Baclofen: A Historical Journey and Modern Applications in Spasticity Management

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History of Baclofen

Early Uses and Discoveries

The use of baclofen dates back to the 1920s when it was initially explored as a potential antiepileptic drug. Researchers discovered that it was also safe and effective for reducing spasticity. However, its true potential was realized in the 1980s when it was found to be more effective when delivered directly to the central nervous system.

Key Research Milestones

  • 1981: Dr. Tony Yaksh studied the analgesic effects of baclofen when administered intraspinally to primates.
  • 1984: Richard Penn, MD, conducted the first study of intraspinal administration of baclofen for hypertonicity in rabbits and later expanded his research to humans.
  • Early 1990s: Baclofen gained FDA approval for intrathecal administration.
  • 1992: Baclofen was approved for administration through implantable infusion pumps.

Current Uses

Baclofen is widely used to manage spasticity in adults and children with conditions such as spinal cord injuries, cerebral palsy, and multiple sclerosis. Technological advancements have enabled medical professionals to minimize the severe side effects of oral medication, achieving superior effects on spasticity through intrathecal administration.

About Baclofen

Mechanism of Action

Baclofen is structurally related to gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter. It acts on GABA-B receptors in the brainstem and the dorsal horn of the spinal cord, reducing muscle tone by suppressing the release of excitatory neurotransmitters.

Experience at Hartley Medical

Hartley Medical has extensive experience with baclofen and its intraspinal application, having quantitatively analyzed it for over twelve years. Treatment with baclofen must consider its small therapeutic window and significant withdrawal issues, which require careful management.

Compounding and Stability

Baclofen can be compounded in concentrations exceeding 4,000 mcg/ml. However, some reports suggest instability at concentrations above 2,000 mcg/ml. Hartley Medical possesses expansive knowledge of baclofen for intraspinal use and pump administration, particularly concerning storage within an implantable pump for 60 to 90 days.

Contact Information

For further discussion on baclofen, please contact us at

Baclofen in Combination with Other Medications

Compatibility and Stability Studies

Baclofen can be safely compounded with various medications, including fentanyl, sufentanil, ziconotide, morphine, and hydromorphone. It has a good shelf life and sustained stability within an implantable pump.

  • Study by Donald A. Godwin, PhD, Nae-Hwa Kim, and Robert Zuniga, MD (2001): Published in Hospital Pharmacy, this study showed that baclofen and clonidine remained stable in borosilicate test tubes stored at 37 degrees Celsius for 10 weeks.
  • Study in the International Journal of Pharmaceutics: This research determined that baclofen and morphine maintained their chemical structure when introduced into an implantable device and stored at body temperature for 30 days.

Additive Effects and Potential Combinations

  • Study in Pain Physician (March/April 2008): Preclinical data in rats revealed that when baclofen is co-administered with morphine or fentanyl, it exhibits additive nociceptive effects and significantly suppresses retching and vomiting induced by morphine. It also inhibits place preference elicited by morphine or fentanyl. The study suggests that potential future combination products of morphine and baclofen ("morphlofen") may be of interest.


Baclofen remains a crucial drug for managing spasticity in various conditions, with its applications expanding thanks to continuous research and technological advancements. At Hartley Medical, we are committed to providing high-quality compounded medications and are at the forefront of innovative treatments for spasticity.

For more drug reviews and insights, visit Hartley Medical's Knowledge Center.