Mr Ewing said that voluntary organisations are a prime target for the extra cash, which is intended to help those who need treatment to get it as quickly as possible.
The increase was made possible by a decision to reduce spending on national projects in order to maximise the amount of money available for frontline drug services.
Mr Ewing said: "We want recovery to be the aim of all drug treatment and rehab services, and we all want to see a wider range of services in place than there has been in the past."
He also announced that £938,000 has been earmarked for a new drug treatment and rehab facility in Aberdeen. This will bring together professionals to offer services and treatment that best match the needs of individuals.
"This is about more than a building, impressive as the plans are. It's about offering hope for troubled lives and directions towards a road to recovery," he said.