Studies Show Advantages of Topical Analgesics in Chronic Pain Management

Allison Inserro

Topical analgesics were safe and effective at reducing chronic pain, according to a study that also looked at whether or not a subgroup of patients were able to stop using opioids a few months after treatment.

About 50% of those patients were able to discontinue use of opioids after 3 or 6 months of treatment, the study authors said in a statement.

The main study of 631 adult patients looked at 4 classes of prescription compounds. The compounds consisted mainly of:
Pain complaints included arthritis, neuropathy or radiculopathy, myofascial or musculoskeletal pain, tendonitis, or some other type of pain. Main study endpoints included changes in pain severity and interference, as well as use of other pain medicines at the same time.

Study results from the OPERA trial (Optimizing Patient Experience and Response to Topical Analgesics) were published in October 2017 in the Journal of Pain Research.1 The subgroup results were published last week in the Journal of Postgraduate Medicine.2

Topical treatments for pain are being studied as an alternative to opioids. Unlike opioids, topical treatments are site specific and do not have systemic side effects, which may include opioid-induced constipation, sedation, physical dependence, nausea, dizziness, and respiratory depression. Last year, there were 64,000 drug overdose deaths, with 500000 linked to opioids, the federal government said recently.

In the main trial, an unmatched intervention group (unmatched-IG) included 631 patients who completed baseline and 3-month follow-up surveys (3-month unmatched-IG) and 158 who completed baseline and 6-month follow-up assessments (6-month unmatched-IG).

Baseline and 3-month follow-up data were provided by 76 unmatched controls and 76 matched controls (3-month unmatched-CG and matched-CG); 51 unmatched and 36 matched patients in the control group completed baseline and 6-month follow-up surveys (6-month unmatched-CG and matched-CG).

There were statistically significant decreases in mean pain severity and interference scores within the 3- and 6-month unmatched-IG (all P <.001). Significantly greater decreases in pain severity and interference scores were shown for the 3- and 6-month unmatched-IG versus unmatched-CG (all P <.001), with similar results when the 3- and 6-month matched-IG and matched-CG were compared.

A higher percentage of patients in the 3- and 6-month unmatched-IG and matched-IG cut back on use of concurrent pain medications (all P <.001). Significantly higher percentages of the unmatched-CG and matched-CG escalated medication use. Side effects were reported by <1% of the unmatched-IG.

Since this was a prospective exploratory study, randomized controlled trials are needed to confirm the results, the authors said.

In the subgroup results of 121 chronic pain patients who were using opioids at study enrollment, 49% in the 3-month group and 56% in the 6-month group reported they had completely ended use of opioids. In addition, 30% of patients reported that they were no longer taking any pain medication. Concurrent medications decreased by 65% after 3 months, and 74% after 6 months.

1. Gudin JA, Brennan MJ, et al. Changes in pain and concurrent pain medication use following compounded topical analgesic treatment for chronic pain: 3- and 6-month follow-up results from the prospective, observational Optimizing Patient Experience and Response to Topical Analgesics study. J Pain Res. 2017; (10)2341-2354. doi: 10.2147/JPR.S143513.

2. Gudin JA, Brennan MJ, et al. Reduction of opioid use and improvement in chronic pain in opioid-experienced patients after topical analgesic treatment: an exploratory analysis. Published online December 22, 2017. Journal of Postgraduate Medicine. doi: 10.1080/00325481.2018.1414551.

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