Last month Arizona became the 15th state since 2016 to impose a statutory limit on the length of initial opioid prescriptions for acute pain. The rationale for such laws is that shorter prescriptions will mean fewer pills in circulation and less potential for abuse and diversion. But recent research suggests the opposite may be true, because patients tend to get refills when the initial prescription is too short.
According to guidelines published by the U.S. Centers for Disease Control and Prevention in March 2016, "three days or less will often be sufficient" when doctors prescribe opioids for acute pain, and "more than seven days will rarely be needed." State legislators seem to have taken that recommendation to heart. In 2016 and 2017, according to a tally by the National Conference of State Legislatures (NCSL), 14 states enacted limits on such prescriptions, ranging from three days (Kentucky) to two weeks (Nevada), with seven days the most common. Arizona picked five days.
One obvious problem with such arbitrary limits is that some patients recovering from surgery or injuries will need more than three, five, or seven days of pain medication. That is a problem for those patients, but it is also a problem for politicians trying to prevent nonmedical use. A study published last month by JAMA Surgery found that prescription lengths similar to those mandated by most of these state laws were associated with a higher likelihood of refills for some types of surgery. "While government restrictions often limit the dispensing of opioid prescriptions to 7 days or less," MedPage Today noted, this study suggests that "longer initial opioid prescription lengths following certain surgical procedures may, in fact, limit the need for refills and decrease total opioid use."
Harvard surgeon Rebecca Scully and her collaborators looked at prescription data for more than 200,000 patients who took pain medication after surgery, 19 percent of whom received at least one refill. The prescription length associated with the lowest probability of a refill was nine days for general surgery, 13 days for women's health procedures, and 15 days for musculoskeletal procedures. "In practice," Scully et al. conclude, "the optimal length of opioid prescriptions lies between the observed median prescription length and the early nadir," i.e., the point where a refill was least likely.
That rule of thumb would make the optimal prescription length four to nine days for general surgery procedures, four to 13 days for women's health procedures, and six to 15 days for musculoskeletal procedures. "Although 7 days appears to be more than adequate for many patients undergoing common general surgery and gynecologic procedures," Scully et al. write, "prescription lengths likely should be extended to 10 days, particularly after common neurosurgical and musculoskeletal procedures, recognizing that as many as 40% of patients may still require 1 refill at a 7-day limit."
Some states with prescription limits (including Arizona) make exceptions for postsurgical pain, but the NCSL summary indicates that most do not. A legal limit of seven or fewer days not only interferes with proper patient care; it may increase rather than reduce the number of pills ultimately dispensed.