Topical Ambroxol as a Possible Treatment for Complex Regional Pain Syndrome (CRPS)

What is complex regional pain syndrome?

Complex regional pain syndrome (CRPS), also called reflex sympathetic dystrophy syndrome (RSDS), is a type of chronic pain condition. It typically occurs after an injury and affects one limb (arm, leg, hand or foot). Though complex regional pain syndrome is not yet completely understood, it is believed that CRPS develops when the central or peripheral nervous system is damaged or malfunctions. It may also be caused by an immune system response.

What is ambroxol?

Ambroxol is a drug that is used in cough syrup and cold medications to loosen thickened mucus. It can also help relieve a sore throat when used topically in the form of a lozenge.

More recently, ambroxol has been studied for its pain-relieving capabilities beyond a sore throat. Initial studies have shown that topical ambroxol may relieve certain types of neuropathic pain, such as trigeminal neuralgia and fibromyalgia.

Topical ambroxol as a possible treatment for CRPS

Topical ambroxol is being researched as a potential treatment for complex regional pain syndrome (CRPS). Though ambroxol is not approved by the U.S. Food and Drug Administration (FDA) or Health Canada, it is available over the counter in some countries, including Germany.

Research

Initial research in Germany found that topical ambroxol relieved pain for some individuals with CRPS. It also improved or relieved other related symptoms, such as swelling, skin reddening, and warmth of the affected location.

Conclusion

The FDA has not approved any medications specifically for the treatment of CRPS; therefore, a potential treatment option is promising. However, the majority of studies involving topical ambroxol as treatment for neuropathic pain have been animal studies. Additional research and studies involving humans are needed to determine safety and efficacy as a CRPS treatment option.