America's drug epidemic is the deadliest it has ever been, new federal data suggests.More than 100,000 people died of drug overdoses in the United States during the 12-month period ending April 2021, according to provisional data published Wednesday by the U.S. Centers for Disease Control and Prevention.That's a new record high, with overdose deaths jumping 28.5% from the same period a year earlier.Opioids continue to be the driving cause of drug overdose deaths. Synthetic opioids, primarily fentanyl, caused nearly two-thirds (64%) of all drug overdose deaths in the 12-month period ending April 2021, up 49% from the year before, the CDC's 's National Center for Health Statistics found.The COVID-19 pandemic and the rise in use of fentanyl have both been key contributors to the rising overdose death toll, experts say.The latest provisional data on drug overdose deaths captures those occurring in May 2020 through April 2021. COVID-19 killed about 509,000 people in that same timeframe, according to data from Johns Hopkins University."What we're seeing are the effects of these patterns of crisis and the appearance of more dangerous drugs at much lower prices," Dr. Nora Volkow, director of the National Institute on Drug Abuse, told CNN. "In a crisis of this magnitude, those already taking drugs may take higher amounts and those in recovery may relapse. It's a phenomenon we've seen and perhaps could have predicted."But the rise of fentanyl, a stronger and faster-acting drug than natural opiates, has made those effects even more deadly, she said.Increasing use of the synthetic drug caught the attention of experts before COVID-19 hit, but the pandemic may have exacerbated the problem.With international travel limited, synthetics that are easier to manufacture and more concentrated were likely more efficient to smuggle across borders, Volkow said.The new federal data shows that overdose deaths from methamphetamine and other psychostimulants also increased significantly, up 48% in the year ending April 2021 compared to the year before. They accounted for more than a quarter of all overdose deaths in the latest 12-month period.While fentanyl was once more popular on the East Coast and methamphetamine on the West Coast, Volkow says both have now proliferated nationwide.Deaths from cocaine and prescription pain medication also increased compared with a year earlier, but not as drastically.As the country reopens and society returns to some pre-pandemic normalcy, experts say people will continue to die from drug overdoses at very high rates if action isn't taken to significantly improve access to treatment."Even if COVID went away tomorrow, we'd still have a problem. What will have an impact is dramatic improvement to access to treatment," said Dr. Andrew Kolodny, medical director of opioid policy research at the Brandeis University Heller School for Social Policy and Management."These are deaths in people with a preventable, treatable condition. The United States continues to fail on both fronts, both on preventing opioid addiction and treating addiction," he said, emphasizing the need for President Joe Biden to deliver on his campaign promises to address the crisis.Last month, the U.S. Department of Health and Human Services released an overview of the Biden administration's plan to combat drug overdoses. It includes measures aimed at addressing opioid prescription practices and removing barriers to treatments, as well as recovery support and federal support for harm reduction strategies.On Wednesday, the White House Office of National Drug Control Policy released a model law, providing states with a template to pass their own legislation to improve access to naloxone, a drug that reverses opioid overdoses."If we really want to turn the corner, we have to get to a point where treatment for opioid addiction is easier to access than fentanyl, heroin or prescription opioids are," Kolodny said, referring to medications including buprenorphine."The evidence is really clear that using medications to treat opioid addiction disorders saves lives," said Beth Connolly, director of the Pew Charitable Trusts substance use prevention and treatment initiative. "As we see more and more evidence that (medication) does save lives, that will hopefully reduce stigmatizing and categorizing in favor of supporting individuals."Provisional overdose death data is updated monthly by the NCHS and is subject to change, as drug overdose deaths often require "lengthy investigation, including toxicology testing" to confirm cause of death.In 2019, heart disease was the leading cause of death in the U.S., according to data from the CDC, killing nearly 660,000 people. Cancer killed nearly 600,000 people in 2019, while accidents, chronic lower respiratory diseases, stroke and Alzheimer's disease also caused more than 100,000 deaths each. These figures reflect final, annual updates and are not directly comparable to provisional data.