Pharmaceutical firms are making it hard for President Donald Trump to fulfill his promise to address runaway prescription drug prices. Three days into the new year, drugmakers have already increased the list prices on hundreds of medications, with experts predicting more hikes in the weeks to come.

So far in 2020, prices on 411 drugs have increased an average of 5%, according to GoodRx, which tracks the cost of more than 3,500 drugs. Of the drugs that have seen rising prices, 407 were brand-name products and four were generic.

The drug with the biggest cost increase so far this year: Neos Therapeutics' Cotempla XR, a stimulant used to treat ADHD and narcolepsy, whose list price is up more than 13%. Other commonly prescribed drugs that are getting pricier include Eliquis (up 6%), often prescribed to prevent blood clots, and Humira (7.4%), used to treat inflammation in patients with autoimmune disease.

Drug prices are much higher in the U.S. than in other wealthy countries, where governments typically negotiate with manufacturers to control costs.

The Trump Administration last month announced a proposal to import prescription drugs from Canada in an effort to lower costs for consumers. But political barriers could sideline the plan, including opposition from the Canadian government and drug companies.

Still, experts commended the policy's goal of reducing drug costs in the U.S., where 1 in 8 individuals can't afford the heart disease medication they need to stay alive.