The ability to obtain advanced rheumatoid arthritis drugs on the NHS is still determined by where patients live, a study has suggested.
Anti-TNF drugs have been found to slow the progress of arthritis
The disparity exists despite National Institute for health and Clinical Excellence approval for anti-TNF drugs, the Rheumatology journal research said.
Such drugs help block the inflammation which causes pain to people with RA.
But local health groups said funding shortages meant limits on prescribing them had to be imposed.
The head of the body which represents primary care trust said the government had made balancing the books their main priority.
Anti-TNF (anti-tumour necrosis factor alpha) therapy drugs were approved by NICE for the treatment of RA, caused by inflammation of the lining of the joints, in November 2002.
Research has shown anti-TNF therapy helps those with RA as well as other forms of the condition, slowing the progress of disease and helping to reduce symptoms such as joint pain, swelling, mobility and fatigue.
Researchers from the British Society for Rheumatology Biologics Register, which monitors the use of the drugs, sent questionnaires to 509 consultant rheumatologists in the UK, and 252 responded.
The consultants revealed a wide disparity in the provision of anti-TNF therapy across the country.
Just under half said there was some limitation on their ability to prescribe anti-TNFs to people with RA.
A cap on funding or instructions to treat a fixed number of patients per month, or a ban on treating patients until the next financial year, were cited by 70% of those who said there were limits set by their primary care trust.
A fifth said insufficient staffing was a problem, while 9% said the issue was a lack of facilities.
Different PCTs also had different financial limits, while many also had waiting lists, some of which were up to two years.
The situation was found to be even worse for people being given anti-TNF drugs for other arthritic conditions such as psoriatic arthritis - where NICE approval has only just been given and ankylosing spondylitis - for which guidance is due to be published next year.
Only two-thirds of the consultants who responded said they had any access to the medications for these conditions.
Dr Lesley Kay, who led the research, said the government and PCTs had to end to the "patently unfair situation", which contravened government policy.
"The postcode lottery continues to operate, even though NICE aims to stop this happening.
"It's unfair on patients with these devastating, painful and unglamorous conditions to be forced to take a low priority and to be deprived of this very successful treatment."
A spokeswoman for the Arthritis Research Campaign said: "Once NICE has approved drugs for use, then patients who need them should be able to access them quickly, but we know there are substantial regional variations.
"It's deeply frustrating for patients and doctors when there is so much positive trial data - we know these drugs work."
But Dr Mike Dixon, chairman of the NHS Alliance which represents primary care trusts, said variations were likely to remain in access to drugs such as anti-TNFs.
"The health secretary has said the most important thing is that PCTs achieve financial balance, and that comes first - as do life-saving cancer drugs.
"Anything else, even though it might be useful and approved by NICE, is likely to find itself at the back of the queue."