CC13
Best Practices in Intrathecal Baclofen Therapy: Dosing and Long-Term Management
Objectives: To manage ITB dosing and therapy.
Methods: An expert panel consulted on best practices.
Results: Pump fill and drug delivery can be started intraoperatively. For new/replacement pumps, a pre-implant priming bolus should be given. After implant, priming of the catheter only will quickly advance the drug to the tip. Monitor the patient for at least 8 hrs.
Initiate with the 500 mcg/mL concentration to maximize dosing flexibility in the lower range. The starting daily dose should be twice the effective bolus screening dose, or the screening dose if the patient had a prolonged response (>8 hrs) or negative reactions. In tenuous cases, ITB can be started at a minimum rate and increased when the patient is stable.
Oral antispasmodics can be weaned, one drug at a time beginning with oral baclofen, after ITB begins. Oral baclofen doses can be decreased by 25%-50% at one time. Assess within 24 hrs of a dose change. Have oral baclofen available during titration and for management of ITB withdrawal.
For adults, daily dose increases may be 5%-15% once every 24 hrs for cerebral origin spasticity and 10%-30% once every 24 hrs for spinal origin spasticity. Daily dose increases can be 5%-15% once in 24 hrs for children. At lower doses, the higher increases are reasonable, but at higher doses an increase >20% may be excessive.
Assess response at least every 24 hrs for inpatients, who should receive intense, goal-directed rehabilitation. Outpatient adjustments can happen weekly, bi-weekly, or daily, depending on the patient’s ability to return. Step dosing (constant daily dosing for a set number of days before starting a higher continuous dose) can be used for patients who cannot return as often, but should be used cautiously in patients who use tone for function. Regular evaluation includes subjective, objective, and therapy goal measurements. Dosing options include simple continuous, variable 24-hr cycle, or regularly scheduled boluses.
Patients/caregivers should understand the treatment options, goals, and responsibilities, including follow-up and possible side effects (e.g., over- and under-dose). Low reservoir alarm dates and refill schedules should be written down, along with emergency contact information. A higher concentration can be used at refill to extend refill intervals. A bridge bolus must be programmed, after which the pump will automatically adjust the new flow rate. Time changes may affect flex dosing.
The SynchroMed II should be checked after MRI exposure. Pump replacement should be scheduled 3-6 mos before the replacement interval. In suspected catheter malfunctions, ITB should be weaned preoperatively. In verified malfunctions, the dose should be reduced to the starting dose before revision surgery.
Conclusions: ITB dosing is multistep and individualized.