

Yes, follow-up care is an important part of treatment.

  • Check-ups: Your healthcare provider will monitor physical examinations before and after the injections to make sure the treatment is working well.

  • Follow-up visit: A return appointment is usually needed about 3-4 weeks after the injection.

  • Extra therapy (sometimes): In some cases, the care team may recommend serial casting. This means a physical therapist places a cast on the affected arm or leg to gently stretch tight muscles. The case is changed regularly, and progress is checked each week. This process usually lasts 3-5 weeks.

Most children do not need special care beyond these steps, but follow-up visits and therapy help ensure the best results.

Warnings:

Severe effects of this drug may affect parts of the body away from where it was injected. Signs can happen from hours to weeks after the injection. Swallowing and breathing problems can be deadly. The risk is greatest in children with certain muscle problems (spasticity) but can happen to all people. Swallowing problems may last for several months. Call your child's doctor right away if your child has blurred eyesight or sees double, change in voice, drooping eyelids, or loss of strength or weakness all over the body. Call your child's doctor right away if your child cannot control the bladder or has trouble breathing, speaking, or swallowing.

If you would like to learn more about this medicine and other ways to manage spasticity, visit cpfamilynetwork.org.

Contact the Center for Rehabilitation 215-590-7439 with any questions or concerns.

 

Reviewed December 2025 by Christopher Phillips, PharmD.