Botulinum toxin belongs to the class of medications called neuromuscular paralytic agents. It blocks the nerves that are responsible for muscle activity. For cosmetic purposes, it can be used to smooth out facial lines and wrinkles, such as those that form between the eyebrows, on the forehead, and around the eyes (crow's feet). It gives skin a smoother appearance by relaxing the muscles in the area where it was injected.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are receiving this medication, speak to your doctor. Do not stop receiving this medication without consulting your doctor.

The dose of medication required depends on the area being treated and individual circumstances.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are receiving the medication without consulting your doctor.

Botulinum toxin is available in injectable form. The injection will be given into a muscle by a qualified health care professional.

It is important to receive this medication exactly as recommended by your doctor. If you miss an appointment to receive botulinum toxin, contact your doctor as soon as possible to reschedule your appointment. It is very important to keep your appointments for treatment and follow-up.

Store this medication according to the package directions.

Each sterile vial contains 50, 100, or 200 Allergan units of vacuum-dried Clostridium botulinum toxin type A. Nonmedicinal ingredients: human serum albumin and sodium chloride. No preservatives.

Botulinum toxin should not be used by anyone who:

• is allergic to botulinum toxin or to any of the ingredients of the medication
• has an infection at the site the injection is to be given in
• has myasthenia gravis, amyotrophic lateral sclerosis, or Eaton Lambert syndrome

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• blurred or double vision
• drooping of the upper eyelid
• dry eyes
• face pain
• flu-like illness
• headache
• muscle weakness at the injection site
• nausea
• pain, tenderness or bruising, burning, swelling, or stinging at the injection site
• redness of the skin
• tightness of the skin

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abnormal heart rhythm
• burning or prickling sensation
• facial paralysis
• itchy skin
• rash

Stop taking the medication and seek immediate medical attention if any of the following occur:

• breathing problems
• difficulty swallowing
• speech problems
• symptoms of a heart attack (e.g., nausea; sweating or clammy skin; feeling of impending doom; chest tightness, pain, or pressure)
• symptoms of a severe allergic reaction (e.g., hives, difficulty breathing, swelling of the throat or mouth)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Distant toxin spread: Very rarely, this medication may spread to other parts of the body other than where it was injected, leading to muscle weakness, difficulty swallowing, pneumonia, speech difficulties, and breathing problems. Distant toxin spread can be fatal. If you develop severe difficulty swallowing, speaking, or breathing while using this medication, contact your doctor immediately.

Heart disease: Botulinum toxin has rarely been reported to cause arrhythmia and heart attack. People with heart conditions may be at increased risk of irregular heartbeat or heart attack. If you have a heart condition, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Other medical conditions: People with amyotrophic lateral sclerosis, with disorders that produce a depletion of acetylcholine, or disorders that produce peripheral neuromuscular dysfunction should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: This medication is not recommended during pregnancy. If you become pregnant while using this medication, contact your doctor immediately.

Breast-feeding: It is not known if this medication passes into breast milk. If you are a breast-feeding mother and are using this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: This medication is not recommended for children.

There may be an interaction between botulinum toxin and any of the following:

• aclidinium
• aminoglycoside antibiotics (e.g., gentamicin, neomycin, tobramycin, streptomycin)
• amoxapine
• antihistamines (e.g., brompheniramine, diphenhydramine)
• antipsychotics (e.g. clozapine, olanzapine, risperidone)
• atropine
• azelastine
• belladonna
• benztropine
• clidinium
• darifenacin
• disopyramide
• flavoxate
• glycopyrrolate
• ipratropium
• moclobemide
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• muscle relaxants (e.g. cyclobenzaprine, orphenadrine)
• oxybutynin
• quinidine
• scopolamine
• solifenacin
• tiotropium
• tolterodine
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, imipramine)
• trospium
• umeclidinium

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.