FDA Label for Lioresal (baclofen)
View Indications, Usage & Precautions
- DESCRIPTION
- CLINICAL PHARMACOLOGY
- CONTINUOUS INFUSION:
- PHARMACOKINETICS OF LIORESAL INTRATHECAL:
- INDICATIONS AND USAGE
- CONTRAINDICATIONS
- WARNINGS
- PRECAUTIONS
- SCREENING
- PUMP IMPLANTATION
- PUMP DOSE ADJUSTMENT AND TITRATION
- CONSIDERATIONS BASED ON EXPERIENCE WITH ORAL LIORESAL (BACLOFEN USP)
- OVERDOSAGE
- TREATMENT SUGGESTIONS FOR OVERDOSE:
- DOSAGE AND ADMINISTRATION
- STABILITY
- DELIVERY SPECIFICATIONS
- DELIVERY REGIMEN:
- HOW SUPPLIED
- STORAGE
Lioresal (baclofen) Product Label
The following document was submitted to the FDA by the labeler of this product Amneal Pharmaceuticals Llc. The document includes published materials associated whith this product with the essential scientific information about this product as well as other prescribing information. Product labels may durg indications and usage, generic names, contraindications, active ingredients, strength dosage, routes of administration, appearance, warnings, inactive ingredients, etc.
Description
LIORESAL INTRATHECAL (baclofen injection) is a muscle relaxant and antispastic. Its chemical name is 4-amino-3-(4-chlorophenyl) butanoic acid, and its structural formula is:
Baclofen is a white to off-white, odorless or practically odorless crystalline powder, with a molecular weight of 213.66. It is slightly soluble in water, very slightly soluble in methanol, and insoluble in chloroform.
LIORESAL INTRATHECAL is a sterile, pyrogen-free, isotonic solution free of antioxidants, preservatives or other potentially neurotoxic additives indicated only for intrathecal administration. The drug is stable in solution at 37° C and compatible with CSF. Each milliliter of LIORESAL INTRATHECAL contains baclofen U. S. P. 50 mcg, 500 mcg or 2000 mcg and sodium chloride 9 mg in Water for Injection; pH range is 5.0 - 7.0. Each ampule is intended for SINGLE USE ONLY. Discard any unused portion. DO NOT AUTOCLAVE.
Clinical Pharmacology
The precise mechanism of action of baclofen as a muscle relaxant and antispasticity agent is not fully understood. Baclofen inhibits both monosynaptic and polysynaptic reflexes at the spinal level, possibly by decreasing excitatory neurotransmitter release from primary afferent terminals, although actions at supraspinal sites may also occur and contribute to its clinical effect. Baclofen is a structural analog of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), and may exert its effects by stimulation of the GABAB receptor subtype.
LIORESAL INTRATHECAL when introduced directly into the intrathecal space permits effective CSF concentrations to be achieved with resultant plasma concentrations 100 times less than those occurring with oral administration. In people, as well as in animals, baclofen has been shown to have general CNS depressant properties as indicated by the production of sedation with tolerance, somnolence, ataxia, and respiratory and cardiovascular depression.
Continuous Infusion:
LIORESAL INTRATHECAL'S antispastic action is first seen at 6 to 8 hours after initiation of continuous infusion. Maximum activity is observed in 24 to 48 hours.
Pharmacokinetics Of Lioresal Intrathecal:
The pharmacokinetics of CSF clearance of LIORESAL INTRATHECAL calculated from intrathecal bolus or continuous infusion studies approximates CSF turnover, suggesting elimination is by bulk-flow removal of CSF.
Indications And Usage
LIORESAL INTRATHECAL (baclofen injection) is indicated for use in the management of severe spasticity. Patients should first respond to a screening dose of intrathecal baclofen prior to consideration for long term infusion via an implantable pump. For spasticity of spinal cord origin, chronic infusion of LIORESAL INTRATHECAL via an implantable pump should be reserved for patients unresponsive to oral baclofen therapy, or those who experience intolerable CNS side effects at effective doses. Patients with spasticity due to traumatic brain injury should wait at least one year after the injury before consideration of long term intrathecal baclofen therapy. LIORESAL INTRATHECAL is intended for use by the intrathecal route in single bolus test doses (via spinal catheter or lumbar puncture) and, for chronic use, only in implantable pumps approved by the FDA specifically for the administration of LIORESAL INTRATHECAL into the intrathecal space.
Contraindications
Hypersensitivity to baclofen. LIORESAL INTRATHECAL is not recommended for intravenous, intramuscular, subcutaneous or epidural administration.
Warnings
LIORESAL INTRATHECAL is for use in single bolus intrathecal injections (via a catheter placed in the lumbar intrathecal space or injection by lumbar puncture) and in implantable pumps approved by the FDA specifically for the intrathecal administration of baclofen. Because of the possibility of potentially life-threatening CNS depression, cardiovascular collapse, and/or respiratory failure, physicians must be adequately trained and educated in chronic intrathecal infusion therapy. The pump system should not be implanted until the patient’s response to bolus LIORESAL INTRATHECAL injection is adequately evaluated. Evaluation (consisting of a screening procedure: see Dosage and Administration) requires that LIORESAL INTRATHECAL be administered into the intrathecal space via a catheter or lumbar puncture. Because of the risks associated with the screening procedure and the adjustment of dosage following pump implantation, these phases must be conducted in a medically supervised and adequately equipped environment following the instructions outlined in the Dosage and Administration section. Resuscitative equipment should be available.
Following surgical implantation of the pump, particularly during the initial phases of pump use, the patient should be monitored closely until it is certain that the patient’s response to the infusion is acceptable and reasonably stable. On each occasion that the dosing rate of the pump and/or the concentration of LIORESAL INTRATHECAL (baclofen injection) in the reservoir is adjusted, close medical monitoring is required until it is certain that the patient’s response to the infusion is acceptable and reasonably stable.
It is mandatory that the patient, all patient caregivers, and the physicians responsible for the patient receive adequate information regarding the risks of this mode of treatment. All medical personnel and caregivers should be instructed in 1) the signs and symptoms of overdose, 2) procedures to be followed in the event of overdose and 3) proper home care of the pump and insertion site.
Precautions
Children should be of sufficient body mass to accommodate the implantable pump for chronic infusion. Please consult pump manufacturer‘s manual for specific recommendations.
Safety and effectiveness in pediatric patients below the age of 4 have not been established.
Screening
Patients should be infection-free prior to the screening trial with LIORESAL INTRATHECAL (baclofen injection) because the presence of a systemic infection may interfere with an assessment of the patient’s response to bolus LIORESAL INTRATHECAL.
Pump Implantation
Patients should be infection-free prior to pump implantation because the presence of infection may increase the risk of surgical complications. Moreover, a systemic infection may complicate dosing.
Pump Dose Adjustment And Titration
In most patients, it will be necessary to increase the dose gradually over time to maintain effectiveness; a sudden requirement for substantial dose escalation typically indicates a catheter complication (i. e., catheter kink or dislodgement). Reservoir refilling must be performed by fully trained and qualified personnel following the directions provided by the pump manufacturer. Inadvertent injection into the subcutaneous tissue can occur if the reservoir refill septum is not properly accessed. Subcutaneous injection may result in symptoms of a systemic overdose or early depletion of the reservoir. Refill intervals should be carefully calculated to prevent depletion of the reservoir, as this would result in the return of severe spasticity and possibly symptoms of withdrawal.
Strict aseptic technique in filling is required to avoid bacterial contamination and serious infection. A period of observation appropriate to the clinical situation should follow each refill or manipulation of the drug reservoir.
Extreme caution must be used when filling an FDA approved implantable pump equipped with an injection port that allows direct access to the intrathecal catheter. Direct injection into the catheter through the catheter access port may cause a life-threatening overdose.
Considerations Based On Experience With Oral Lioresal (Baclofen Usp)
A dose-related increase in incidence of ovarian cysts was observed in female rats treated chronically with oral LIORESAL. Ovarian cysts have been found by palpation in about 4% of the multiple sclerosis patients who were treated with oral LIORESAL for up to one year. In most cases these cysts disappeared spontaneously while patients continued to receive the drug. Ovarian cysts are estimated to occur spontaneously in approximately 1% to 5% of the normal female population.
Overdosage
Special attention must be given to recognizing the signs and symptoms of overdosage, especially during the initial screening and dose-titration phase of treatment, but also during reintroduction of LIORESAL INTRATHECAL after a period of interruption in therapy.
Treatment Suggestions For Overdose:
There is no specific antidote for treating overdoses of LIORESAL INTRATHECAL (baclofen injection); however, the following steps should ordinarily be undertaken:
1) Residual LIORESAL INTRATHECAL solution should be removed from the pump as soon as possible.
2) Patients with respiratory depression should be intubated if necessary, until the drug is eliminated.
If lumbar puncture is not contraindicated, consideration should be given to withdrawing 30-40 mL of CSF to reduce CSF baclofen concentration.
Dosage And Administration
Refer to the manufacturer's manual for the implantable pump approved for intrathecal infusion for specific instructions and precautions for programming the pump and/or refilling the reservoir. There are various pumps with varying reservoir volumes and there are various refill kits available. It is important to be familiar with all of these products in order to select the appropriate refill kit for the particular pump in use.
Stability
Parenteral drug products should be inspected for particulate matter and discoloration prior to administration, whenever solution and container permit.
Delivery Specifications
The specific concentration that should be used depends upon the total daily dose required as well as the delivery rate of the pump. LIORESAL INTRATHECAL may require dilution when used with certain implantable pumps. Please consult manufacturer’s manual for specific recommendations.
Delivery Regimen:
LIORESAL INTRATHECAL is most often administered in a continuous infusion mode immediately following implant. For those patients implanted with programmable pumps who have achieved relatively satisfactory control on continuous infusion, further benefit may be attained using more complex schedules of LIORESAL INTRATHECAL delivery. For example, patients who have increased spasms at night may require a 20% increase in their hourly infusion rate. Changes in flow rate should be programmed to start two hours before the time of desired clinical effect.
How Supplied
LIORESAL INTRATHECAL (baclofen injection) is packaged in single use ampules containing 0.05 mg/1 mL (50 mcg/mL), 10 mg/20 mL (500 mcg/mL), 10 mg/5 mL (2000 mcg/mL), or 40 mg/20 mL (2000 mcg/mL) supplied as follows:
Screening dose (Model 8563s): five ampules each containing 0.05 mg/1 mL (50 mcg/mL)
(NDC 70121-2496-5).
LIORESAL INTRATHECAL (baclofen injection) Refill Kits. Each refill kit includes the indicated amount of LIORESAL INTRATHECAL, a drug preparation kit, a pump refill kit with accessories that are compatible with Medtronic SynchroMed® Infusion Systems, and associated instructions.
Model 8561: one ampule containing 10 mg/20 mL (500 mcg/mL)
(NDC 70121-2501-1).
Model 8562: two ampules, each contains 10 mg/5 mL (2000 mcg/mL)
(NDC 70121-2502-2).
Model 8564: one ampule containing 40 mg/20 mL (2000 mcg/mL)
(NDC 70121-2503-1).
Model 8565: two ampules, each contains 10 mg/20 mL (500 mcg/mL)
(NDC 70121-2504-2).
Model 8566: two ampules, each contains 40 mg/20 mL (2000 mcg/mL)
(NDC 70121-2505-2).
Storage
Does not require refrigeration. Do not store above 86° F (30° C). Do not freeze. Do not heat sterilize.
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