Heroin-related admissions at one of Sydney's largest rehabilitation clinics have trebled over the past 12 months, while ice continues to make an impact.

A third of admissions to one of Sydney's largest rehabilitation clinics are for ice addiction.

But Sydney's Odyssey House has warned authorities not to let the "ice epidemic" distract from the fight against alcohol and other prohibited drugs.

The centre treated 625 patients during the 2014-15 financial year, with amphetamines like ice and speed dominating admissions.

However, heroin-addicted patients almost tripled in the same period, accounting for 29 per cent of admissions.

Alcoholism was the main drug of concern for more than 20 per cent of admissions, while seven in 10 patients listed drinking as a major personal problem.

Odyssey House CEO James Pitts said the government's strong response to the National Ice Taskforce report was encouraging, but should not distract from the problems associated with other drugs.

He said it was common for people to switch drugs based on price and availability.

"Ice is a significant health problem, so more funding will help us deal with the high demand and address the treatment challenges," Mr Pitts said.

"However, the huge increase in people seeking our help for dependence on opioids like heroin is a very worrying trend.

"When Odyssey House admissions for amphetamine use go down, heroin admissions go up and vice versa.

"Peoples' life problems stay the same, it's just the drugs they use that change."

DEPENDENCY: ODYSSEY HOUSE ADMISSIONS 2014/15:
* 32 per cent for amphetamine addiction
* 29 per cent for heroin dependence, an increase of 164 per cent on the previous year
* 22 per cent for alcoholism
* 14 per cent for cannabis addiction
* 46 per cent of clients have at least one mental illness, such as depression.