Hysteria about drugs policy is marring debate on controversial issues such as the use of heroin substitute methadone, according to the Scottish Liberal Democrat leader.

Health professionals should not be held back by ill-thought-out political ideology, Willie Rennie said before a Holyrood debate on the issue today.

"If we are to give drug users a real chance of survival, we should be arming health professionals with more tools, not stripping them away," he said.

"In recent months the consensus on the drugs dilemma has been marred by hysteria."

The Scottish Government, which will lead the debate in Holyrood, called on MSPs to recognise progress in delivering the national drug strategy, the Road to Recovery.