FRANKFORT, Ky. — The Kentucky Senate will reject a proposed first-in-the-nation tax on prescription opioids, with the chamber’s top Republican leader saying the idea has too many legal problems for it to be in the foundation of a two-year state spending plan.

The state’s House of Representatives approved the 25-cent per dose tax earlier this month, saying it would bring in about $140 million over the next two years. Lawmakers planned to use that money, plus revenue from an accompanying 50-cent hike in the cigarette tax, to pay for public education among other state services.