Generality
Botulinum toxin is a neurotoxin produced by beating Clostridium botulinum .
Although known primarily for its use in the field of aesthetic medicine, botulinum toxin can be used as a drug also in other areas of medicine, in order to counteract various disorders and diseases.
Basically, there are two types of botulinum toxin: type A and type B. While in Aesthetic Medicine mostly botulinum toxin type A is used, in other fields of medicine it is also possible to use type B.
However, regardless of type A or B, botulinum toxin acts at the level of nerve endings that innervate the musculature, interfering with the release of a particular neurotransmitter: acetylcholine . The administration of botulinum toxin occurs only by parenteral injection, by injection .
Curiosity
In common parlance, botulinum toxin is often referred to - even if improperly - as "botulinum".
Examples of Medicinal Specialties containing Botulinum Toxin
- Botox®
- Dysport®
- NeuroBloc®
- Xeomin®
Please note
Even the botulinum toxin used in aesthetic medicine to smooth wrinkles is part of the composition of real drugs (Azzalure®, Bocouture®, Vistabex®) which must be administered only by medical personnel. However, in this article, when we talk about botulinum toxin as a drug we want to refer exclusively to the neurotoxin used in medicine for the treatment of disorders and diseases and not to use for purely aesthetic purposes.
Therapeutic indications
When is the use of Botulinum Toxin indicated?
As mentioned, in the field of non-aesthetic medicine both botulinum toxin type A and botulinum toxin type B are used.
Botulinum toxin type A
Botulinum toxin type A is indicated for:
- Treating persistent muscle spasms in the hands, wrists, legs and ankles of stroke patients ;
- Treat persistent muscle spasms of the eyelids ( blepharospasm );
- Treat persistent muscle spasms in the arms, neck and shoulders (stiff neck);
- Reduce the symptoms of chronic migraine in adult patients who experience headaches for 15 days or more a month, of which at least 8 with migraine (this use, however, is done only if the patient does not respond to the classic treatments for migraine);
- Check the condition of overactive bladder with urinary incontinence when the patient does not respond to conventional treatments;
- Treat urinary incontinence caused by bladder disorders resulting from bone marrow injury or multiple sclerosis .
Furthermore, botulinum toxin type A is used in children over 2 years of age due to the symptomatic treatment of spasticity of the lower limbs caused by dynamic equinus foot deformity. In children and adolescents over the age of 12, however, type A neurotoxin is used in the treatment of axillary hyperhidrosis .
Botulinum toxin type B
Botulinum toxin type B is used for the treatment of torticollis ( cervical dystonia ).
Please note
The use of botulinum toxin type B has been approved only and exclusively for the treatment of torticollis . In no case should it be used for the treatment of other disorders or diseases.
Warnings
Warnings and Precautions for the use of Botulinum Toxin
Before undergoing botulinum toxin treatment, it is advisable to inform your doctor if:
- You are suffering from haemophilia or other disorders that promote bleeding ;
- You are being treated with anticoagulant drugs ;
- You suffer from marked muscle weakness or loss of muscle tone at the site where the drug should be injected;
- One is suffering from peripheral neuromuscular dysfunction ;
- You suffer from severe muscular and / or neuromuscular pathologies ;
- It is difficult to swallow ;
- You suffer from lung disorders and / or respiratory problems ;
- One must undergo surgery or have undergone surgical treatments in the past that may have altered the structure of the muscle at which the botulinum toxin should be injected.
Furthermore, it would be advisable to inform the doctor even if you suffer or if you are at risk of developing closed-angle glaucoma ; if you have suffered seizures ; if you are suffering from cardiovascular diseases .
In any case, before starting a botulinum toxin therapy, it is always a good idea to inform your doctor of your health conditions, by informing them of the possible presence of disorders and diseases of any kind.
Please note
The administration of botulinum toxin can cause side effects that can alter the ability to drive and / or use machines . Therefore, during treatment with the aforementioned neurotoxin, these activities should be avoided.
Pharmacological Interactions
Interactions of Botulinum Toxin with Other Drugs
Because of the drug interactions that could occur, before the administration of botulinum toxin it is necessary to inform the doctor if you are taking, or if you have recently been taken:
- Antibiotic drugs (could increase the effect of botulinum toxin);
- Muscle relaxant drugs or anticholinesterase drugs (they too could increase the effect of botulinum toxin);
- Other drugs containing botulinum toxin (for example, those used in aesthetic medicine, or other medicinal products for the treatment of diseases and disorders referred to in the "Indications" chapter);
- Antiplatelet drugs ;
- Anticoagulant drugs .
In any case, before starting treatment with botulinum toxin, it is a good idea to inform your doctor if you are taking - or have recently taken - any type of medication, including non-prescription medicines (SOP), the OTC drugs, herbal and herbal products and homeopathic products.
Side effects
Side effects caused by the assumption of Botulinum Toxin
Botulinum toxin can cause numerous types of side effects, although not all patients manifest them, or manifest them in the same way. In fact, each individual responds in a subjective manner to the administration of the drug. The main undesirable effects that could occur after botulinum toxin injections are listed below. In this regard, it should be pointed out that these effects may vary depending on the site in which the drug is injected. However, this distinction will not be highlighted below, but some of the possible undesirable effects grouped according to the organ, tissue, system or apparatus concerned will be listed.
Please note
Side effects do not occur immediately but generally after a few days . Furthermore, they can be transient, or last for days or even months.
Nervous system disorders
After the injection of botulinum toxin may occur:
- Drowsiness;
- Paresthesia or hypoesthesia;
- Hypertonia;
- Paresis and facial paresis;
- Lack of motor coordination;
- Headache;
- Memory disorders (amnesia);
- Dizziness.
Psychiatric disorders
Botulinum toxin injection could cause depression and insomnia.
Musculoskeletal disorders
Treatment with botulinum toxin may favor the appearance of:
- Myasthenia;
- Myalgia;
- arthralgia;
- Bursitis;
- Muscle weakness;
- Muscle stiffness;
- Soreness.
Disorders of the digestive system
Treatment with botulinum toxin may cause:
- Nausea and vomit;
- Dysphagia;
- Dyspepsia;
- Abdominal pain;
- Diarrhea or constipation.
Respiratory disorders
After injecting the botulinum toxin, the following side effects on the respiratory system may arise:
- Dyspnoea;
- Dysphonia;
- Depression or respiratory failure.
Eye disorders
The administration of botulinum toxin can cause various disorders of the eyes which, in most cases, occur when the neurotoxin is used for the treatment of blepharospasm. However, among these we find:
- Changes in vision;
- Ulcerative keratitis;
- Corneal perforation;
- Ectropion;
- Alteration of the corneal epithelium;
- Eyelid ptosis (this side effect can also occur when botulinum toxin is used to treat migraine).
Skin and subcutaneous tissue disorders
Following the injection of botulinum toxin, the following may appear:
- Skin eruptions;
- Bruising;
- Itch;
- Dermatitis;
- Alopecia.
Disorders of the kidneys and urinary tract
The administration of botulinum toxin could cause:
- Urinary incontinence;
- Urinary tract infections;
- Dysuria;
- pollakiuria;
- leukocyturia;
- hematuria;
- Bacteriuria.
These side effects occur especially when the neurotoxin covered by the article is used in the treatment of overactive bladder or in the treatment of urinary incontinence due to dysfunctions of the bladder detrusor muscle.
Cardiovascular disorders
After the administration of botulinum toxin-based drugs, the following could occur:
- Orthostatic hypotension;
- arrhythmias;
- Myocardial infarction.
Other side effects
Other possible side effects induced by the administration of botulinum toxin consist of:
- Allergic reactions in sensitive individuals;
- Non-axillary hyperhidrosis (when neurotoxin is used in the treatment of axillary hyperhidrosis);
- Pain and / or bleeding at the injection site;
- Flu-like symptoms;
- Malaise, fever and asthenia;
- Peripheral edema;
- fatigue;
- Dry mouth;
- Anorexia;
- Hearing loss and tinnitus.
For more information about the side effects that may occur following the injection of botulinum toxin in specific districts (for example, eyelids, bladder, neck, etc.), we recommend reading the illustrative leaflet of the medicinal product to be used ; at the same time it is advisable to ask for clarifications regarding the doctor directly.
Overdose
The symptoms induced by an overdose of botulinum toxin are not evident immediately after the injection, but occur later. Among these, we find:
- Breathing difficulties;
- Generalized weakness;
- Drooping eyelid;
- Double vision;
- Difficulty speaking;
- Paralysis of the respiratory musculature and difficulty in swallowing which can, in turn, lead to the appearance of pneumonia.
If one or more of the aforementioned symptoms occur, it is necessary to contact the medical help immediately or, if possible, go to the emergency room in person.
Action mechanism
How does Botulinum Toxin work?
Botulinum toxin carries out what can be defined as a muscle relaxant action. To do this, it acts at the level of the nerve endings that innervate the muscles, blocking the neuromuscular transmission made by the acetylcholine and which would lead to their contraction.
More precisely, the botulinum toxin acts at the level of the presynaptic cholinergic nerve endings , hindering and blocking the release of acetylcholine (ACh) . The exact mechanism of action can be simplified and divided into the following phases:
- Immediately after the injection, the botulinum toxin binds with high affinity to specific receptors present on the external surface of the presynaptic termination .
- After that, the toxin is transferred into the cellulanervosa by receptor-mediated endocytosis .
- The toxin is then released into the cytoplasm where - through the interaction with the SNAP25 protein responsible for the release of acetylcholine by the motor neuron - it induces a progressive inhibition of ACh release .
The effect induced by botulinum toxin is localized to the site where it is injected, however, cases have been reported in which the administration of the neurotoxin has had repercussions also at a systemic level.
Method of use and Posology
How to take Botulinum Toxin
Botulinum toxin is administered by injection directly into the site where muscle relaxation is desired. Clearly, such an operation must be carried out only and exclusively by specialized medical personnel .
The botulinum toxin dosage varies according to the type of disorder to be treated and must be established by the doctor. Furthermore, the dose of drug administered may vary during treatment - consisting of multiple injection cycles - depending on the patient's response to drug administration. In this regard, it should be remembered that the injections must be carried out at well-defined intervals of time that can vary, indicatively, from 6-12 weeks up to 3 months.
In any case, for more detailed information it is advisable to refer to the package insert of the medicinal product that must be used, as well as, to clarify any doubt, it is good to ask the doctor who will make the injections.
Pregnancy and breastfeeding
Can Botulinum Toxin be Assumed in Pregnancy and During Lactation?
Botulinum toxin should not be used in pregnant women, unless the doctor considers it absolutely necessary. Furthermore, the use of the neurotoxin in question is not even recommended in breastfeeding mothers .
Therefore, if the need arises to undertake a botulinum toxin treatment, pregnant women and nursing mothers must inform the doctor of their condition.
Contraindications
When Botulinum Toxin Should Not Be Used
The use of botulinum toxin as a drug for the treatment of disorders and diseases reported in the "Indications" chapter is not indicated in the following cases:
- Allergy known to botulinum toxin or to any of the excipients contained in the medicinal product to be used;
- In patients suffering from pathologies involving muscles and nerves, such as peripheral neuropathy, myasthenia gravis, Lambert-Eaton syndrome, amyotrophic lateral sclerosis, etc .;
- In the presence of infections or inflammations developed at the injection site;
- If you are being treated for urinary incontinence and do not want to use a catheter when needed;
- In pregnancy and during breastfeeding .
Furthermore, as regards botulinum toxin type A, its use is also contraindicated in children under two years of age ; while as far as botulinum toxin type B is concerned, its use is also contraindicated in children and adolescents under 18 years of age .
Please note
Some specialty medicines based on botulinum toxin type A are also contraindicated in children and adolescents under 18 years of age. Therefore, it is always necessary to consult the package insert of the medicinal product to be used. However, the problem should not arise as botulinum toxin can be handled and administered only by specialized medical personnel who, therefore, should be aware of all the contraindications of the medicinal product that they are going to use.
