OnabotulinumtoxinA (Injection, Intradermal, Intramuscular)

Beside smoothing frown lines and 'crow's feet', OnabotulinumtoxinA injections are used in the treatment of a number of different conditions, including com/health/cervical-dystonia/">cervical dystonia, strabismus, blepharospasm, severe headaches, incontinence, upper limb spasticity, and overactive underarm sweating.


OnabotulinumtoxinA injections (also known as Botox and Botox Cosmetic) are used to treat a wide variety of medical conditions, as well as having cosmetic uses. OnabotulinumtoxinA (Botox) intramuscular injections are used to relieve:

  • Cervical dystonia (uncontrolled tightening of neck muscles that can cause abnormal head positions and severe neck pain also known as spasmodic torticollis) in adults and teenagers over the age of 16

OnabotulinumtoxinA injections (Botox Cosmetic) are used to:

  • Temporarily smooth 'frown lines' (wrinkles that appear between the eyebrows) in adults over the age of 18

OnabotulinumtoxinA injections belong to a group of medicines known as neurotoxins. They work by blocking the nerve signals in a muscle, which causes tightening and movement in the muscle. This makes it useful for treating a variety of muscular dysfunctions. Injecting OnabotulinumtoxinA into the bladder can decrease bladder contractions and block the nerve signals that tell the brain the bladder needs emptying. Injecting OnabotulinumtoxinA into sweat glands can cause the gland to reduce its function, which in turn can reduce unwanted or excessive sweating.

Conditions Treated

Type Of Medicine

  • Neurotoxin

Side Effects

All medicines carry the risk of causing unwanted side effects alongside their desired functions. Not all of the following side effects may present themselves in a patient, but some may require immediate medical attention if detected.

Patients who notice any of the following should contact their physician for advice immediately:

  • Breathing difficulties

Other side effects may appear which do not typically require medical attention. These side effects may disappear over the course of treatment as the body adapts to OnabotulinumtoxinA. Patients who are particularly concerned about the persistence or nature of their side effects should contact their physician or pharmacist for advice on ways to reduce or prevent them. These side effects include:

  • Drooping of the upper eyelids (when used to treat blepharospasm, strabismus or chronic migraine)

Some patients may experience side effects not listed in this guide. Patients who experience other side effects should contact their healthcare professional for more advice. New side effects can also be reported to the FDA by calling 1-800-FDA-1088.


OnabotulinumtoxinA injections are only given in a clinic or hospital by qualified staff. It is injected into a patient's muscles or just under their skin. Physicians may provide other medicine to numb the area before injecting, which may include ointment or eye drops if the shot is going to be given around the eye area. After the shot, patients having treatment around their eyes may need to wear protective patches or special contact lenses.

Patients who are receiving treatment for excess sweating should remove the hair from their underarms but should not use deodorant for at least 24 hours before the injection. Patients should also avoid hot liquids or foods, exercise, or anything else that could cause them to sweat in the hour before their scheduled treatment.

OnabotulinumtoxinA is slowly released into the body, meaning that, depending on the condition being treated, results may not be seen for a few weeks after treatment. In the treatment of neck disorders and upper arm stiffness, patients should see an improvement within six weeks after the shot. In the treatment of eyelid disorders, patients should notice an improvement within a couple of days, lasting for up to six weeks. In all cases, any improvement will usually last for up to three months, before wearing away. This may mean that patients need regular treatment to maintain the effects of OnabotulinumtoxinA. For chronic migraine patients, this usually means a treatment every 12 weeks.

OnabotulinumtoxinA will always be supplied with a medication guide, which should be given to the patient. Patients should carefully read the information and then ask any questions with their physician before treatment.

OnabotulinumtoxinA is useful in a number of specific conditions, but other botulinum toxin medications and treatments may not work in the same way and may require different doses.

Major drug interactions

Some medicines should never be taken together. Other medicines can be taken together, even if there is a chance of interactions occurring. Where there is a risk of interaction, a physician may choose to alter the dose of one or more of the patient's medicines or change the frequency or timing of doses. Patients should fully inform their physician about all medicines and substances they are taking, including prescription and over the counter medications, vitamins, supplements and herbal remedies.

Some medicines may also not be used around the time of drinking or eating, as this may cause interactions. Drinking alcohol or using tobacco can also have an effect on how a patient's medicines work, or cause side effects. Patients should discuss any concerns with their physician and disclose any drinking or smoking before treatment.

Patients who have other medical issues may also experience problems with using this medicine. Patients should tell their physician about their medical history, including any history of:

  • Thick, sebaceous skin (fatty or oily skin)


A patient's physician should regularly review their condition by scheduling appointments to check their progress while using OnabotulinumtoxinA. They should assess whether it is still working throughout the course of treatment, and decide whether continued treatment is necessary.

Severe muscle reactions have been reported after treatment with OnabotulinumtoxinA. Patients who notice sudden muscle weakness, difficulty talking, swallowing or breathing, or loss of bladder control should contact their physician immediately. For some patients, this may develop into life-threatening problems that may require urgent in-patient hospital treatment.

OnabotulinumtoxinA can also cause muscle weakness and problems with vision for some patients (including bleeding on the inside of the eye). Patients who feel weak or notice changes in their vision should avoid operating machinery, driving or doing anything else that could become dangerous.

OnabotulinumtoxinA can also reduce eye blinking, which can lead to a higher risk of developing eye problems (including ulcers and corneal exposure). Patients who notice that they are less able to blink should contact their physician immediately.

OnabotulinumtoxinA can also trigger severe allergic reactions, which can lead to anaphylactic shocks. Anaphylaxis should be treated immediately as it can be life-threatening. Patients who notice they have itching, breathing difficulties, a rash, hoarseness, difficulties swallowing, or swelling around their mouth, hands or face while using OnabotulinumtoxinA should seek medical attention immediately.

Patients who receive OnabotulinumtoxinA to treat their muscle spasms or eye problems and experience improvements may notice they are able to achieve more than they were before. They should slowly increase their activities, allowing time for their body to adapt and become stronger. Patients starting new exercise programs should check first with their physician.

OnabotulinumtoxinA can increase a patient's risk of developing upper respiratory tract infections or bronchitis when used to treat upper limb spasticity. Patients who develop breathing problems, start sneezing, get a sore throat, coughing or fever should contact their physician.

OnabotulinumtoxinA can also lead to a condition known as autonomic dysreflexia in patients who already have spinal cord injuries or nervous system disorders. Patients who notice increased sweating, a headache, redness or warmth in their face, arms or neck, a slowed heartbeat, or have urination difficulties should contact a physician immediately.

OnabotulinumtoxinA is constructed from donated human blood, which carries a small risk of transmitting blood-borne viruses to patients. Both the donors and their donated samples are thoroughly tested to keep the risk of transmission low. Patients who have any concerns about this should raise them with their physician.

Patients who notice problems with urination or a burning feeling while urinating should contact their physician urgently.

Patients are reminded to only take medicines that have been discussed with their physician while taking OnabotulinumtoxinA. Patients should discuss all substances they are taking with their physician, including prescription and over the counter medications, herbal remedies and vitamin supplements.


OnabotulinumtoxinA should only be administered in a clinic or hospital setting by qualified healthcare professionals. They should store it in its original packaging in a cool, dry place and out of the reach of children.


There are two types of botulinum toxin treatments (toxin A and toxin B). They have different uses, including treating muscle spasms, muscle stiffness, eye problems, cosmetic procedures, migraines, and overactive bladder. Different brands use different formulations, so there is no standard dosing information. A physician should make a decision on which one is the right product for the patient and their condition.

Botulinum toxin is used to treat a wide variety of different conditions, including muscle issues (such as torticollis and cervical dystonia), eye disorders (such as blepharospasm and strabismus), chronic migraines, and cosmetic issues (including crow's feet and frown lines). It works by relaxing muscle tissues by blocking the release of acetylcholine.

It is also used to treat patients who suffer from an overactive bladder and who have not previously responded to treatment with other medications, or have a poor tolerance to side effects. It reduces the urge to urinate and leakage.

OnabotulinumtoxinA also has a use in treating severe underarm sweating, by blocking the bodily chemicals that usually trigger the sweat glands.

In all cases, OnabotulinumtoxinA does not represent a cure. It offers temporary relief from symptoms, but they will gradually reappear as the medicine wears off - usually within 12 weeks.