rigin: evidence supporting the efficacy of lioresal intrathecal was obtained in randomized, controlled investigations that compared the effects of either a single intrathecal dose or a three day intrathecal infusion of lioresal intrathecal to placebo in patients with severe spasticity and spasms due to either spinal cord trauma or multiple sclerosis. lioresal intrathecal was superior to placebo on both principal outcome measures employed: change from baseline in the ashworth rating of spasticity and the frequency of spasms. spasticity of cerebral origin: the efficacy of lioresal intrathecal was investigated in three controlled clinical trials; two enrolled patients with cerebral palsy and one enrolled patients with spasticity due to previous brain injury. the first study, a randomized controlled cross-over trial of 51 patients with cerebral palsy, provided strong, statistically significant results; lioresal intrathecal was superior to placebo in reducing spasticity as measured by the ashworth scale. a second cross-over study was conducted in 11 patients with spasticity arising from brain injury. despite the small sample size, the study yielded a nearly significant test statistic (p= 0.066) and provided directionally favorable results. the last study, however, did not provide data that could be reliably analyzed. lioresal intrathecal therapy may be considered an alternative to destructive neurosurgical procedures. prior to implantation of a device for chronic intrathecal infusion of lioresal intrathecal, patients must show a response to lioresal intrathecal in a screening trial (see dosage and administration ).

d 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. overdose: signs of overdose may appear suddenly or insidiously. acute massive overdose may present as coma. less sudden and/or less severe forms of overdose may present with signs of drowsiness, lightheadedness, dizziness, somnolence, respiratory depression, seizures, rostral progression of hypotonia and loss of consciousness progressing to coma. should overdose appear likely, the patient should be taken immediately to a hospital for assessment and emptying of the pump reservoir. in cases reported to date, overdose has generally been related to pump malfunction, inadvertent subcutaneous injection, or dosing error. (see drug overdose symptoms and treatment. ) extreme caution must be used when filling an fda approved implantable pump. such pumps should only be refilled through the reservoir refill septum. inadvertent injection into the subcutaneous tissue can occur if the reservoir refill septum is not properly accessed. some pumps are also equipped with a catheter access port that allows direct access to the intrathecal catheter. direct injection into this catheter access port or inadvertent injection into the subcutaneous tissue may cause a life-threatening overdose. withdrawal: abrupt withdrawal of intrathecal baclofen, regardless of the cause, has resulted in sequelae that included high fever, altered mental status, exaggerated rebound spasticity and muscle rigidity that in rare cases progressed to rhabdomyolysis, multiple organ-system failure, and death. in the first 9 years of post-marketing experience, 27 cases of withdrawal temporally related to the cessation of baclofen therapy were reported; six patients died. in most cases, symptoms of withdrawal appeared within hours to a few days following interruption of baclofen therapy. common reasons for abrupt interruption of intrathecal baclofen therapy included malfunction of the catheter (especially disconnection), low volume in the pump reservoir, and end of pump battery life; human error may have played a causal or contributing role in some cases. cases of intrathecal mass at the tip of the implanted catheter leading to withdrawal symptoms have also been reported, most of them involving pharmacy compounded analgesic admixtures (see precautions ). prevention of abrupt discontinuation of intrathecal baclofen requires careful attention to programming and monitoring of the infusion system, refill scheduling and procedures, and pump alarms. patients and caregivers should be advised of the importance of keeping scheduled refill visits and should be educated on the early symptoms of baclofen withdrawal. all patients receiving intrathecal baclofen therapy are potentially at risk for withdrawal. early symptoms of baclofen withdrawal may include return of baseline spasticity, pruritus, hypotension, and paresthesias. priapism may develop or recur if treatment with intrathecal baclofen is interrupted. some clinical characteristics of the advanced intrathecal baclofen withdrawal syndrome may resemble autonomic dysreflexia, infection (sepsis), malignant hyperthermia, neuroleptic-malignant syndrome, or other conditions associated with a hypermetabolic state or widespread rhabdomyolysis. rapid, accurate diagnosis and treatment in an emergency-room or intensive-care setting are important in order to prevent the potentially life-threatening central nervous system and systemic effects of intrathecal baclofen withdrawal. the suggested treatment for intrathecal baclofen withdrawal is the restoration of intrathecal baclofen at or near the same dosage as before therapy was interrupted. however, if restoration of intrathecal delivery is delayed, treatment with gaba-ergic agonist drugs such as oral or enteral baclofen, or oral, enteral, or intravenous benzodiazepines may prevent potentially fatal sequelae. oral or enteral baclofen alone should not be relied upon to halt the progression of intrathecal baclofen withdrawal. seizures have been reported during overdose and with withdrawal from lioresal intrathecal as well as in patients maintained on therapeutic doses of lioresal intrathecal. fatalities: spasticity of spinal cord origin: there were 16 deaths reported among the 576 u.s. patients treated with lioresal intrathecal (baclofen injection) in pre- and post- marketing studies evaluated as of december 1992. because these patients were treated under uncontrolled clinical settings, it is impossible to determine definitively what role, if any, lioresal intrathecal played in their deaths. as a group, the patients who died were relatively young (mean age was 47 with a range from 25 to 63), but the majority suffered from severe spasticity of many years duration, were nonambulatory, had various medical complications such as pneumonia, urinary tract infections, and decubiti, and/or had received multiple concomitant medications. a case-by-case review of the clinical course of the 16 patients who died failed to reveal any unique signs, symptoms, or laboratory results that would suggest that treatment with lioresal intrathecal caused their deaths. two patients, however, did suffer sudden and unexpected death within 2 weeks of pump implantation and one patient died unexpectedly after screening. one patient, a 44 year old male with ms, died in hospital on the second day following pump implantation. an autopsy demonstrated severe fibrosis of the coronary conduction system. a second patient, a 52 year old woman with ms and a history of an inferior wall myocardial infarction, was found dead in bed 12 days after pump implantation, 2 hours after having had documented normal vital signs. an autopsy revealed pulmonary congestion and bilateral pleural effusions. it is impossible to determine whether lioresal intrathecal contributed to these deaths. the third patient underwent three baclofen screening trials. his medical history included sci, aspiration pneumonia, septic shock, disseminated intravascular coagulopathy, severe metabolic acidosis, hepatic toxicity, and status epilepticus. twelve days after screening (he was not implanted), he again experienced status epilepticus with subsequent significant neurological deterioration. based upon prior instruction, extraordinary resuscitative measures were not pursued and the patient died. spasticity of cerebral origin: there were three deaths occurring among the 211 patients treated with lioresal intrathecal in pre- marketing studies as of march 1996. these deaths were not attributed to the therapy. overinfusion: delivery of more drug volume than the programmed rate (overinfusion) can result in unexpected overdose, or withdrawal caused by early emptying of the pump reservoir. refer to the manufacturer's pump manual and instructions for refilling the reservoir.

nto the intrathecal space by barbotage over a period of not less than one minute. the patient is observed over the ensuing 4 to 8 hours. a positive response consists of a significant decrease in muscle tone and/or frequency and/or severity of spasms. if the initial response is less than desired, a second bolus injection may be administered 24 hours after the first. the second screening bolus dose consists of 75 micrograms in 1.5 milliliters. again, the patient should be observed for an interval of 4 to 8 hours. if the response is still inadequate, a final bolus screening dose of 100 micrograms in 2 milliliters may be administered 24 hours later. pediatric patients: the starting screening dose for pediatric patients is the same as in adult patients, i.e., 50 mcg. however, for very small patients, a screening dose of 25 mcg may be tried first. patients who do not respond to a 100 mcg intrathecal bolus should not be considered candidates for an implanted pump for chronic infusion. post-implant dose titration period: to determine the initial total daily dose of lioresal intrathecal following implant, the screening dose that gave a positive effect should be doubled and administered over a 24-hour period, unless the efficacy of the bolus dose was maintained for more than 8 hours, in which case the starting daily dose should be the screening dose delivered over a 24-hour period. no dose increases should be given in the first 24 hours (i.e., until the steady state is achieved). adult patients with spasticity of spinal cord origin: after the first 24 hours, for adult patients, the daily dosage should be increased slowly by 10-30% increments and only once every 24 hours, until the desired clinical effect is achieved. adult patients with spasticity of cerebral origin: after the first 24 hours, the daily dose should be increased slowly by 5-15% only once every 24 hours, until the desired clinical effect is achieved. pediatric patients: after the first 24 hours, the daily dose should be increased slowly by 5-15% only once every 24 hours, until the desired clinical effect is achieved. if there is not a substantive clinical response to increases in the daily dose, check for proper pump function and catheter patency. patients must be monitored closely in a fully equipped and staffed environment during the screening phase and dose-titration period immediately following implant. resuscitative equipment should be immediately available for use in case of life-threatening or intolerable side effects. maintenance therapy: spasticity of spinal cord origin patients: the clinical goal is to maintain muscle tone as close to normal as possible, and to minimize the frequency and severity of spasms to the extent possible, without inducing intolerable side effects. very often, the maintenance dose needs to be adjusted during the first few months of therapy while patients adjust to changes in life style due to the alleviation of spasticity. during periodic refills of the pump, the daily dose may be increased by 10-40%, but no more than 40%, to maintain adequate symptom control. the daily dose may be reduced by 10-20% if patients experience side effects. most patients require gradual increases in dose over time to maintain optimal response during chronic therapy. a sudden large requirement for dose escalation suggests a catheter complication (i.e., catheter kink or dislodgement). maintenance dosage for long term continuous infusion of lioresal intrathecal (baclofen injection) has ranged from 12 mcg/day to 2003 mcg/ day, with most patients adequately maintained on 300 micrograms to 800 micrograms per day. there is limited experience with daily doses greater than 1000 mcg/day. determination of the optimal lioresal intrathecal dose requires individual titration. the lowest dose with an optimal response should be used. spasticity of cerebral origin patients: the clinical goal is to maintain muscle tone as close to normal as possible and to minimize the frequency and severity of spasms to the extent possible, without inducing intolerable side effects, or to titrate the dose to the desired degree of muscle tone for optimal functions. very often the maintenance dose needs to be adjusted during the first few months of therapy while patients adjust to changes in life style due to the alleviation of spasticity. during periodic refills of the pump, the daily dose may be increased by 5-20%, but no more than 20%, to maintain adequate symptom control. the daily dose may be reduced by 10-20% if patients experience side effects. many patients require gradual increases in dose over time to maintain optimal response during chronic therapy. a sudden large requirement for dose escalation suggests a catheter complication (i.e., catheter kink or dislodgement). maintenance dosage for long term continuous infusion of lioresal intrathecal (baclofen injection) has ranged from 22 mcg/ day to 1400 mcg/ day, with most patients adequately maintained on 90 micrograms to 703 micrograms per day. in clinical trials, only 3 of 150 patients required daily doses greater than 1000 mcg/ day. pediatric patients: use same dosing recommendations for patients with spasticity of cerebral origin. pediatric patients under 12 years seemed to require a lower daily dose in clinical trials. average daily dose for patients under 12 years was 274 mcg/ day, with a range of 24 to 1199 mcg/ day. dosage requirement for pediatric patients over 12 years does not seem to be different from that of adult patients. determination of the optimal lioresal intrathecal dose requires individual titration. the lowest dose with an optimal response should be used. potential need for dose adjustments in chronic use: during long term treatment, approximately 5% (28/627) of patients become refractory to increasing doses. there is not sufficient experience to make firm recommendations for tolerance treatment; however, this "tolerance" has been treated on occasion, in hospital, by a "drug holiday" consisting of the gradual reduction of lioresal intrathecal over a 2 to 4 week period and switching to alternative methods of spasticity management. after the "drug holiday," lioresal intrathecal may be restarted at the initial continuous infusion dose. 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. preparation instruction: screening use the 1 ml screening ampule only (50 mcg/ml) for bolus injection into the subarachnoid space. for a 50 mcg bolus dose, use 1 ml of the screening ampule. use 1.5 ml of 50 mcg/ml baclofen injection for a 75 mcg bolus dose. for the maximum screening dose of 100 mcg, use 2 ml of 50 mcg/ml baclofen injection (2 screening ampules). maintenance for patients who require concentrations other than 500 mcg/ml or 2000 mcg/ml, lioresal intrathecal must be diluted. lioresal intrathecal must be diluted with sterile preservative free sodium chloride for injection, u.s.p. 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.

all were subsequently restarted and were not, therefore, considered to be true discontinuations. fatalities — see warnings . incidence in controlled trials — experience with lioresal intrathecal (baclofen injection) obtained in parallel, placebo-controlled, randomized studies provides only a limited basis for estimating the incidence of adverse events because the studies were of very brief duration (up to three days of infusion) and involved only a total of 63 patients. the following events occurred among the 31 patients receiving lioresal intrathecal (baclofen injection) in two randomized, placebo-controlled trials: hypotension (2), dizziness (2), headache (2), dyspnea (1). no adverse events were reported among the 32 patients receiving placebo in these studies. events observed during the pre- and post-marketing evaluation of lioresal intrathecal — adverse events associated with the use of lioresal intrathecal reflect experience gained with 576 patients followed prospectively in the united states. they received lioresal intrathecal for periods of one day (screening) (n = 576) to over eight years (maintenance) (n = 10). the usual screening bolus dose administered prior to pump implantation in these studies was typically 50 mcg. the maintenance dose ranged from 12 mcg to 2003 mcg per day. because of the open, uncontrolled nature of the experience, a causal linkage between events observed and the administration of lioresal intrathecal cannot be reliably assessed in many cases and many of the adverse events reported are known to occur in association with the underlying conditions being treated. nonetheless, many of the more commonly reported reactions— hypotonia, somnolence, dizziness, paresthesia, nausea/vomiting and headache— appear clearly drug-related. adverse experiences reported during all u.s. studies (both controlled and uncontrolled) are shown in the following table. eight of 474 patients who received chronic infusion via implanted pumps had adverse experiences which led to a discontinuation of long term treatment in the pre- and post-marketing studies. incidence of most frequent (≥1%) adverse events in patients with spasticity of spinal origin in prospectively monitored clinical trials percent of patients reporting events n = 576 screening following administration of test bolus percent n = 474 titration two month period following implant percent n = 430 maintenance beyond two months following implant percent adverse event n= total number of patients entering each period %=% of patients evaluated hypotonia 5.4 13.5 25.3 somnolence 5.7 5.9 20.9 dizziness 1.7 1.9 7.9 paresthesia 2.4 2.1 6.7 nausea and vomiting 1.6 2.3 5.6 headache 1.6 2.5 5.1 constipation 0.2 1.5 5.1 convulsion 0.5 1.3 4.7 urinary retention 0.7 1.7 1.9 dry mouth 0.2 0.4 3.3 accidental injury 0.0 0.2 3.5 asthenia 0.7 1.3 1.4 confusion 0.5 0.6 2.3 death 0.2 0.4 3.0 pain 0.0 0.6 3.0 speech disorder 0.0 0.2 3.5 hypotension 1.0 0.2 1.9 ambylopia 0.5 0.2 2.3 diarrhea 0.0 0.8 2.3 hypoventilation 0.2 0.8 2.1 coma 0.0 1.5 0.9 impotence 0.2 0.4 1.6 peripheral edema 0.0 0.0 2.3 urinary incontinence 0.0 0.8 1.4 insomnia 0.0 0.4 1.6 anxiety 0.2 0.4 0.9 depression 0.0 0.0 1.6 dyspnea 0.3 0.0 1.2 fever 0.5 0.2 0.7 pneumonia 0.2 0.2 1.2 urinary frequency 0.0 0.6 0.9 urticaria 0.2 0.2 1.2 anorexia 0.0 0.4 0.9 diplopia 0.0 0.4 0.9 dysautonomia 0.2 0.2 0.9 hallucinations 0.3 0.4 0.5 hypertension 0.2 0.6 0.5 in addition to the more common (1% or more) adverse events reported in the prospectively followed 576 domestic patients in pre- and post-marketing studies, experience from an additional 194 patients exposed to lioresal intrathecal (baclofen injection) from foreign studies has been reported. the following adverse events, not described in the table, and arranged in decreasing order of frequency, and classified by body system, were reported: nervous system: abnormal gait, thinking abnormal, tremor, amnesia, twitching, vasodilitation, cerebrovascular accident, nystagmus, personality disorder, psychotic depression, cerebral ischemia, emotional lability, euphoria, hypertonia, ileus, drug dependence, incoordination, paranoid reaction and ptosis. digestive system: flatulence, dysphagia, dyspepsia and gastroenteritis. cardiovascular : postural hypotension, bradycardia, palpitations, syncope, arrhythmia ventricular, deep thrombophlebitis, pallor and tachycardia. respiratory : respiratory disorder, aspiration pneumonia, hyperventilation, pulmonary embolus and rhinitis. urogenital: hematuria and kidney failure. skin and appendages: alopecia and sweating. metabolic and nutritional disorders: weight loss, albuminuria, dehydration and hyperglycemia. special senses: abnormal vision, abnormality of accommodation, photophobia, taste loss and tinnitus. body as a whole: suicide, lack of drug effect, abdominal pain, hypothermia, neck rigidity, chest pain, chills, face edema, flu syndrome and overdose. hemic and lymphatic system: anemia. spasticity of cerebral origin — clinical studies: commonly observed — in pre-marketing clinical trials, the most commonly observed adverse events associated with use of lioresal intrathecal (baclofen injection) which were not seen at an equivalent incidence among placebo-treated patients included: agitation, constipation, somnolence, leukocytosis, chills, urinary retention and hypotonia. associated with discontinuation of treatment — nine of 211 patients receiving lioresal intrathecal in pre-marketing clinical studies in the u.s. discontinued long term infusion due to adverse events associated with intrathecal therapy. the nine adverse events leading to discontinuation were: infection (3), csf leaks (2), meningitis (2), drainage (1), and unmanageable trunk control (1). fatalities — three deaths, none of which were attributed to lioresal intrathecal, were reported in patients in clinical trials involving patients with spasticity of cerebral origin. see warnings on other deaths reported in spinal spasticity patients. incidence in controlled trials — experience with lioresal intrathecal (baclofen injection) obtained in parallel, placebo-controlled, randomized studies provides only a limited basis for estimating the incidence of adverse events because the studies involved a total of 62 patients exposed to a single 50 mcg intrathecal bolus. the following events occurred among the 62 patients receiving lioresal intrathecal in two randomized, placebo-controlled trials involving cerebral palsy and head injury patients, respectively: agitation, constipation, somnolence, leukocytosis, nausea, vomiting, nystagmus, chills, urinary retention, and hypotonia. events observed during the pre-marketing evaluation of lioresal intrathecal — adverse events associated with the use of lioresal intrathecal reflect experience gained with a total of 211 u. s. patients with spasticity of cerebral origin, of whom 112 were pediatric patients (under age 16 at enrollment). they received lioresal intrathecal for periods of one day (screening) (n= 211) to 84 months (maintenance) (n= 1). the usual screening bolus dose administered prior to pump implantation in these studies was 50-75 mcg. the maintenance dose ranged from 22 mcg to 1400 mcg per day. doses used in this patient population for long term infusion are generally lower than those required for patients with spasticity of spinal cord origin. because of the open, uncontrolled nature of the experience, a causal linkage between events observed and the administration of lioresal intrathecal cannot be reliably assessed in many cases. nonetheless, many of the more commonly reported reactions— somnolence, dizziness, headache, nausea, hypotension, hypotonia and coma— appear clearly drug-related. the most frequent (≥1%) adverse events reported during all clinical trials are shown in the following table. nine patients discontinued long term treatment due to adverse events. incidence of most frequent (≥ 1%) adverse events in patients with spasticity of cerebral origin in prospectively monitored clinical trials percent of patients reporting events n = 211 screening following administration of test bolus percent n = 153 titration two month period following implant percent n = 150 maintenance beyond two months following implant percent adverse event n= total number of patients entering each period. 211 patients received drug; (1 of 212) received placebo only. hypotonia 2.4 14.4 34.7 somnolence 7.6 10.5 18.7 headache 6.6 7.8 10.7 nausea and vomiting 6.6 10.5 4.0 vomiting 6.2 8.5 4.0 urinary retention 0.9 6.5 8.0 convulsion 0.9 3.3 10.0 dizziness 2.4 2.6 8.0 nausea 1.4 3.3 7.3 hypoventilation 1.4 1.3 4.0 hypertonia 0.0 0.7 6.0 paresthesia 1.9 0.7 3.3 hypotension 1.9 0.7 2.0 increased salivation 0.0 2.6 2.7 back pain 0.9 0.7 2.0 constipation 0.5 1.3 2.0 pain 0.0 0.0 4.0 pruritus 0.0 0.0 4.0 diarrhea 0.5 0.7 2.0 peripheral edema 0.0 0.0 3.3 thinking abnormal 0.5 1.3 0.7 agitation 0.5 0.0 1.3 asthenia 0.0 0.0 2.0 chills 0.5 0.0 1.3 coma 0.5 0.0 1.3 dry mouth 0.5 0.0 1.3 pneumonia 0.0 0.0 2.0 speech disorder 0.5 0.7 0.7 tremor 0.5 0.0 1.3 urinary incontinence 0.0 0.0 2.0 urination impaired 0.0 0.0 2.0 the more common (1% or more) adverse events reported in the prospectively followed 211 patients exposed to lioresal intrathecal (baclofen injection) have been reported. in the total cohort, the following adverse events, not described in the table, and arranged in decreasing order of frequency, and classified by body system, were reported: nervous system: akathisia, ataxia, confusion, depression, opisthotonos, amnesia, anxiety, hallucinations, hysteria, insomnia, nystagmus, personality disorder, reflexes decreased, and vasodilitation. digestive system: dysphagia, fecal incontinence, gastrointestinal hemorrhage and tongue disorder. cardiovascular: bradycardia. respiratory : apnea, dyspnea and hyperventilation. urogenital : abnormal ejaculation, kidney calculus, oliguria and vaginitis. skin and appendages: rash, sweating, alopecia, contact dermatitis and skin ulcer. special senses: abnormality of accommodation. body as a whole: death, fever, abdominal pain, carcinoma, malaise and hypothermia. hemic and lymphatic system: leukocytosis and petechial rash. postmarketing experience: the following adverse events have been reported during post-approval use of lioresal intrathecal. because these events are reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency. musculoskeletal: the onset of scoliosis or worsening of a pre-existing scoliosis has been reported. urogenital: sexual dysfunction in men and women, including decreased libido and orgasm dysfunction, have been reported. erectile dysfunction in men has also been reported. priapism has been reported following baclofen withdrawal.

ardiovascular depression. pharmacodynamics of lioresal intrathecal: intrathecal bolus: adult patients: the onset of action is generally one-half hour to one hour after an intrathecal bolus. peak spasmolytic effect is seen at approximately four hours after dosing and effects may last four to eight hours. onset, peak response, and duration of action may vary with individual patients depending on the dose and severity of symptoms. pediatric patients: the onset, peak response and duration of action is similar to those seen in adult patients. 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. continuous infusion: no additional information is available for pediatric patients. 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. intrathecal bolus: after a bolus lumbar injection of 50 or 100 mcg lioresal intrathecal in seven patients, the average csf elimination half-life was 1.51 hours over the first four hours and the average csf clearance was approximately 30 ml/hour. continuous infusion: the mean csf clearance for lioresal intrathecal (baclofen injection) was approximately 30 ml/hour in a study involving ten patients on continuous intrathecal infusion. concurrent plasma concentrations of baclofen during intrathecal administration are expected to be low (0- 5 ng/ml). limited pharmacokinetic data suggest that a lumbar-cisternal concentration gradient of about 4:1 is established along the neuroaxis during baclofen infusion. this is based upon simultaneous csf sampling via cisternal and lumbar tap in 5 patients receiving continuous baclofen infusion at the lumbar level at doses associated with therapeutic efficacy; the interpatient variability was great. the gradient was not altered by position. six pediatric patients (age 8-18 years) receiving continuous intrathecal baclofen infusion at doses of 77-400 mcg/day had plasma baclofen levels near or below 10 ng/ml.

ling via cisternal and lumbar tap in 5 patients receiving continuous baclofen infusion at the lumbar level at doses associated with therapeutic efficacy; the interpatient variability was great. the gradient was not altered by position. six pediatric patients (age 8-18 years) receiving continuous intrathecal baclofen infusion at doses of 77-400 mcg/day had plasma baclofen levels near or below 10 ng/ml.

cg/ml) (ndc 70257-563-02). storage does not require refrigeration. do not store above 86° f (30° c). do not freeze. do not heat sterilize.