BOTOX onabotulinumtoxinA See What's Possible.

Full Product Information Including Boxed Warning | Medication Guide

What Are the Most Common Side Effects?

During the clinical trials for BOTOX® (onabotulinumtoxinA), the most common side effects reported within the first 12 weeks were1:

  • Urinary tract infection (UTI)
  • Urinary retention (not being able to empty the bladder completely)
  • Hematuria (blood in the urine)
  • Fatigue
  • Insomnia

Urinary tract infection occurred in 24% (64 out of 262) of patients who received BOTOX® compared with 17% (47 out of 272) of patients receiving placebo.1

Urinary retention (not being able to fully empty the bladder) occurred in 17% (45 out of 262) of patients who received BOTOX® compared with 3% (8 out of 272) for placebo.1

  • This may require you to use a catheter,1 a tube inserted into the bladder to allow it to drain completely2
  • Clean intermittent catheterization (CIC) is a way to manage incomplete bladder emptying.3 The catheter is not left in but is used as needed, usually about 4 times a day.3,4 You wash and dry the catheter or use a new one each time.4 You can do it yourself or someone can do it for you3
  • Among patients who were not already using a catheter before the clinical trials, 31% (33/108) began using a catheter at any time during treatment compared with 7% (7/104) for placebo1
  • Before you and your physician choose BOTOX® treatment, you should discuss the possibility that you may need to use a catheter after treatment, and you should be willing and able to use a catheter if needed1

Hematuria (blood in the urine) occurred in 4% (10/262) of BOTOX® patients compared with 3% (8/272) for placebo.1 Fatigue occurred in 4% (10/262) of BOTOX® patients compared with 1% (3/272) for placebo.1 Insomnia occurred in 2% (4/262) of BOTOX® patients compared with 0% (0/272) for placebo.1

This list does not cover all the possible side effects of BOTOX®. Please refer to the Important Safety Information and full Product Information including Boxed Warning and Medication Guide. You should also talk with your doctor.

If you have tried an anticholinergic medication and you still have leakage or experience too many side effects, please talk with your urologist about the risks and benefits to you of receiving treatment with BOTOX® for urinary incontinence due to a neurologic condition.


BOTOX® is a prescription medicine that is injected into the bladder muscle and used:

  • To treat overactive bladder symptoms such as a strong need to urinate with leakage or wetting accidents; urgency and frequency in adults when another type of medication (anticholinergic) does not work well enough or cannot be taken
  • To treat leakage of urine (incontinence) in adults, with overactive bladder due to neurologic condition, who still have leakage or cannot tolerate the side effects after trying an anticholinergic medication

BOTOX® may cause serious side effects that can be life threatening. Get medical help right away if you have any of these problems any time (hours to weeks) after injection of BOTOX®:

  • Problems swallowing, speaking, or breathing, due to weakening of associated muscles, can be severe and result in loss of life. You are at the highest risk if these problems are pre-existing before injection. Swallowing problems may last for several months.
  • Spread of toxin effects. The effect of botulinum toxin may affect areas away from the injection site and cause serious symptoms including: loss of strength and all-over muscle weakness, double vision, blurred vision and drooping eyelids, hoarseness or change or loss of voice, trouble saying words clearly, loss of bladder control, trouble breathing, trouble swallowing.

BOTOX® may cause loss of strength or general muscle weakness, vision problems, or dizziness within hours to weeks of taking BOTOX®. If this happens, do not drive a car, operate machinery, or do other dangerous activities.

Do not take BOTOX® if you: are allergic to any of the ingredients in BOTOX® (see Medication Guide for ingredients); had an allergic reaction to any other botulinum toxin product such as Myobloc® (rimabotulinumtoxinB), Dysport® (abobotulinumtoxinA), or Xeomin® (incobotulinumtoxinA); have an infection at the planned injection site.

Do not take BOTOX® for the treatment of urinary incontinence if you: have a urinary tract infection (UTI) or cannot empty your bladder on your own (and are not routinely catheterizing). Due to the risk of urinary retention (difficulty fully emptying the bladder), only patients who are willing and able to initiate catheterization post-treatment, if required, should be considered for treatment.

Patients treated for overactive bladder due to neurologic condition
In clinical trials, 30.6% of patients (33/108) who were not using clean intermittent catheterization (CIC) prior to injection, required catheterization for urinary retention following treatment with BOTOX® 200 Units as compared to 6.7% of patients (7/104) treated with placebo. The median duration of post-injection catheterization for these patients treated with BOTOX® 200 Units (n=33) was 289 days (minimum 1 day to maximum 530 days) as compared to a median duration 358 days (minimum 2 days to maximum 379 days) for patients receiving placebo (n=7). Among patients not using CIC at baseline, those with MS were more likely to require CIC post-injection than those with SCI.

The dose of BOTOX® is not the same as, or comparable to, another botulinum toxin product.

Serious and/or immediate allergic reactions have been reported. They include itching, rash, red itchy welts, wheezing, asthma symptoms, or dizziness or feeling faint. Get medical help right away if you experience symptoms; further injection of BOTOX® should be discontinued.

Tell your doctor about all your muscle or nerve conditions such as ALS or Lou Gehrig's disease, myasthenia gravis, or Lambert-Eaton syndrome, as you may be at increased risk of serious side effects including difficulty swallowing and difficulty breathing from typical doses of BOTOX®.

For patients treated for overactive bladder due to a neurologic condition:

Tell your doctor if you have any breathing-related problems. Your doctor will want to monitor you for any breathing problems during your treatment with BOTOX® for overactive bladder associated with a neurologic condition. The risk of pulmonary effects in patients with compromised respiratory status is increased in patients receiving BOTOX®.

Autonomic dysreflexia Autonomic dysreflexia associated with intradetrusor injections of BOTOX® could occur in patients treated for detrusor overactivity associated with a neurologic condition and may require prompt medical therapy. In clinical trials, the incidence of autonomic dysreflexia was greater in patients treated with BOTOX® 200 Units compared with placebo (1.5% versus 0.4%, respectively).

Tell your doctor about all your medical conditions, including if you: have or have had bleeding problems; have plans to have surgery; have symptoms of a urinary tract infection (UTI) and are being treated for urinary incontinence. Symptoms of a urinary tract infection may include pain or burning with urination, frequent urination, or fever; have problems emptying your bladder on your own and are being treated for urinary incontinence; are pregnant or plan to become pregnant (it is not known if BOTOX® can harm your unborn baby); are breastfeeding or plan to (it is not known if BOTOX® passes into breast milk).

Tell your doctor about all the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal products. Using BOTOX® with certain other medicines may cause serious side effects. Do not start any new medicines until you have told your doctor that you have received BOTOX® in the past.

Tell your doctor if you have received any other botulinum toxin product in the last 4 months; have received injections of botulinum toxin such as Myobloc®, Dysport®, or Xeomin® in the past (Tell your doctor exactly which product you received); have recently received an antibiotic by injection; take muscle relaxants; take an allergy or cold medicine; take a sleep medicine; take aspirin-like products or blood thinners.

Other side effects of BOTOX® include: urinary tract infection, painful urination, and/or inability to empty your bladder on your own. If you have difficulty fully emptying your bladder after receiving BOTOX®, you may need to use disposable self-catheters to empty your bladder up to a few times each day until your bladder is able to start emptying again. Other side effects include dry mouth, discomfort or pain at the injection site, tiredness, headache, neck pain, and eye problems: double vision, blurred vision, decreased eyesight, drooping eyelids, swelling of your eyelids, and dry eyes.

For more information refer to the Medication Guide or talk with your doctor.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.

Please see BOTOX® full Product Information including Boxed Warning and Medication Guide.

  1. BOTOX® Prescribing Information, November 2011.
  2. Mosby's Dictionary of Medicine, Nursing & Health Professions. 7th ed. Myers T, ed. St. Louis, MO: Mosby Elsevier; 2006.
  3. Wyndaele JJ, et al. Neurourol Urodyn. 2010;29(4):662-669.
  4. Abrams P, et al. Urology. 2003;61(1):37-49.

Myobloc® is a registered trademark of Solstice Neurosciences, Inc. Dysport® is a registered trademark of Ipsen Biopharm Limited Company. Xeomin® is a registered trademark of Merz Pharma GmbH & Co KGaA.

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