Adult Dosing
Severe cerebral spasticity
- Screening phase:
- 50 mcg/mL IT by barbotage over 1 min; observe patients over the ensuing 4-8 hrs
- If initial response is less than desired, after 24 hrs administer 75 mcg IT over 1 min; observe for an interval of 4-8 hrs
- If the response is still inadequate, after 24 hrs administer 100 mcg IT over 1 min
- Do not consider patients not responding to a 100 mcg intrathecal bolus for an implanted pump for chronic infusion
- Dose titration:
- Initial total daily dose following implant: Double the screening dose that gave positive effect and administer over a 24-hr period, unless the efficacy of the bolus dose was maintained for more than 8 hrs, in which case the starting daily dose should be the screening dose delivered over a 24-hour period. Avoid increasing doses in the first 24 hrs
- Spasticity of cerebral origin: After first 24 hrs increase the daily dosage slowly by 5-15% increments only once q24 hrs, until the desired clinical effect is achieved
- Maintenance therapy:
- 90-703 mcg/day IT; titrate to desired effect by increasing the daily dose by 5- 20%, reduce daily dose by 10-20% if patients experience side effects
Severe spinal cord spasticity
- Screening phase:
- 50 mcg/mL IT by barbotage over 1 min;observe patients over the ensuing 4-8 hrs
- If initial response is less than desired, after 24 hrs administer 75 mcg IT over 1 min; observe for an interval of 4-8 hrs
- If the response is still inadequate, after 24 hrs administer 100 mcg IT over 1 min
- Do not consider patients not responding to a 100 mcg intrathecal bolus for an implanted pump for chronic infusion
- Dose titration:
- Initial total daily dose following implant: Double the screening dose that gave positive effect and administer over a 24-hr period, unless the efficacy of the bolus dose was maintained for more than 8 hrs, in which case the starting daily dose should be the screening dose delivered over a 24-hour period. Avoid increasing doses in the first 24 hrs
- Spasticity of spinal cord origin: After first 24 hrs increase the daily dosage slowly by 10-30% increments and only once q24 hrs, until the desired clinical effect is achieved
- Maintenance therapy:
- 300-800 mcg/day IT; titrate to desired effect by increasing the daily dose by 10- 40%, reduce daily dose by 10-20% if patients experience side effects
Note: Not recommended for intravenous, intramuscular, subcutaneous or epidural administration
Pediatric Dosing
Safety and effectiveness in pediatric patients < 4 yrs have not been established
Severe cerebral, spinal cord spasticity
>4 yrs
- Screening phase:
- 50 mcg/mL IT by barbotage over 1 min; observe patients over the ensuing 4-8 hrs
- If initial response is less than desired, after 24 hrs administer 75 mcg IT over 1 min; observe for an interval of 4-8 hrs
- If the response is still inadequate, after 24 hrs administer 100 mcg IT over 1 min
- Do not consider patients not responding to a 100 mcg intrathecal bolus for an implanted pump for chronic infusion
- May start with 25 mcg IT over 1 min in very small patients
- Dose titration:
- Initial total daily dose following implant: Double the screening dose that gave positive effect and administer over a 24-hr period, unless the efficacy of the bolus dose was maintained for more than 8 hrs, in which case the starting daily dose should be the screening dose delivered over a 24-hour period. Avoid increasing doses in the first 24 hrs
- After first 24 hrs, increase the daily dosage slowly by 5-15% increments only once q24 hrs, until the desired clinical effect is achieved
- Maintenance therapy:
- 90-703 mcg/day IT; titrate to desired effect by increasing the daily dose by 5- 20%, reduce daily dose by 10-20% if patients experience side effects
Note: Not recommended for intravenous, intramuscular, subcutaneous or epidural administration
[Outline]
- Abrupt withdrawal may cause high fever, altered mental status, exaggerated rebound spasticity, and muscle rigidity, which in rare cases may progress to rhabdomyolysis, multisystem failure, and death [US black box warning]
- Prevent abrupt withdrawal by programming and monitoring of the infusion system, refill scheduling and procedures, and pump alarms; advise patients and caregivers of the importance of keeping scheduled refill visits, and educate about early drug withdrawal symptoms; give special attention to patients at apparent risk (those with spinal cord injuries at T6 or above, communication problems, or history of withdrawal symptoms from oral or intrathecal baclofen) [US black box warning]
- Use in single bolus intrathecal injections and in implantable pumps approved by the FDA specifically for the intrathecal administration of baclofen
- Administer only under supervision of physicians who are trained and educated in chronic intrathecal infusion therapy as there is the possibility of potentially life-threatening CNS depression, cardiovascular collapse, and/or respiratory failure
- Perform reservoir refilling only under supervision of trained and qualified personnel following the manufacturer’s directions. Carefully calculate refill intervals in order to prevent reservoir depletion as this could result in the return of severe spasticity and withdrawal symptoms
- Advise extreme caution when filling an implantable pump equipped with an injection port that allows direct access to the intrathecal catheter as there is a possibility of life-threatening overdose
- Titrate doses carefully to maintain some degree of muscle tone and allow occasional spasms
- Gradually reduce the dosage if the drug is to be discontinued, except in overdose-related emergencies
- Do not implant the pump system until the patient’s response to bolus injection is adequately evaluated
- Resuscitative equipment should be available
- Refer pump manufacturer's manual for specific recommendations in case of children
- Adjust doses in patients according to spasticity origin
- Discontinue concomitant oral antispastics either prior to screening or following implant and initiation of chronic infusion to avoid possible overdose or adverse drug interactions; avoid abrupt reduction or discontinuation of oral anti-spasticity drugs
- Make sure that patients are infection-free prior to the screening trial because the presence of a systemic infection may interfere with an assessment of the patient’s response to bolus infusion
- Increase the dose gradually over time to maintain effectiveness; a sudden requirement for substantial dose escalation typically indicates a catheter complication
- Avoid bacterial contamination and serious infection by adapting strict aseptic techniques of filling
- Caution is advisable regarding the operation of automobiles or other dangerous machinery as drowsiness and CNS depression is caused by the drug
- Titrate doses carefully when spasticity is necessary to sustain upright posture and balance in locomotion or whenever spasticity is used to obtain optimal function and care
- Patients suffering from psychotic disorders, autonomic dysreflexia, schizophrenia, or confusional states should be treated cautiously
- Concurrent CNS depressant use, alcohol use should be avoided
Cautions: Use cautiously in
- Renal impairment
- Seizure disorder
- Psychiatric disorder
- CNS depression disorder
- Autonomic dysreflexia
Pregnancy Category:C
Breastfeeding: Limited information indicates that baclofen has low levels in milk; not expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. Monitor newborn infants for signs of sedation. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 15 November 2010). According to manufacturer's data, because there is an existing potential for serious adverse reactions in nursing infants from baclofen, a decision should be made whether to discontinue breastfeeding or to discontinue the drug, based on the importance of the drug to the mother.
