BMA Concise Guide to Medicine & Drugs

Botulinum Toxin

Brand names Azzalure, Botox, Dysport, NeuroBloc, Vistabel, Xeomin

Used in the following combined preparations None


Drug group Muscle relaxant

Overdose danger rating High

Dependence rating Low

Prescription needed Yes

Available as generic No


Botulinum toxin is a neurotoxin (nerve poison) produced naturally by the bacterium Clostridium botulinum. The toxin causes botulism, a rare but serious form of food poisoning.

Research has found that there are several slightly different components in the toxin. Two are used medically: botulinum A toxin and botulinum B toxin. They are used therapeutically to treat conditions in which there are painful muscle spasms, for example spastic foot deformity, blepharospasm (spasm of the eyelids, causing them almost to close), hemifacial spasm, and spasmodic torticollis (spasms of the neck muscles, causing the head to jerk). Toxin A is also used to treat very resistant and distressing cases of hyperhidrosis (excessive sweating). The effects produced by the toxins may last for 2–3 months, until new nerve endings have formed.

Botulinum toxin is used cosmetically to remove facial wrinkles by paralysing the muscles under the skin.


This drug is given only under medical supervision and is not for self-administration.

How taken/used Injection.

Frequency and timing of doses Every 2–3 months, depending on response.

Adult dosage range Dose depends on the particular condition being treated. Individual injections may range from 1.25 units to 50 units. The number of injection sites depends on the size and number of the muscles to be paralysed. Specialist judgement is necessary.

Onset of effect Within 3 days to 2 weeks.

Duration of action 2–3 months.

Diet advice None.

Storage Not applicable as the drug is not normally kept in the home.

Missed dose Attend for treatment at the next possible time.

Stopping the drug If having botulinum toxin for medical reasons, discuss with your doctor whether you should stop receiving the drug. Cosmetic use of the drug can be stopped safely at any time.

Exceeding the dose When used for medical reasons, overdose is unlikely since treatment is carefully monitored. If the drug was injected into your face for cosmetic reasons, the effects of an overdose will develop gradually over several days; you should be especially alert for any weakness in your neck or swallowing difficulty and, if they occur, you should contact your doctor immediately.


Some of the adverse effects depend on the site of injection. Common ones include reduced blinking and dry eyes, painful swallowing, and pain or weakness at the injection site. Misplaced injections may paralyse unintended muscle groups. All paralyses are likely to be long lasting. Rarely, botulinum toxin may cause glaucoma or painful eyes, neck weakness, head tremor, or hypersensitivity reactions. Consult your doctor if any of the above adverse effects occur. Occasionally, the drug may cause difficulty swallowing (rather than just pain on swallowing); if so, call your doctor immediately.




Be sure to tell your doctor if:

· You have any difficulty in swallowing.

· You are taking an anticoagulant drug or have a bleeding disorder.

· You are allergic to botulinum toxin.

· You are taking other medicines.

Pregnancy Not prescribed.

Breast-feeding Not prescribed.

Infants and children Reduced dose necessary.

Over 60 No special problems.

Driving and hazardous work Do not drive until you know how botulinum toxin affects you; the drug may impair ability.

Alcohol No known problems.


To maintain the desired effects, the drug may have to be administered at regular intervals.