The transition from the painkiller Oxycontin to a new formulation has led to some troubling trends in Ottawa, as police report a rash of pharmacy robberies and doctors say addicts are moving on to other narcotics.

The drug company Purdue Pharma stopped manufacturing Oxycontin in Canada in March, and replaced it with a new type of oxycodone called OxyNeo that is harder to abuse because it cannot be easily crushed or injected to get high.

Oxycontin can no longer be prescribed, but some pharmacies still have the drug in small quantities, making them a target for robberies, police say.

Royal Ottawa Hospital addictions expert Dr. Melanie Willows said Oxycontin addicts are taking less of the drug, but only a small number are seeking help to wean off the drug.

The majority, she said, are moving to other narcotics such as fentanyl and dilaudid.

"Probably quite a few number of them will turn to other opioids ... Fentanyl ... tomorrow it's something else," said Willows.

Recovering addict Tony Sabourin said the transition to the new drug has already claimed three people he knows who unsuccessfully tried to cook OxyNeo and inject it earlier this month.

"He had been struggling with oxy addiction for five years and he ended up trying to inject it and didn't make it," said Sabourin.

The problem has also added to a backlog for treatment at the Royal Ottawa as addicts battle withdrawal.

Pharmacy robberies are also up this calendar year, as so far in 2012, 38 drug stores have been robbed in Ottawa. That nearly matches the 40 drug store robberies in all of 2011.

Staff Sgt. Mike Haarbosch said the low supply of the drug and high demand is the likely reason for the spike in robberies.

"Demand for some of the drugs both to sustain a habit and alternatively for resale on the street to satisfy the need and habit," said Haarbosch.