Baclofen

What it is and how it works

Mechanism of Action 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.

Mechanism class: GABA A Agonists · GABA B Agonists

Indications

is indicated for use in the management of severe spasticity in adult and pediatric patients age 4 years and above. 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 GABLOFEN 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. GABLOFEN is intended for use by the intrathecal route in single bolus test doses (via spinal catheter or lumbar puncture) and, for chronic use, only with the Medtronic SynchroMed ® Programmable Pump or other pumps labeled for intrathecal administration of GABLOFEN . Prior to implantation of a device for chronic intrathecal infusion of GABLOFEN, patients must show a response to GABLOFEN in a screening trial .

Dosage and administration (summary)

Use Only in Medtronic SynchroMed ® Programmable Pump (or other pumps labeled for intrathecal administration of GABLOFEN) GABLOFEN is approved only for use with the Medtronic SynchroMed ® Programmable Pump or other pumps labeled for intrathecal administration of GABLOFEN. Refer to the manufacturer’s manual for specific instructions and precautions for programming the pump and/or refilling the reservoir. It is important to select the appropriate refill kit for the pump used to administer GABLOFEN. GABLOFEN is not to be compounded with other medications.

Contraindications

is contraindicated in patients with a hypersensitivity to baclofen. Do not use GABLOFEN for intravenous, intramuscular, subcutaneous or epidural administration. · Hypersensitivity to baclofen · Do not use GABLOFEN for intravenous, intramuscular, subcutaneous or epidural administration.

Warnings and precautions

Risk of Life-Threatening Overdose During Pump Refills Use extreme caution when filling the Medtronic SynchroMed ® Programmable Pump which is 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. Reservoir refilling must be performed by fully trained and qualified personnel following the directions provided by the pump manufacturer.

Pregnancy

Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of GABLOFEN in pregnant women. In animal studies, oral administration of baclofen to pregnant rats produced an increase in fetal malformations (see Data) .

Storage and supply

(baclofen injection) is a clear, colorless, sterile, pyrogenfree, isotonic solution supplied as follows: Package Type Strength (Concentration) NDC Single-dose syringe 50 mcg per mL 66794-151-01 10,000 mcg per 20 mL (500 mcg/mL) 66794-155-01 20,000 mcg per 20 mL (1,000 mcg/mL) 66794-156-01 40,000 mcg per 20 mL (2,000 mcg/mL) 66794-157-01 Single-dose…

Source: Baclofen Injection (Gablofen) — US FDA prescribing information, 2026-05-07, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.