Hundreds of people in Northern Ireland with multiple sclerosis could be left behind as new therapies emerge to treat the condition, the MS Society has said.
Northern Ireland has one of the highest rates of MS in the world. Four thousand people suffer from the condition.
Concerns surround delays in getting new drugs and access to services.
The society is launching its Treat Me Right campaign on Monday. It wants people with MS to discuss treatments with healthcare professionals.
It also wants those healthcare professionals to outline what they will do to help people make informed choices about treatments.
"People need to discuss their options carefully with a MS nurse or neurologist to ensure they're making the right decision for them, whatever that may be," the MS Society's Patricia Gordon said.
"These new medicines mark a potential revolution in MS treatment - giving people with MS a wider number of effective treatment options.
"However, as a result, people with MS face increasingly complex decisions about which treatment is best for them. Many patients are left frustrated as they wait many months for an appointment to review their treatment.
"Others may go years without any treatment at all, as their MS worsens, unaware there could be effective, new options out there for them.
"It is therefore essential that our health service is more responsive, enabling everyone with MS to have more regular reviews with neurologists to ensure they have timely access to the right treatment at the right time."