Spasticity Management Clinic
Baclofen Prescribing Information for Physicians

Indication:  There is Level 2 evidence (from small randomized clinical trials) for the effectiveness of oral baclofen in reducing spastic hypertonia in adolescents and adults with cerebral palsy, spinal cord injury and traumatic brain injury.  Baclofen has not been approved by the FDA for oral use in children under twelve, but, like many other drugs, it has been used for many years in children. A multicenter study to obtain FDA approval is recruiting participants.

Pharmacology:  Baclofen is a gamma-amino butyric acid (GABA) agonist that inhibits the activity of motor neurons in the anterior horn of the spinal cord and other sites in the central nervous system.  

Usual Dose:  Can be taken with food
For children under 20 kg
2.5 mg qAM x 3 d
2.5 mg BID  x 3 d
2.5 mg TID  x 3 d
5 mg TID  x 2 - 3 weeks	For children at least 20 kg
  5 mg qAM x 3 d
  5 mg BID  x 3 d
  5 mg TID  x 3 d
10 mg TID  x 2 - 3 weeks
Increase further if desired
Note: Adolescents and children over 30 kilograms in weight can start at 5 mg TID	

Therapeutic effect or side effects may be encountered at doses as low as 5 mg BID.  Titrate as high as 20 mg TID.  The package insert indicates a maximum dose of 80mg/day (20 mg 4 times daily).  Higher doses may be warranted in the rare adolescent who shows no or slight therapeutic response to usual doses but experiences no side effects.  Serum levels can be measured but are not useful in clinical practice at the present time.

Formulation:  Baclofen comes in 10 mg and 20 mg tablets that can be cut in half.  Crushed tablets can be suspended in liquid and administered by mouth or gastrostomy.  A pharmacist can prepare an extemporaneous suspension that is reasonably stable (see over).

Side Effects:
Drowsiness/dizziness/nausea/constipation
Decreased motor control/swallowing problems
Decreased seizure threshold but most children on anticonvulsants do not experience significant increases in seizure activity on baclofen.  No interference with anticonvulsant levels is seen.
Confusion/headache/insomnia/agitation and other neuropsychiatric symptoms occur less commonly.
No risk of liver or kidney injury.

Drug Interactions:  Baclofen has a synergistic effect on tone when combined with a benzodiazepine (diazepam, chlorazepam, midazolam, etc).  This effect is clinically useful in some patients but may be a reason for caution/dose reduction when starting baclofen for a child already on a benzodiazepine.

Monitoring Effect on Muscle Tone:  Ask the child, parents and the child’s physical therapist to monitor tone, comfort, positioning, mobility and other specific predetermined aspects of each child’s condition for a brief baseline period and at appropriate intervals.  Benefit should be apparent within two to four weeks after reaching a stable therapeutic dose.

Stopping Baclofen:  When reducing or discontinuing a full therapeutic regimen of baclofen, the dose should be tapered over one to three weeks to avoid the risk of irritability, insomnia or hallucinations. Families should be cautioned to keep the prescription filled properly to avoid running out of baclofen.  

Disclaimer:  This physicians’ information sheet was developed through the efforts of Seattle Children’s Hospital and its physicians in the interest of advancing pediatric health care.  Drug information is constantly evolving because of ongoing research and clinical experience and is often subject to interpretation.  While care has been taken to ensure the accuracy of the information presented, the reader is advised that the authors, editors, reviewers, contributors and publishers cannot be responsible for the continued currency of the information or for any errors or omissions or for any consequences arising therefrom.  Readers are advised that decisions regarding drug therapy must be based on the independent judgment of the clinician, changing information about a drug, and changing medical practices.  The editors are not responsible for any inaccuracy of quotation or for any false or misleading implication that may arise due to the text or formulas as used or due to the quotation of revisions no longer official.
Procedures for compounding baclofen 5 mg/ml oral suspension

1.  Count out #30 20 mg baclofen tablets, and place the tablets in a mortar.
2.  Comminute the tablets to a fine powder.
3.  Add 12 ml of distilled water and mix to a uniform paste.
4.  Add 24 mml Ora-Plus and mix thoroughly.
5.  Mix in 20 to 40 ml cherry syrup until the mixture can be poured.
6.  Transfer the contents of the mortar to the calibrated bottle.
7.   Rinse mortar with cherry syrup and add to bottle.
6.  Add enough cherry syrup to bring the final volume to 120 ml.
7.  Label the bottle “Shake Well Before Using” and “Protect From Light”.
8.  Label the bottle with an expiration date of 35 days.

 Other vehicles that may be used include:
1:1 mixture of Ora-Sweet® and Ora Plus®
1:1 mixture of Ora-Sweet SF® and Ora Plus®
1:4 mixture of cherry syrup and simple syrup

Johnson KCE, Hart SM. Stability of an extemporaneously compounded baclofen oral liquid. Am J Hosp Pharm1993; 50:2353-2355.
Allen LV, Erickson MA, Stability of baclofen, captopril, diltiazem hydrochloride, dipyridamole and flecainide acetate in extemporaneously compounded oral liquids.  Am J Health-Syst Pharm 1996;53:2179-84.