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Drug funding agency Pharmac is funding ritalin again for some sufferers of attention-deficit hyperactivity disorder (ADHD) after an alternatively funded drug has caused serious side effects in patients.
Pharmac switched its funding from ritalin to rubifen another, cheaper, methylphenidate medicine earlier this year.
Medsafe interim manager Dr Stewart Jessamine said between February and September 21 this year there had been 88 reports of people suffering adverse reactions within a few hours to days after changing to rubifen.
Most people reported a loss of therapeutic effect, while many had symptoms of aggression.
Others reported unusual psychiatric effects, including mood disorders and irritability. One person reported having hallucinations and two suicidal thoughts.
Dr Jessamine said it was common for some patients to respond to a medicine change, despite the active ingredient in the medication remaining the same, however in this case the severity of the side effects was unusual.
"Due to the number and severity of the adverse reactions reported to rubifen SR, and the absence of any reports of a similar nature for ritalin SR, Medsafe's medicines adverse reactions committee has asked Pharmac to make ritalin available to those patients who experience serious side-effects," he said.
Medsafe was investigating the product, seeking further information from the manufacturer about its quality and safety, and was conducting its own testing to determine the underlying cause of the side effects, Dr Jessamine said. This would take several weeks to complete.
It had extensively reviewed the manufacturing process, formula and testing of rubifen to determine the quality of the drug before it came onto the market in New Zealand, he said.
"To date there is no evidence to suggest that these side effects are due to a manufacturing problem or an issue with rubifen SR delivering the wrong dose of methylphenidate or delivering it too quickly."
Anyone taking rubifen who developed behavioural, psychiatric or other serious side-effects should contact their GP to discuss the best ADHD treatment option for them, he said.
Pharmac medical director Dr Peter Moodie said the move to fund ritalin was an appropriate and prudent response after Medsafe advised of a safety issue .
"It is important to stress that the advice relates specifically to patients who have changed brand and experienced an adverse reaction.
"No safety issues have been raised in relation to people who have changed brands and are well managed on rubifen."
The refunding of ritalin was an interim measure while Medsafe investigated the drug, Dr Moodie said.
"We will await with interest the outcome of that process."
Pharmac was writing to all doctors who prescribe methylphenidate to inform them about the issue, he said.
- NZPA
