How does it work?

Botox injection contains botulinum toxin type A, which is a toxin produced by the bacteria Clostridium botulinum.

Botulinum toxin type A is a bacterial toxin that prevents nerves from functioning normally (a neurotoxin). It prevents nerves from releasing a chemical called acetylcholine, which is essential for the nerves to communicate with muscle cells. This toxin therefore prevents muscles from receiving nerve stimulation.

Preventing nerve stimulation of muscles causes the muscles to become paralysed. Botulinum toxin type A causes muscle paralysis until such time as the nerve develops new endings to communicate with the muscles. It is useful for treating conditions where excessive nerve stimulation to muscles is causing abnormal muscle functioning, contractions or spasms. It is injected into the affected muscle for this purpose.

The toxin is also useful for preventing excessive sweating, as it prevents nerve signals from reaching the sweat glands in the same manner. For this purpose the toxin is injected into the skin in the armpit.

The toxin also blocks the release of chemicals that are involved in sending nerve messages associated with the production of pain. The injection is given into the muscles around the back of the neck, forehead and temples to prevent headaches in people who suffer from chronic migraine.

What is it used for?

• Uncontrolled blinking or continuous closure of the eyelid in adults (blepharospasm).
• Muscle spasm affecting one side of the face in adults (hemifacial spasm).
• Spasmodic rotation of the head to one side in adults (spasmodic torticollis/idiopathic cervical dystonia).
• Wrist and hand disability in adults due to spasm of the muscle in the upper arm as a result of a stroke.
• Foot deformity due to spasm of leg muscles in children with cerebral palsy aged two years and over (dynamic equinus foot deformity).
• Severe excessive sweating from the armpits in adults (hyperhidrosis), when this can't be controlled by antiperspirants.
• Preventing headaches in adults who suffer from chronic migraines (people who have headaches on at least 15 days per month of which at least 8 days are with migraine).

Warning!

• If you or someone you are caring for develops any swallowing, speech or breathing problems after having treatment with this medicine, you should consult your doctor immediately.
• If your symptoms improve after having these injections, make sure you resume your normal activities gradually. Try not to do too much too quickly as you may risk injury.
• Too frequent or excessive use of this medicine can cause the body to produce antibodies against the medicine, which could make it less effective.
• This medicine contains albumin, which is obtained from human blood. There is a small risk of viral infection associated with the use of this medicine, because the risk of transmitting infectious agents cannot be eliminated fully when using human blood products.

Use with caution in

• People with inflammation in the area to be injected.
• People at risk of bleeding after an injection into a muscle, for example due to blood clotting disorders such as haemophilia, or treatment with anticoagulant medicines.
• People with excessive weakness or wasting in the muscle to be injected.
• People with a history of swallowing difficulties (dysphagia) or liquid accidentally going into the lungs (aspiration).
• People with chronic breathing problems.
• Diseases or conditions affecting the nervous system (neurological conditions) for example motor neuropathy or amyotrophic lateral sclerosis, in which there is progressive degeneration of the nerves that activate the muscles.
• Other muscle problems or chronic disease affecting the muscles, for example Eaton Lambert syndrome or myasthenia gravis.
• History of seizures, eg epilepsy.
• Disease involving the heart and blood vessels (cardiovascular disease).
• People who have recently had surgery or are due to have surgery in the near future.
• People at risk of closed angle glaucoma (applicable only to those being treated for blepharospasm).
• People who have had previous eye surgery (applicable only to those being treated for blepharospasm).

Not to be used in

• People with an infection at the proposed injection site.
• People who have previously had an allergic reaction to botulinum toxin type A injections.

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• The safety of this medicine for use during pregnancy has not been established. It should not be used during pregnancy unless considered essential by your doctor. Seek medical advice from your doctor.
• It is not known if this medicine passes into breast milk. It is not recommended for the treatment of women who are breastfeeding. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

General side effects:

• Pain, soreness or bruising at the injection site.
• Misplaced injections may paralyse nearby muscles and excessive doses may paralyse muscles that are not near the injection site.
• Fever.
• Flu-like symptoms.
• Difficulty or pain when swallowing (dysphagia).
• Food or liquid accidentally going into the lungs (aspiration).
• Irregular heart beats (arrhythmias) or heart attack (rarely).
• Seizures.
• Allergic reactions, such as rash, itching, swelling, breathing difficulties or anaphylaxis.

Specific side effects when treating blepharospasm/hemifacial spasm:

• The soft eyelid tissues bruise easily. Your doctor will try to reduce this by applying gentle pressure after giving the injection.
• Drooping of the upper eyelid.
• Sensitivity of the eyes to light.
• Dry or watery eyes.
• Wide open eyes.
• Inflammation of the front of the eye (cornea).
• Facial swelling or paralysis.
• Dizziness.
• Turning inwards or outwards of the eyelid.
• Visual disturbances such as blurred or double vision.
• Fatigue.
• Rash.
• Eyelid swelling.
• Ulceration of the front of the eye (cornea).

Specific side effects when treating cervical dystonia:

• Swallowing difficulties.
• Muscle weakness.
• Dizziness.
• Headache.
• Sleepiness.
• Increased rigidity, stiffness or soreness of muscles.
• Numbness.
• Feeling sick.
• Dry mouth.
• General feeling of being unwell.
• Drooping of the upper eyelid.
• Voice changes.

Specific side effects when treating cerebral palsy:

• Viral or ear infections.
• Sleepiness.
• Tingling or pins and needles sensations.
• Muscle pain or weakness.
• Urinary incontinence.
• General feeling of being unwell.
• Rash.
• Problems with walking.

Specific side effects when treating stroke patients:

• Increased rigidity of muscles.
• Bruising and bleeding under the skin causing red patches (ecchymosis or purpura).
• Arm or hand pain.
• Muscle weakness.
• Headache.
• Numbness.
• Pins and needles sensations.
• Spinning sensation.
• Feeling sick.
• General feeling of being unwell.
• Lack of coordination.
• Difficulty sleeping (insomnia).
• Depression.
• Rash or itching.
• Aching joints.

Specific side effects when treating excessive sweating:

• Increased sweating from areas not treated.
• Hot flushes.
• Headache.
• Feeling sick.
• Muscle pain or weakness.
• Arm weakness.
• Itching.

Specific side effects when treating chronic migraine

• Worsening of headache/migraine in some people in the first month of treatment, improving with repeated treatment.
• Facial paralysis.
• Neck pain.
• Muscle pain, tightness, stiffness, weakness or spasm.
• Eyelid drooping.
• Rash or itching.
• Eyelid swelling.
• Jaw pain.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

Tell your doctor if you are taking any other medicines, including herbal medicines and those bought without a prescription, before you have treatment with this medicine, so they can check that the combination is safe.

Tell your doctor if you have recently had any other botulinum toxin injections, because if this injection is given too close to a previous injection it could cause excessive muscle weakness.

The muscle paralysing effect of botulinum toxin type A may be increased by the following medicines:

• antibiotics such as polymixins, tetracyclines or lincomycin
• aminoglycoside antibiotics, eg neomycin, gentamicin, tobramycin
• muscle relaxants, particularly those used in anaesthesia
• spectinomycin.

Other medicines containing the same active ingredient

These products are not interchangeable.