Complex regional pain syndrome (CRPS; previously known as Reflex Sympathetic Dystrophy) can be treated with NSAIDs; beta-2 agonists, such as clonidine; tricyclic antidepressants; anticonvulsants; local anesthetics; or NMDA antagonists, such as ketamine. It is critical to consider these medications in patients with CRPS, because there are no drugs approved specifically to treat CRPS. Patients with CRPS might require trials of several medications before adequate pain control is achieved.
In a case study of a 42-year-old male diagnosed with CRPS, who was previously treated with high-dose gabapentin, pregabalin, tramadol, and NSAIDs without benefit, topical amitriptyline was chosen as the main therapeutic regimen after his clinical response to oral amitriptyline 25 mg. Amitriptyline 5% cream applied three times a day resulted in 30% reduction in pain after one month. Topical ketamine 10% and dimethyl sulfoxide (as a penetration enhancer) were added to the preparation. After eight months of therapy, applying the cream only once daily, his pain almost disappeared, according to the patient.
The quotes and recommendations represent a synopsis of a comprehensive CME article “Use of Topical Pain Medications in the Treatment of Various Pain Syndromes” written by Sahar Z. Swidan, PharmD (Adjunct Clinical Associate Professor of Pharmacy, University of Michigan College of Pharmacy, and Chief Executive Officer of Pharmacy Solutions) and Hagar A. Mohamed, MS (Pharmacist and Researcher, Ann Arbor, Michigan) and published in Topics in Pain Management, February, 2016. 31(7): 1-10.