The 3½-year-old was diagnosed with juvenile arthritis 12 months ago and his parents credit the wonder drug Naprosyn with treating the crippling illness and improving his quality of life.

But the drug company which imports the anti-inflammatory pain killer withdrew the oral suspension form of the drug from the Pharmaceutical Benefits Scheme and only about 80 bottles are left in the country. Hundreds of children including more than 35 in Canberra will be affected.

Belinda and Scott Milne said they face the prospect of their son's condition deteriorating.

''The supply of Naprosyn is being stopped despite it being a key medication to reduce severe pain, prevent crippling disability and blindness in young children,'' Mr Milne said.

The couple say the drug was withdrawn without notice and alternative medications are not as effective.

Mrs Milne said a bottle of the medication usually cost the family $5. This week the price rose to $88.

A spokesman for the Department of Health and Ageing said the government was ''powerless''.

''The Australian government cannot compel a manufacturer to continue to list a product on the PBS if the company does not wish to do so,'' the spokesman said.

And a spokeswoman from Roche, the pharmaceutical company which produced the liquid form of the medication and imported it, denied it was a financial decision.

''Roche discontinued global production and supply of Naprosyn oral suspension due to low volume and the availability of other alternative medicines,'' the spokeswoman said.

''Roche is aware of a number of overseas manufacturers of Naprosyn oral suspensions. Healthcare professionals and their patients should discuss whether personal importation of medicines from overseas is an appropriate option,'' she said.

Victoria Evans said the government had a duty to ensure that medications were available even after the copyright expired and it becomes less profitable for pharmaceutical companies to sell. Her daughter, Evie Buttsworth, has juvenile idiopathic arthritis and turns three next week.

''We first realised there was a problem two weeks after her first birthday … she was failing to thrive … it took us seven months to get a diagnosis,'' Ms Evans said.

There are five types of juvenile idiopathic arthritis and Evie's disease responds well to Naprosyn.

''Evie's relatively lucky she only has three joints affected and Naprosyn has controlled two out of the three joints,'' Ms Evans said.

The 40-year-old said her daughter was now a happy, cheeky girl who was able to run.

''Before she couldn't sleep, she couldn't eat. She cried a lot; she looked really exhausted … people said she looked haggard. A one-year-old that looked haggard.''

The tablet forms of Naprosyn are still available on the PBS but Ms Evans said that Evie cannot swallow pills.

The chief executive officer of the Arthritis foundation of the ACT, Helen Crig, said four out of every 1000 children have juvenile idiopathic arthritis with more than 35 children in the ACT being treated by rheumatologists.

She said the foundation was trying to work with government and the pharmaceutical company to restore the supply.