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CWCI Spotlights Low-Volume/High-Cost Dermatologicals, Opioids & Antidepressants

May 22, 2023 (5 min read)

Oakland, CA – Part II of a California Workers’ Compensation Institute (CWCI) research series on low-volume/high-cost drugs used to treat California injured workers identifies three Dermatological drugs, three Opioids, and three Antidepressants that represent a relatively small share of the prescriptions within their therapeutic drug group, but due to high average reimbursements, have become cost drivers, consuming a disproportionate share of the payments.

The new report is the second of a three-part series that uses data from the Institute’s Prescription Drug Application to track changes in the distribution of California workers’ compensation prescriptions and pharmacy payments over the past decade, and to identify medications that have a disproportionately large impact on the total amount paid for drugs within their group.  The report notes changes in the average payment per prescription for the highlighted drugs over the 10-year study period (2012 through 2021), changes in the percent of the prescriptions dispensed as a brand rather than a generic drug, and factors that contribute to the high cost of the medications.    

The report reveals that Dermatologicals were the fourth most prevalent drug category in 2021, with 9.3% of the workers’ comp prescriptions, but ranked second (behind Anti-Inflammatories) in total drug spend, consuming 17.3% of all prescription drug payments.  That was up from 12.8% in 2012, which the study ascribes to increased utilization and the emergence of high-priced topical analgesics.  Diclofenac sodium topicals jumped from 0.5% of all workers’ comp prescriptions in 2012 to 5.4% in 2021 – fourth among all drugs dispensed that year, and they represented 58.1% of the 2021 Dermatological prescriptions, but with inexpensive generics widely available, their average reimbursement was a relatively low $65, so they consumed only 23.5% of the Dermatological dollars.  In contrast, the study notes three other low-volume/high-priced drugs that have become Dermatological cost drivers:   

  • Diclofenac sodium and adhesive sheets (dispensed as Xrylix kits, in 2021 these kits accounted for just 0.3% of the Dermatological prescriptions, but with an average payment of $4,126, they consumed 7.2% of the dermatological drug spend).
  • Lidocaine/menthol (this drug was dispensed in various forms, but NuLido gel and Terocin patches were key cost drivers. Lidocaine/menthol represented only 1% of the Dermatologicals dispensed in 2021, but at an average of $1,050 per prescription, it accounted for 6.2% of the Dermatological payments. 
  • Diclofenac epolamine (dispensed as Flector patches at an average of $570 per prescription, or as generic equivalents at an average of $577, diclofenac epolamine comprised just 1.7% of the 2021 Dermatological prescriptions, but 5.9% of the payments within the group).

Opioid use in workers’ comp has been falling for more than a decade and with the adoption of Opioid and Pain Management Treatment Guidelines in late 2017 and a Formulary in 2018, Opioids’ share of the prescriptions continued to drop, falling to 9.4% in 2021 (down from 29.4% in 2012), while their share of the total drug spend fell to 5.8% (down from 26.7% a decade earlier).  At the same time, the mix of Opioids used to treat injured workers shifted.  The study noted three low-volume/high-priced Opioids that have become cost drivers within their group: 

  • Buprenorphine, typically used to treat Opioid Use Disorder for patients in Medication-Assisted Treatment plans, in 2021, it accounted for 5.2% of the workers’ comp Opioids, and with an average payment of $363, it consumed 35.4% of the total Opioid reimbursements – more than any other Opioid.
  • Tapentadol HCl, used when other pain medications do not work well or cannot be tolerated, but only available as a brand drug (Nucynta or Nucynta Extended Release) it represented just 0.6% of the Opioid prescriptions, but at $590 per prescription, it accounted for 6.4% of the total Opioid drug spend.  
  • Oxycodone, prescribed for moderate to severe pain, is available in a variety of generic and brand formulations, including extended-release and abuse-deterrent varieties. In 2021, 5.9% of Opioid prescriptions were for oxycodone, and at $145 per prescription, it consumed 16.0% of all Opioid payments.

The top four Antidepressants dispensed to injured workers in 2021 represented nearly 2/3 of the Antidepressants used, but all four were relatively low-cost drugs, so they accounted for only 42.5% of the payments in this drug group.  In contrast, the study identified three low-volume/high-priced drugs that consumed a disproportionate share of the Antidepressant drug spend:    

  • Vortioxetine HBr, used to treat Major Depressive Disorder, remains under patent and is only available as brand-name Trintellex. Available in 5, 10, and 20 mg tablets, this drug carries a black box warning noting an increased risk of suicidal thoughts and behaviors.  In 2021, only 1.0% of the Antidepressant prescriptions in California workers’ compensation were for Vortioxetine HBr, but with an average reimbursement of $476, this drug comprised 12.4% of all Antidepressant payments.   
  • Desvenlafaxine, an extended-release tablet that comes in various strengths, is used to treat major depression.  It is available as a brand drug (Khedezla, Pristiq), with average payments as high as $642 per prescription, but since the introduction of generic versions in 2017, brand versions have declined to 14 to 15% of the prescriptions.  Payments for generic desvenlafaxine averaged $58 to $66 from 2019 to 2021, which helped drive down the average reimbursement for this drug.  In 2021, desvenlafaxine represented 1.0% of workers’ comp Antidepressants, but the average payment was still $131, so it accounted for 3.5% of the Antidepressant payments.
  • Bupropion HCl is used to treat depression, anxiety, and other mood disorders, and to aid smoking cessation. Available as a brand drug (Wellbutrin, including an extended-release version that tends to be very expensive), or in generic versions, which accounted for 98% of the Bupropion HCl dispensed to injured workers in 2021. Unlike generics, where the average payment declined from $121 in 2012 to $25 in 2021, over that same decade average reimbursements for brand versions of bupropion HCl increased nearly 10-fold from $267 to $2,614.  The dominance of generic buproprion HCl has helped contain the total payments for this drug, but the 2% of the prescriptions dispensed as high-cost brand drugs drove the average payment up to $77 in 2021 -- more than three times the $25 average paid for generics.  As a result, bupropion HCl, which accounted for 7.6% of the Antidepressant prescriptions in 2021, consumed 16.3% of the Antidepressant payments. 

CWCI has published more details and analyses on these drugs in a Spotlight Report, Cost-Driver Medications in the Top California Workers’ Comp Therapeutic Drug Groups: Part II, Dermatologicals, Opioids, and Antidepressants.  Institute members and subscribers can log on to and access the report under the Research tab, others can purchase a copy from the CWCI’s online store.  Part III of CWCI’s research on low-volume/high-cost medications will focus on medications found in the Musculoskeletal and Ulcer drug categories.