More drug addicts are using crack cocaine, yet treatment services are still geared more to heroin dependency, experts warn.
Rocks of crack cost about £25 each
Social care charity Turning Point says treatment providers often lack both knowledge about crack and confidence in addressing crack users' needs.
The 2003/04 British Crime Survey found more people in England and Wales used crack than heroin.
Yet 12 times as many heroin users are in treatment, Turning Point says.
Made from "washing" cocaine together with baking soda
This forms lumps or "rocks" which are then smoked
Name comes from noise it makes when smoked
Can also be injected
Gives an extremely intense but short-lived high
Side-effects include paranoia and aggression
Habit can cost £500+ per week
The charity says it is concerned about a particularly chaotic group of people who use both crack and heroin heavily, who face severe health and social problems and are responsible for a disproportionate level of drug-related crime.
Turning Point chief executive Lord Victor Adebowale said: "Crack misuse is a steadily growing social problem.
"Without urgent action, we face an escalation of the crack problem and a continued growth in the number of crack users in future generations.
"It is transforming the UK drug markets and our response to tackling it needs to equally transform.
"The government has taken significant steps but it is not moving quickly enough and neither are treatment agencies."
Part of the problem is that there is no substitute drug for crack, unlike methadone for heroin users.
Another is access - as users try to come off the drug they want help around the clock, but services are often not open 24 hours a day, seven days a week.
Harm reduction services tend to be tailored towards opiate use and may not be appropriate for the needs of cocaine users.
For example, needle exchanges may not provide enough needles for crack users who inject more frequently than users of heroin.
It is not always obvious to users what services are available and some, such as black and ethnic minority users, often feel excluded from existing services as they are less likely to use heroin or inject.
What is being done?
The National Treatment Agency (NTA) recognises the need to develop more effective services for those who misuse stimulants, particularly crack and cocaine.
It has established a programme specifically to address this issue and says although there is no "magic bullet", crack misuse is treatable.
Many approaches already familiar to drug services in Britain work well but none are specific to the treatment of crack dependence, says the NTA.
A spokeswoman said: "The reality now is that most drug users use a number of drugs, typically heroin and crack.
"The NTA's view and focus of work is that treatment services should be focused on the client - not the substance itself. Therefore all the drugs and associated problems that a drug user has should be managed during their care.
"We are working with drug treatment services and drug action teams to reconfigure treatment to ensure that it does meet the changing needs of drug users. This has started to happen but more needs to be done."
She said the NTA was working to develop appropriate training packages and identify and disseminate best practice, as well as developing a more reliable system for assessing drug use and treatment needs in local areas.