BOTOX® (Botulinum Toxin Type A)

Purified Neurotoxin Complex

Manufactured by:

Allergan Pharmaceuticals (Ireland) Ltd.

a subsidiary of:

Allergan, Inc., 2525 Dupont Dr., Irvine, CA 92612

 

Description: BOTOX® (Botulinum Toxin Type A) Purified Neurotoxin Complex is a sterile, vacuum-dried purified botulinum toxin type A, produced from fermentation of Hall strain Clostridium botulinum type A grown in a medium containing casein hydrolysate, glucose and yeast extract. It is purified from the culture solution by dialysis and a series of acid precipitations to a complex consisting of the neurotoxin, and several accessory proteins. The complex is dissolved in sterile sodium chloride solution containing albumin human and is sterile filtered (0.2 microns) prior to filling and vacuum-drying.

One unit (U) of BOTOXÒ corresponds to the calculated median intraperitoneal lethal dose (LD50) in mice. The method utilized for performing the assay is specific to Allergan’s product, BOTOXÒ . Due to specific details of this assay such as the vehicle, dilution scheme and laboratory protocols for the various mouse LD50 assays, Units of biological activity of BOTOXÒ cannot be compared to nor converted into Units of any other botulinum toxin or any toxin assessed with any other specific assay method. Therefore, differences in species sensitivities to different botulinum neurotoxin serotypes precludes extrapolation of animal-dose activity relationships to human dose estimates. The specific activity of BOTOXÒ is approximately 20 units/nanogram of neurotoxin protein complex.

Each vial of BOTOX® contains 100 units (U) of Clostridium botulinum type A neurotoxin complex, 0.5 milligrams of albumin (human), and 0.9 milligrams of sodium chloride in a sterile, vacuum-dried form without a preservative.

Clinical Pharmacology: BOTOX® blocks neuromuscular transmission by binding to acceptor sites on motor nerve terminals, entering the nerve terminals, and inhibiting the release of acetylcholine. This inhibition occurs as the neurotoxin cleaves SNAP-25, a protein integral to the successful docking and release of acetylcholine from vesicles situated within nerve endings. When injected intramuscularly at therapeutic doses, BOTOX® produces partial chemical denervation of the muscle resulting in a localized reduction in muscle activity. In addition, the muscle may atrophy, axonal sprouting may occur, and extrajunctional acetylcholine receptors may develop. There is evidence that reinnervation of the muscle may occur, thus slowly reversing muscle denervation produced by BOTOX®.

Pharmacokinetics

Botulinum Toxin Type A is not expected to be present in the peripheral blood at measurable levels following IM injection at the recommended doses. The recommended quantities of neurotoxin administered at each treatment session are not expected to result in systemic, overt distant clinical effects, i.e. muscle weakness, in patients without other neuromuscular dysfunction. However, sub-clinical systemic effects have been shown by single-fiber electromyography after IM doses of botulinum toxins appropriate to produce clinically observable local muscle weakness.

Clinical Studies:

Cervical dystonia:

A phase 3 randomized, multi-center, double blind, placebo-controlled study of the treatment of cervical dystonia was conducted.1 This study enrolled adult patients with cervical dystonia and a history of having received BOTOX® in an open label manner with perceived good response and tolerable side effects. Patients were excluded if they had previously received surgical or other denervation treatment for their symptoms or had a known history of neuromuscular disorder. Subjects participated in an open label enrichment period where they received their previously employed dose of BOTOX®. Only patients who were again perceived as showing a response were advanced to the randomized evaluation period. The muscles in which the blinded study agent injections were to be administered were determined on an individual patient basis.

There were 214 subjects evaluated for the open label period, of which 170 progressed into the randomized, blinded treatment period (88 in the BOTOXÒ group, 82 in the placebo group). Patient evaluations continued for at least 10 weeks post-injection. The primary outcome for the study was a dual endpoint, requiring evidence of both a change in the Cervical Dystonia Severity Scale (CDSS) and an increase in the percentage of patients showing any improvement on the Physicians Global Assessment Scale at 6 weeks after the injection session. The CDSS quantifies the severity of abnormal head positioning and was newly devised for this study. CDSS allots 1 point for each 5 degrees (or part thereof) of head deviation in each of the three planes of head movement (range of scores up to theoretical maximum of 54). The Physician Global Assessment Scale is a 9 category scale scoring the physician’s evaluation of the patients’ status compared to baseline, ranging from —4 to +4 (very marked worsening to complete improvement), with 0 indicating no change from baseline and +1 slight improvement. Pain is also an important symptom of cervical dystonia and was evaluated by separate assessments of pain frequency and severity on scales of 0 (no pain) to 4 (constant in frequency or extremely severe in intensity). Study results on the primary endpoints and the pain-related secondary endpoints are shown in Table 1.

Table 1: Efficacy Outcomes of the Phase 3 Cervical Dystonia Study (Group Means)

 

Placebo N=82

BOTOXÒ N=88

95% Cl on Difference

Baseline CDSS

9.3

9.2

 

Change in CDSS at Week 6

-0.3

-1.3

(-2.3, 0.3)[a,b]

Percentage Patients with Any Improvement on Physicians Global Assessment

31%

51%

(5%, 34%)[a]

Pain Intensity Baseline

1.8

1.8

 

Change in Pain Intensity at Week 6

-0.1

-0.4

(-0.7, -0.2)[c]

Pain Frequency Baseline

1.9

1.8

 

Change in Pain Frequency at Week 6

-0.0

-0.3

(-0.5, -0.0)[c]

[a] Confidence intervals are constructed from the analysis of covariance table with treatment and investigational site as main effects, and baseline CDSS as a covariate.

[b] These values represent the prospectively planned method for missing data imputation and statistical test. Sensitivity analyses indicated that the 95% confidence interval excluded the value of no difference between groups and the p-value was less than 0.05. These analyses included several alternative missing data imputation methods and non-parametric statistical tests.

[c] Confidence intervals are based on the t-distribution.

Exploratory analyses of this study suggested that the majority of patients who had shown a beneficial response by week 6 had returned to their baseline status by 3 months after treatment. Exploratory analyses of subsets by patient sex and age suggest that both sexes receive benefit, although female patients may receive somewhat greater amounts than male patients. There is a consistent treatment-associated effect between subsets greater than and less than age 65 (see also Precautions: Geriatrics). There were too few non-Caucasian patients enrolled to draw any conclusions regarding relative efficacy in racial subsets.

There were several randomized studies conducted prior to the phase 3 study which were supportive but not adequately designed to assess or quantitatively estimate the efficacy of BOTOX®.

In the phase 3 study the median total BOTOX® dose in patients randomized to receive BOTOXÒ (n=88) was 236 U, with 25th to 75th percentile ranges of 198 to 300 U. Of these 88 patients, most received injections to 3 or 4 muscles; 38 received injections to 3 muscles, 28 to 4 muscles, 5 to 5 muscles and 5 to 2 muscles. The dose was divided amongst the affected muscles in quantities shown in Table 2. The total dose and muscles selected were tailored to meet individual patient needs.

Table 2: Number of Patients Treated Per Muscle and

Fraction of Total Dose Injected into Involved Muscles

 

Muscle*

Number of Patients Treated in this Muscle (N=88)

Mean % Dose per Muscle

Mid-Range of % Dose per Muscle*

Splenius capitis/cervicis

83

38

25-50

Sternocleidomastoid

77

25

17-31

Levator scapulae

52

20

16-25

Trapezius

49

29

18-33

Semispinalis

16

21

13-25

Scalene

15

15

6-21

Longissimus

8

29

17-41

*The mid-range of dose is calculated as the 25th to 75th percentiles.

NOTE: There were 16 patients who had additional muscles injected.

Blepharospasm:

Botulinum toxin has been investigated for use in patients with blepharospasm in several studies. In an open label uncontrolled study, 27 patients with essential blepharospasm were injected with 2.0 U of BOTOX® at each of six sites on each side. One patient had not received any prior treatment. Twenty-six of the patients had not responded to therapy with benztropine mesylate, clonazepam and/or baclofen. Three of the 26 patients continued to experience spasms following muscle stripping surgery. Twenty-five of the 27 patients treated with botulinum toxin reported improvement within 48 hours. One patient was controlled with a higher dosage at 13 weeks post initial injection and one patient reported mild improvement but remained functionally impaired.2

In another study, 12 patients with blepharospasm were evaluated in a double-blind, placebo-controlled study. Patients receiving botulinum toxin (n=8) improved compared with the placebo group (n=4). The mean dystonia score improved by 72%, the self-assessment score rating improved by 61%, and a videotape evaluation rating improved by 39%. The effects of the treatment lasted a mean of 12.5 weeks.3

One thousand six hundred eighty-four patients with blepharospasm who were evaluated in an open label trial showed clinical improvement as evaluated by measured eyelid force and clinically observed intensity of lid spasm, lasting an average of 12.5 weeks prior to the need for re-treatment.4

 

Strabismus:

It is postulated that when used for the treatment of strabismus, the administration of BOTOX® affects muscle pairs by inducing an atrophic lengthening of the injected muscle and a corresponding shortening of the muscle’s antagonist; it was on the basis of this hypothesis that clinical studies were conducted. Six hundred seventy-seven patients with strabismus treated with one or more injections of BOTOX® were evaluated in an open label trial. Fifty-five percent of these patients improved to an alignment of 10 prism diopters or less when evaluated six months or more following injection.5 These results are consistent with results from additional open label trials which were conducted for this indication.4

Indications and Usage:

BOTOX® is indicated for the treatment of cervical dystonia in adults to decrease the severity of abnormal head position and neck pain associated with cervical dystonia.

BOTOX® is indicated for the treatment of strabismus and blepharospasm associated with dystonia, including benign essential blepharospasm or VII nerve disorders in patients 12 years of age and above.

The efficacy of BOTOX® treatment in deviations over 50 prism diopters, in restrictive strabismus, in Duane's syndrome with lateral rectus weakness, and in secondary strabismus caused by prior surgical over-recession of the antagonist has not been established. BOTOX® is ineffective in chronic paralytic strabismus except when used in conjunction with surgical repair to reduce antagonist contracture.

Contraindications: BOTOX® is contraindicated in the presence of infection at the proposed injection site(s) and in individuals with known hypersensitivity to any ingredient in the formulation.

Warnings:

The recommended dosage and frequency of administration for BOTOX® should not be exceeded. Risks resulting from administration at higher dosages are not known.

Individuals with peripheral motor neuropathic diseases (e.g., amyotrophic lateral sclerosis, or motor neuropathy) or neuromuscular junctional disorders (e.g., myasthenia gravis or Lambert-Eaton syndrome) should only receive BOTOX® with caution. Patients with neuromuscular disorders may be at increased risk of clinically significant systemic effects including severe dysphagia and respiratory compromise from typical doses of BOTOX®. Published medical literature has reported rare cases of administration of a botulinum toxin to patients with known or unrecognized neuromuscular disorders where the patients have shown extreme sensitivity to the systemic effects of typical clinical doses. In some of these cases, dysphagia has lasted several months and required placement of a gastric feeding tube.

Dysphagia is a commonly reported adverse event following treatment of cervical dystonia patients with all botulinum toxins. In these patients, there are reports of rare cases of dysphagia severe enough to warrant the insertion of a gastric feeding tube. There are also rare case reports where subsequent to the finding of dysphagia a patient developed aspiration pneumonia and died.

This product contains albumin, a derivative of human blood. Based on effective donor screening and product manufacturing processes, it carries an extremely remote risk for transmission of viral diseases. A theoretical risk for transmission of Creutzfeldt-Jakob disease (CJD) also is considered extremely remote. No cases of transmission of viral diseases or CJD have ever been identified for albumin.

Precautions:

General: Epinephrine should be available or other precautionary methods taken as necessary should an anaphylactic reaction occur.

The safe and effective use of BOTOX® depends upon proper storage of the product, selection of the correct dose, and proper reconstitution and administration techniques. Physicians administering BOTOX® must understand the relevant neuromuscular and/or orbital anatomy of the area involved and any alterations to the anatomy due to prior surgical procedures. An understanding of standard electromyographic techniques is also required for treatment of strabismus and may be useful for the treatment of cervical dystonia.

Caution should be used when BOTOX® treatment is used in the presence of inflammation at the proposed injection site(s) or when excessive weakness or atrophy is present in the target muscle(s).

Cervical Dystonia:

Patients with smaller neck muscle mass and patients who require bilateral injections into the sternocleidomastoid muscle have been reported to be at greater risk for dysphagia. Limiting the dose injected into the sternocleidomastoid muscle may reduce the occurrence of dysphagia. Injections into the levator scapulae may be associated with an increased risk of upper respiratory infection and dysphagia.

Blepharospasm:

Reduced blinking from BOTOX® injection of the orbicularis muscle can lead to corneal exposure, persistent epithelial defect and corneal ulceration, especially in patients with VII nerve disorders. One case of corneal perforation in an aphakic eye requiring corneal grafting has occurred because of this effect. Careful testing of corneal sensation in eyes previously operated upon, avoidance of injection into the lower lid area to avoid ectropion, and vigorous treatment of any epithelial defect should be employed. This may require protective drops, ointment, therapeutic soft contact lenses, or closure of the eye by patching or other means.

Strabismus:

During the administration of BOTOX® for the treatment of strabismus, retrobulbar hemorrhages sufficient to compromise retinal circulation have occurred from needle penetrations into the orbit. It is recommended that appropriate instruments to decompress the orbit be accessible. Ocular (globe) penetrations by needles have also occurred. An ophthalmoscope to diagnose this condition should be available. Inducing paralysis in one or more extraocular muscles may produce spatial disorientation, double vision or past pointing. Covering the affected eye may alleviate these symptoms.

Information for Patients:

Patients or caregivers should be advised to seek immediate medical attention if swallowing, speech or respiratory disorders arise.

Patients with cervical dystonia should be informed of the possibility of experiencing dysphagia, which is typically mild to moderate, but could be severe. Rare consequences of severe dysphagia include aspiration, dyspnea, pneumonia, and the need to reestablish an airway.

As with any treatment with the potential to allow previously sedentary patients to resume activities, the sedentary patient should be cautioned to resume activity gradually following the administration of BOTOX®.

Drug Interactions:

Co-administration of BOTOX® and aminoglycosides6 or other agents interfering with neuromuscular transmission (e.g., curare-like compounds) should only be performed with caution as the effect of the toxin may be potentiated.

The effect of administering different botulinum neurotoxin serotypes at the same time or within several months of each other is unknown. Excessive neuromuscular weakness may be exacerbated by administration of another botulinum toxin prior to the resolution of the effects of a previously administered botulinum toxin.

Pregnancy: Pregnancy Category C

When pregnant mice and rats were injected intramuscularly during the period of organogenesis, the developmental NOEL of BOTOX® was 4 U/kg. Higher doses (8 or 16 U/kg) were associated with reductions in fetal body weights and/or delayed ossification which may be reversible.

In a range finding study in rabbits, daily injection of 0.125 U/kg/day (days 6 to 18 of gestation) and 2 U/kg (days 6 and 13 of gestation) produced severe maternal toxicity, abortions and/or fetal malformations. Higher doses resulted in death of the dams. The rabbit appears to be a very sensitive species to BOTOX®.

There are no adequate and well-controlled studies of BOTOX® in pregnant women. Because animal reproductive studies are not always predictive of human response, BOTOX® should be administered during pregnancy only if the potential benefit justifies the potential risk to the fetus. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential risks, including abortion or fetal malformations which have been observed in rabbits.

Carcinogenesis, Mutagenesis, Impairment of fertility: Long term studies in animals have not been performed to evaluate carcinogenic potential of BOTOX®.

The reproductive NOEL following intramuscular injection of 0, 4, 8, and 16 U/kg was 4 U/kg in male rats and 8 U/kg in female rats. Higher doses were associated with dose-dependent reductions in fertility in male rats (where limb weakness resulted in the inability to mate), and an altered estrous cycle in female rats. There were no adverse effects on the viability of the embryos.

Nursing mothers: It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when BOTOX® is administered to a nursing woman.

Pediatric use: Safety and effectiveness in children below the age of 12 have not been established for blepharospasm or strabismus, or below the age of 16 for cervical dystonia.

Geriatric use: Clinical studies of BOTOX® did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. There were too few patients over the age of 75 to enable any comparisons. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Adverse Reactions:

General:

There have been rare spontaneous reports of death, sometimes associated with dysphagia, pneumonia, and/or other significant debility, after treatment with botulinum toxin.

There have also been rare reports of adverse events involving the cardiovascular system, including arrhythmia and myocardial infarction, some with fatal outcomes. Some of these patients had risk factors including cardiovascular disease. The exact relationship of these events to the botulinum toxin injection has not been established.

The following events have been reported since the drug has been marketed and a causal relationship to the botulinum toxin injected is unknown: skin rash (including erythema multiforme, urticaria and psoriasiform eruption), pruritus, and allergic reaction.

In general, adverse events occur within the first week following injection of BOTOX® and while generally transient may have a duration of several months. Localized pain, tenderness and/or bruising may be associated with the injection. Local weakness of the injected muscle(s) represents the expected pharmacological action of botulinum toxin. However, weakness of adjacent muscles may also occur due to spread of toxin.

Cervical Dystonia:

In cervical dystonia patients evaluated for safety in double-blind and open-label studies following injection of BOTOX®, the most frequently reported adverse reactions were dysphagia (19%), upper respiratory infection (12%), neck pain (11%), and headache (11%).7

Other events reported in 2-10% of patients in any one study in decreasing order of incidence include: increased cough, flu syndrome, back pain, rhinitis, dizziness, hypertonia, soreness at injection site, asthenia, oral dryness, speech disorder, fever, nausea, and drowsiness. Stiffness, numbness, diplopia, ptosis, and dyspnea have been reported rarely.

Dysphagia and symptomatic general weakness may be attributable to an extension of the pharmacology of BOTOX® resulting from the spread of the toxin outside the injected muscles.

The most common severe adverse event associated with the use of BOTOX® injection in patients with cervical dystonia is dysphagia with about 20% of these cases also reporting dyspnea. (See Warnings). Most dysphagia is reported as mild or moderate in severity. However, it may rarely be associated with more severe signs and symptoms (See Warnings).

Additionally, reports in the literature include a case of a female patient who developed brachial plexopathy two days after injection of 120 U of BOTOX® for the treatment of cervical dystonia, and reports of dysphonia in patients who have been treated for cervical dystonia.

Blepharospasm:

In a study of blepharospasm patients who received an average dose per eye of 33 U (injected at 3 to 5 sites) of the currently manufactured BOTOX®, the most frequently reported treatment-related adverse reactions were ptosis (20.8%), superficial punctate keratitis (6.3%) and eye dryness (6.3%).8

In this study, the rate for ptosis in the current BOTOX® treated group (20.8% of patients) was significantly higher than the original BOTOX® treated group (4.0% of patients) (p=0.014%). All of these events were mild or moderate except for one case of ptosis which was rated severe.

Other events reported in prior clinical studies in decreasing order of incidence include: irritation, tearing, lagophthalmos, photophobia, ectropion, keratitis, diplopia and entropion, diffuse skin rash and local swelling of the eyelid skin lasting for several days following eyelid injection.

In two cases of VII nerve disorder (one case of an aphakic eye), reduced blinking from BOTOX® injection of the orbicularis muscle led to serious corneal exposure, persistent epithelial defect, and corneal ulceration. Perforation occurred in the aphakic eye and required corneal grafting.

A report of acute angle closure glaucoma one day after receiving an injection of botulinum toxin for blepharospasm was received, with recovery four months later after laser iridotomy and trabeculectomy. Focal facial paralysis, syncope and exacerbation of myasthenia gravis have also been reported after treatment of blepharospasm.

Strabismus:

Extraocular muscles adjacent to the injection site can be affected, causing ptosis or vertical deviation, especially with higher doses of BOTOX®. The incidence rates of these adverse effects in 2058 adults who received a total of 3650 injections for horizontal strabismus are 15.7% and 16.9%, respectively:4

Inducing paralysis in one or more extraocular muscles may produce spatial disorientation, double vision, or past-pointing. Covering the affected eye may alleviate these symptoms.

The incidence of ptosis was 0.9% after inferior rectus injection and 37.7% after superior rectus injection.

Ptosis (0.3%) and vertical deviation greater than two prism diopters (2.1%) were reported to persist for over six months in a larger series of 5587 injections of horizontal muscles in 3104 patients.

In these patients, the injection procedure itself caused nine scleral perforations. A vitreous hemorrhage occurred in one case and later cleared. No retinal detachment or visual loss occurred in any case. Sixteen retrobulbar hemorrhages occurred without visual loss. Decompression of the orbit after five minutes was done to restore retinal circulation in one case. Five eyes had pupillary change consistent with ciliary ganglion damage (Adie's pupil).

One patient developed anterior segment ischemia after receiving BOTOX® injection into the medial rectus muscle under direct visualization for esotropia.

Immunogenicity:

Formation of neutralizing antibodies to botulinum toxin type A may reduce the effectiveness of BOTOX® treatment by inactivating the biological activity of the toxin. The rate of formation of neutralizing antibodies in patients receiving BOTOX® has not been well studied.

In the phase 3 cervical dystonia study1 that enrolled only patients with a history of receiving BOTOX® for multiple treatment sessions, at study entry there were 192 patients with antibody assay results, of whom 33 (17%) had a positive assay for neutralizing activity. There were 96 patients in the randomized period of the phase 3 study with valid assays at both study entry and end and who were neutralizing activity negative at entry. Of these 96, 2 patients (2%) converted to positive for neutralizing activity. Both of these converting patients were among the 52 who had received two BOTOX® treatments between the two assays; none were in the group randomized to placebo in the controlled comparison period of the study.

In the randomized period of the phase 3 study, patients in the BOTOX® group whose baseline assays were neutralizing antibody negative showed improvements on CDSS (n=64, mean CDSS change -2.1) while patients whose baseline assays were neutralizing antibody positive did not (n=14, mean CDSS change +1.1). However, in uncontrolled studies there are also individual patients who are perceived as continuing to respond to treatments despite the presence of neutralizing activity. Not all patients who become non-responsive to BOTOX® after an initial period of clinical response have demonstrable levels of neutralizing activity.

The data reflect the patients whose test results were considered positive or negative for neutralizing activity to BOTOX® in a mouse protection assay. The results of these tests are highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of neutralizing activity in an assay may be influenced by several factors including sample handling, concomitant medications and underlying disease. For these reasons, comparison of the incidence of neutralizing activity to BOTOX® with the incidence reported to other products may be misleading.

The critical factors for neutralizing antibody formation have not been well characterized. The results from some studies suggest that BOTOX® injections at more frequent intervals or at higher doses may lead to greater incidence of antibody formation. The potential for antibody formation may be minimized by injecting with the lowest effective dose given at the longest feasible intervals between injections.

Overdosage:

Signs and symptoms of overdose are not apparent immediately post injection. Should accidental injection or oral ingestion occur, the person should be medically supervised for up to several weeks for signs or symptoms of systemic weakness or muscle paralysis.

An antitoxin is available in the event of immediate knowledge of an overdose or misinjection. In the event of an overdose or injection into the wrong muscle, immediately contact Allergan for additional information at (800) 433-8871 from 8:00 a.m. to 4:00 p.m. Pacific Time, or at (714) 246-5954 for a recorded message at other times. The antitoxin will not reverse any botulinum toxin induced muscle weakness effects already apparent by the time of antitoxin administration.

Dosage and Administration:

BOTOX® is supplied in a single use vial. Because the product and diluent do not contain a preservative, once opened and reconstituted, store in a refrigerator and use within four hours. Discard any remaining solution. Do not freeze reconstituted BOTOX®.

BOTOX® is to be reconstituted with sterile, non-preserved saline prior to intramuscular injection.

General:

An injection of BOTOX® is prepared by drawing into an appropriately sized sterile syringe an amount of the properly reconstituted toxin (see Dilution Table) slightly greater than the intended dose. Air bubbles in the syringe barrel are expelled and the syringe is attached to an appropriate injection needle. Patency of the needle should be confirmed. A new, sterile, needle and syringe should be used to enter the vial on each occasion for removal of BOTOX®.

The method utilized for performing the potency assay is specific to Allergan’s Botulinum Toxin Type A. Due to specific details of this assay such as the vehicle, dilution scheme and laboratory protocols for the various potency assays, Units of biological activity of Botulinum Toxin Type A cannot be compared to nor converted into Units of any other botulinum toxin or any toxin assessed with any other specific assay method. Therefore, differences in species sensitivities to different botulinum neurotoxin serotypes precludes extrapolation of animal dose-activity relationships to human dose relationships.

Cervical dystonia:

The phase 3 study enrolled patients who had extended histories of receiving and tolerating BOTOX® injections, with prior individualized adjustment of dose. The mean BOTOX® dose administered to patients in the phase 3 study was 236 U (25th to 75th percentile range 198 U to 300 U). The BOTOX® dose was divided among the affected muscles (see Clinical Studies: Cervical Dystonia). Dosing in initial and sequential treatment sessions should be tailored to the individual patient based on the patient’s head and neck position, localization of pain, muscle hypertrophy, patient response and adverse event history.

The initial dose for a patient without prior use of BOTOX® should be at a lower dose, with subsequent dosing adjusted based on individual response. Limiting the total dose injected into the sternocleidomastoid muscles to 100 U or less may decrease the occurrence of dysphagia (see Precautions: Cervical Dystonia).

A 25, 27 or 30 gauge needle may be used for superficial muscles, and a longer 22 gauge needle may be used for deeper musculature. Localization of the involved muscles with electromyographic guidance may be useful.

Clinical improvement generally begins within the first two weeks after injection with maximum clinical benefit at approximately six weeks post-injection. In the phase 3 study most subjects were observed to have returned to pre-treatment status by 3 months post-treatment.

Blepharospasm:

For blepharospasm, reconstituted BOTOX® (see Dilution Table) is injected using a sterile, 27 - 30 gauge needle without electromyographic guidance. The initial recommended dose is 1.25 - 2.5 U (0.05 mL to 0.1 mL volume at each site) injected into the medial and lateral pre-tarsal orbicularis oculi of the upper lid and into the lateral pre-tarsal orbicularis oculi of the lower lid. Avoiding injection near the levator palpebrae superioris may reduce the complication of ptosis. Avoiding medial lower lid injections, and thereby reducing diffusion into the inferior oblique, may reduce the complication of diplopia. Ecchymosis occurs easily in the soft eyelid tissues. This can be prevented by applying pressure at the injection site immediately after the injection.

In general, the initial effect of the injections is seen within three days and reaches a peak at one to two weeks post-treatment. Each treatment lasts approximately three months, following which the procedure can be repeated. At repeat treatment sessions, the dose may be increased up to two-fold if the response from the initial treatment is considered insufficient-usually defined as an effect that does not last longer than two months. However there appears to be little benefit obtainable from injecting more than 5.0 U per site. Some tolerance may be found when BOTOX® is used in treating blepharospasm if treatments are given any more frequently than every three months, and is rare to have the effect be permanent.

The cumulative dose of BOTOX® treatment in a 30-day period should not exceed 200 U.

Strabismus:

BOTOX® is intended for injection into extraocular muscles utilizing the electrical activity recorded from the tip of the injection needle as a guide to placement within the target muscle. Injection without surgical exposure or electromyographic guidance should not be attempted. Physicians should be familiar with electromyographic technique.

To prepare the eye for BOTOX® injection, it is recommended that several drops of a local anesthetic and an ocular decongestant be given several minutes prior to injection.

Note: The volume of BOTOX® injected for treatment of strabismus should be between 0.05 - 0.15 mL per muscle.

The initial listed doses of the reconstituted BOTOX® (see Dilution Table below) typically create paralysis of injected muscles beginning one to two days after injection and increasing in intensity during the first week. The paralysis lasts for 2-6 weeks and gradually resolves over a similar time period. Overcorrections lasting over six months have been rare. About one half of patients will require subsequent doses because of inadequate paralytic response of the muscle to the initial dose, or because of mechanical factors such as large deviations or restrictions, or because of the lack of binocular motor fusion to stabilize the alignment.

I. Initial doses in Units (abbreviated as U). Use the lower listed doses for treatment of small deviations. Use the larger doses only for large deviations.

A. For vertical muscles, and for horizontal strabismus of less than 20 prism diopters: 1.25 - 2.5 U in any one muscle.

B. For horizontal strabismus of 20 prism diopters to 50 prism diopters: 2.5 - 5.0 U in any one muscle.

C. For persistent VI nerve palsy of one month or longer duration: 1.25 - 2.5 U in the medial rectus muscle.

II. Subsequent doses for residual or recurrent strabismus.

  1. It is recommended that patients be re-examined 7-14 days after each injection to assess the effect of that dose.
  2. Patients experiencing adequate paralysis of the target muscle that require subsequent injections should receive a dose comparable to the initial dose.
  3. Subsequent doses for patients experiencing incomplete paralysis of the target muscle may be increased up to two-fold compared to the previously administered dose.
  4. Subsequent injections should not be administered until the effects of the previous dose have dissipated as evidenced by substantial function in the injected and adjacent muscles.
  5. The maximum recommended dose as a single injection for any one muscle is 25 U.

Dilution Technique:

Prior to injection, reconstitute vacuum-dried BOTOX®, with sterile normal saline without a preservative; 0.9% Sodium Chloride Injection is the recommended diluent. Draw up the proper amount of diluent in the appropriate size syringe, and slowly inject the diluent into the vial. Discard the vial if a vacuum does not pull the diluent into the vial. Gently mix BOTOX® with the saline by rotating the vial. Record the date and time of reconstitution on the space on the label. BOTOX® should be administered within four hours after reconstitution.

During this time period, reconstituted BOTOX® should be stored in a refrigerator (2° to 8°C). Reconstituted BOTOX® should be clear, colorless and free of particulate matter. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration and whenever the solution and the container permit.

Dilution Table

Diluent Added

(0.9% Sodium Chloride Injection)

Resulting dose

Units per 0.1 mL

1.0 mL

2.0 mL

4.0 mL

8.0 mL

10.0 U

5.0U

2.5U

1.25U

Note: These dilutions are calculated for an injection volume of 0.1 mL. A decrease or increase in the BOTOX® dose is also possible by administering a smaller or larger injection volume - from 0.05 mL (50% decrease in dose) to 0.15 mL (50% increase in dose.)

How Supplied: BOTOX® is supplied in a single use vial. Each vial contains 100 U of vacuum-dried Clostridium botulinum type A neurotoxin complex. NDC 0023-1145-01.

Rx Only

Single use vial.

Storage:

Store the vacuum-dried product in a freezer at or below -5°C. Administer BOTOX® within four hours after the vial is removed from the freezer and reconstituted. During this four hours, reconstituted BOTOX® should be stored in a refrigerator (2° to 8°C). Reconstituted BOTOX® should be clear, colorless and free of particulate matter.

All vials, including expired vials, or equipment used with the drug should be disposed of carefully as is done with all medical waste.

Revised: December, 2000

Manufactured by:

Allergan Pharmaceuticals (Ireland) Ltd.

a subsidiary of: Allergan, Inc., 2525 Dupont Dr., Irvine, CA 92612

References:

1. Data on file, Allergan, Inc. A randomized, multicenter, double-blind, placebo-controlled study of intramuscular BOTOX® (botulinum toxin type A) purified neurotoxin complex (original 79-11 BOTOX®) for the treatment of cervical dystonia. 1998.

2. Arthurs B, Flanders M, Codere F, Gauthier S, Dresner S, Stone L. Treatment of blepharospasm with medication, surgery and type A botulinum toxin. Can J Ophthalmol 1987;22:24-28.

3. Jankovic J, Orman J. Botulinum A toxin for cranial-cervical dystonia: A double-blind , placebo-controlled study. Neurology 1987;37:616-623.

  1. Data on file, Allergan, Inc.
  2. Scott AB. Botulinum toxin treatment of strabismus. American Academy of Ophthalmology, Focal Points 1989:Clinical Modules for Ophthalmologists Vol VII Module 12.

  1. Wang YC, Burr DH, Korthals GJ, Sugiyama H. Acute toxicity of aminoglycoside antibiotics as an aid in detecting botulism. Appl Environ Microbiol 1984;48:951-955.
  2. Data on file, Allergan, Inc. 1999.
  3. Data on file, Allergan, Inc. A randomized, multicenter, double-blind, parallel clinical trial to compare the safety and efficacy of BOTOX® (botulinum toxin type A) purified neurotoxin complex manufactured from neurotoxin complex batch BCB2024 to that manufactured from neurotoxin complex batch 79-11 in blepharospasm patients. 1997.