rans (buprenorphine) Transdermal System is “a partial opioid agonist product indicated for the management of moderate to severe chronic pain in patients requiring a continuous, around-the-clock opioid analgesic for an extended period of time.” According to the Full Prescribing Information
, initial Butrans dosing should be based on the individual patient’s prior analgesic treatment experience, and should be titrated as needed “to provide adequate analgesia and minimize adverse reactions.”
In a poster titled “Dosing of Patients Newly Treated with Butrans (Buprenorphine Transdermal System),” presented at the American Pain Society’s 32nd Annual Scientific Meeting, held May 8-13, 2013, in New Orleans, LA, Pergolizzi, Ben-Joseph, Chang, and Pierz noted that “limited information is available regarding whether patients actually are prescribed the initial Butrans dose consistent with the recommended dosing schedule” in the product’s Full Prescribing Information. To assess whether patients are receiving the recommended initial dose of Butrans therapy, the authors evaluated pharmacy claims data from 10,457 patients who made a first Butrans pharmacy claim between January 1 and November 30, 2011 (defined in the study as the “index date”).
They then identified a hierarchical Butrans index treatment regimen based on concurrent use of other medications (a claim for which had to have been filed within 30 days of the index date). They reported 2,279 patients were on Butrans monotherapy, 6,712 patients received a prescription for another opioid medication, 483 patients were prescribed an NSAID, and 983 patients were prescribed an adjuvant medication (including TCAs, anticonvulsants, muscle relaxants, and local anesthetics.
The authors compared initial dosing based index Butrans regimen and also based on the patient’s prior experience with opioids. Patients were classified as “opioid-experienced” if they had any pharmacy claim in the six months prior to initiating Butrans therapy, and “opioid-naïve” if they had no opioid pharmacy claim in the six months prior to the index date.
The mean age of study participants was 54 years, with three-quarters of patients between the ages of 18 and 64 (70% female, 30% male). The majority of patients (91.7%) were opioid-experienced. The breakdown of initial Butrans dosing was: 5 mcg/hr (52.3%), 10 mcg/hr (40.0%), and 20 mcg/hr (7.7%).
Patients reported a high rate of comorbid conditions prior to index date, with back pain (68.8%), musculoskeletal pain (58.5%), and osteoarthritis (40.6%) the most common. Fibromyalgia (19.8%), neuropathic pain (16.7%), and chronic pain (16.6%) were also frequently reported. Patients who had previously used opioid medications reported higher rates in nearly all pain conditions compared to opioid-naïve patients.
Analysis of the data showed 73.5% of opioid-naïve patients received the recommended initial dose of 5mcg/hr, 22.5% received a dose of 10 mcg/hr, and 4.0% received 20 mcg/hr.
Overall, 50.3% of opioid-experienced patients received the recommended starting dose. Sixty-five percent of patients whose prior morphine-equivalent daily dose (MED) was < 30 mg (n=1,390) received the recommended starting dose of 5 mcg/hr, 30.6% received a dose of 10 mcg/hr, and 4.0% received 20 mcg/hr.
The numbers were poorer for patients whose prior MED was 30-80 mg (n=5,583); only 41.1% received the recommended starting dose of 10 mcg/hr. More than half (52.3%) received 5 mcg/hr and 6.6% received 20 mcg/hr.
Of the 2,617 patients whose prior MED was > 80 mg, 38.3% received a starting dose of 5 mcg/hr, 48.5% received a dose of dose of 10 mcg/hr, and 13.2% received 20 mcg/hr, despite that fact that Butrans is not recommended for patients with this level of prior opioid exposure.
More than half of patients who were taking another medication in addition to Butrans received starting doses of 10 mcg/hr (42.6%) or 20 mcg/hr (8.1%).
Based on their analysis of these data, the authors concluded that “only about one-half of the patients received an initial Butrans prescription consistent with the dose initiation paradigm” described in the product’s Full Prescribing Information. In fact, 37.2% of patients in the study “were initiated on Butrans therapy at a dose that appears to be lower than recommended.” This could be due to a conservative opioid dosing approach or lack of provider knowledge/awareness of the dosing recommendations for this drug. Because of this, the authors argued that “it is important to monitor these patients for both tolerance and analgesic response to avoid inadequate treatment of their pain.”
The current study had several limitations identified by the authors, including the lack of information in claims data about the rationale for initial dose selection, and lack of information as to whether patients took their medications as prescribed.
The authors advised that based on their results, clinicians should consider the patient’s prior use of opioids and concomitant use of other medications when initiating Butrans therapy.