Painkilling prescriptions up 20% in Wales in five years
The number of painkilling prescriptions being issued to patients in Wales has risen 20% in the past five years.
Experts say thousands of patients are receiving painkillers because specialist services to help them cope with chronic pain are underfunded.
Painkillers cost the Welsh NHS almost £50m last year.
In Wales, 30% of people are in pain and one in eight people suffer chronic non-malignant pain.
Baroness Finlay, professor of palliative care at Cardiff University School of Medicine, and consultant at Velindre Cancer Centre, said GPs were under pressure to prescribe painkillers because pain management services were not always available.
"I think if you look at the volume of prescriptions overall you have to question whether this is too high; you also have to question are they effective," she told BBC Wales' Week In Week Out programme.
"How do you say to someone who is sitting opposite you in pain 'No, I'm not going to prescribe for you'? They have to get the patients out through the door."
The British Medical Association accepts GPs are under pressure to prescribe painkillers because they are often short of time with patients.
It said there had been a 50% rise in the number of consultations in the last 15 years.
Five years ago every health board was given a set of directives by the Welsh government aimed at getting patients the most appropriate care at the right time.
It was meant to improve diagnosis and prevention of chronic pain at a primary level and increase access to specialised services in secondary care.
One of the authors of the directives, Dr Ann Taylor from Cardiff University, believes much more needs to be done for those in chronic pain in Wales.
She said: "You're twice as likely to die if you have chronic pain than for any other condition.
"But it doesn't have the resources and recognition that things like cardiac diseases, hyper-tension, respiratory and chronic respiratory conditions have.
"If you don't intervene early enough in the acute pain stages you're going to end up with complex chronic pain that you're not able to cure."
But not every health board has fully complied. Prof Finlay warned that pain management programmes needed to be a priority for the NHS in Wales.
She added: "You need to have somebody who is a champion. You need to have somebody who is going to provide the leadership and you need somebody who's going to say 'right, I'm going to fight this corner, and fight this cause and get this set up'.
Physiotherapy and counselling
"There has been a bit of a vocal voice in some trusts in Wales, and some areas have got pain management programmes but it's patchy and there really hasn't been at a national level leadership over chronic pain."
Wales has a number of pain management clinics, but according to the latest figures from the Welsh government 35% of patients treated in March had to wait longer than the six month target time for the appointment.
At Wales' only residential pain and fatigue management clinic at Bronllys Hospital near Brecon, patients are given a range of treatments including physiotherapy and counselling to help them live with pain.
Research carried out for the clinic showed that after five years a group of patients had reduced painkilling medication by 25%.
But when Week In Week Out filmed at the centre, there were empty beds as health boards struggle to find the£5,500 it costs per patient for a three-week stay at the clinic.
Mark Turtle, president of the Welsh Pain Society, who treats patients at Bronllys, said he was frustrated that health boards were not referring more patients there for treatment.
"Every person who comes in through the door, I know exactly what they want, but I can't supply it," he said.
"Not only am I impotent at supplying what they want but there's an added challenge here because here's a facility which I feel will benefit them and can't even offer them that."
Health Minister Mark Drakeford told the programme he supported the movement of treatment and care from acute care settings to community and primary care-based settings and recognised that some patients may require more specialist management through a multi-professional pain service.
He added that health boards had been encouraged to establish more robust community pain services linked with secondary care to support more effective pain management.