The Centers for Disease Control and Prevention (CDC) issued new guidelines for doctors on prescribing opioids for pain, NBC News reports.

The new guidelines update and replace the CDC’s 2016 guidelines. Some experts said the previous guidelines, while reducing inappropriate and dangerous prescribing, were also seen as a barrier to care. Some pharmacists refused to fill opioid prescriptions as clinicians wrote them.

Under the new guidelines, the CDC no longer recommends trying to limit opioid treatment for acute pain to three days. The CDC dropped the recommendation that doctors avoid increasing dosage to a level equivalent to 90 milligrams of morphine daily. The new guidelines urge doctors not to suddenly stop treatment for patients receiving higher doses of opioids, unless there are indications of a life-threatening danger. The CDC offers suggestions on tapering patients off opioids.

“The science on pain care has advanced over the past six years,” Debbie Dowell, MD, MPH, chief clinical research officer for CDC’s Division of Overdose Prevention, said in a news release. “During this time, CDC has also learned more from people living with pain, their caregivers, and their clinicians. We’ve been able to improve and expand our recommendations by incorporating new data with a better understanding of people’s lived experiences and the challenges they face when managing pain and pain care.”