Background: Federal health system programs, including TRICARE for military personnel, spent $259 million in 2013 and $746 million in 2014 for compounded analgesic medications despite a dearth of efficacy data. The purpose of this trial was to evaluate the efficacy and functional impact of this class of medications for chronic localized pain.
Study design: Randomized, double-blind, parallel trial.
Setting: Walter Reed National Military Medical Center.
Synopsis: A total of 339 patients with at least mild, chronic localized pain were allocated to three subgroups of 133 patients based on pain type; neuropathic, nociceptive, or mixed pain. The patients in the neuropathic pain arm received a compounded formulation containing 10% ketamine, 6% gabapentin, 0.2% clonidine, and 2% lidocaine; in the nociceptive pain arm, a formulation containing 10% ketoprofen, 2% baclofen, 2% cyclobenzaprine, and 2% lidocaine; and in the mixed pain arm, a formulation containing 10% ketamine, 6% gabapentin, 3% diclofenac, 2% baclofen, 2% cyclobenzaprine, and 2% lidocaine. Half of the patients in each subgroup received the compounded formulation and the other half received placebo.
The primary outcome was the average pain score at 1 month follow-up, based on self-recorded arithmetic mean pain scores in the preceding week. Secondary outcomes included mean worst pain over the past week, functional improvement (assessed by validated Short-Form 36 Health Survey scores), and satisfaction (measured on a 1 to 5 Likert scale) with the individual treatment regimen.
Patients had small improvements in average pain scores at 1 month in the compounded formulation and placebo subgroups in all pain type categories. No significant differences were noted in the average pain scores compared to baseline, functional improvement or satisfaction in the compounded formulation and placebo groups of the total cohort or in any of the subgroups.
Bottom line: Compounded topical analgesics are costly and ineffective in the treatment of all types of chronic localized pain.
Citation: Brutcher RE et al. Compounded topical pain creams to treat localized chronic pain. Ann Intern Med. 2019;170(5):309-18.
Dr. Lambert is a hospital medicine clinician and addiction medicine specialist in the division of hospital medicine at Massachusetts General Hospital.