WASHINGTON — Anti-addiction activists are calling for the Food and Drug Administration’s top official to step down, saying the agency’s policies have contributed to a national epidemic of prescription painkiller abuse.

In a letter released today, more than a dozen groups ask the Obama administration’s top health official to replace FDA Commissioner Dr. Margaret Hamburg, who has led the agency since 2009. The FDA has been under fire from public health advocates, politicians and law enforcement officials since last October, when it approved a powerful new painkiller called Zohydro against the recommendation of its own medical advisers.

The new letter is the first formal call for new leadership at the FDA over the issue.

“We are especially frustrated by the FDA’s continued approval of new, dangerous, high-dose opioid analgesics that are fueling high rates of addiction and overdose deaths,” states the letter, which is addressed to Health and Human Services Secretary Sylvia Burwell, who oversees the FDA and other health agencies. The groups signing the letter include Physicians for Responsible Opioid Prescribing, a 900-member advocacy group that petitioned the FDA to drastically restrict opioid use. The FDA rejected that petition last year.

A spokeswoman for the Department of Health and Human Services said opioid abuse “is a serious issue and one that the secretary is focused on.”