The Pharmac spokeswoman said 4000 patients had been shifted onto an alternative drug, Concerta, since September.
They were now being encouraged to move back to Teva when stock became available.
While stocks were being replenished, many pharmacies were still unable to offer the medication. Patients told the Herald that they were still being prescribed Concerta last week.
A West Auckland parent told the Herald she was shocked when her pharmacist told her it was not possible to renew her 10-year-old son’s repeat prescription earlier this month.
“He said stocks had run out and there was a shortage of that particular medication nationwide and they were replacing it with Concerta.”
The mother said she felt “pretty alarmed” at being forced to change her son’s medication without the change being signed off by a psychiatrist, which had been required in the past.
She said it had taken a long time to settle on the right medication for her son. They had earlier tried Concerta, which had not suited him well.
However, the pharmacist insisted that they could switch to the new drug safely.
She was relieved to hear new stocks of the drug would soon be available.
ADHD New Zealand chief executive Suzanne Cookson said the shortage was “unfortunate”.
“People will spend months getting to the correct dosage or the correct kind of medication because there’s a range of options. So any change to that obviously does have an impact.”
Cookson said Pharmac had kept patients, pharmacists and doctors and other groups well-informed about the changes, which had helped ease the stress of the shortage.
She said some patients relied on the medication for study or to function properly at work.
“I’m not saying for a minute that everyone who has ADHD needs to be taking medication, but for those who have worked through the process and got the dosage and got the medication they need, it’s just so fundamental to their day-to-day life that it’s very difficult when that’s changed.”
Pharmac said it would keep updating patients on the supply issues on its website.
The shortage comes amid heightened attention about barriers and access to ADHD treatment and medication in New Zealand.
Pharmac said in September it would review the strict criteria for prescribing ADHD medicines.
At present, patients must be assessed every two years if they want to stay on the medication. This hurdle was designed to prevent misuse of the drugs.
However, workforce shortages mean this process can be slow and costly, and patients outside urban areas report waiting six or nine months for a psychiatrist appointment.
The issue was highlighted in a disciplinary hearing against an Auckland GP, Dr Tony Hanne, who was sanctioned this week for prescribing ADHD medicine without approval.
Hanne had argued that if he did not prescribe the medication, hundreds of patients would have missed out on potentially life-changing help in an under-pressure health system.
Pharmac is separately considering an application for a stimulant called lisdexamfetamine, which is less prone to abuse because it is a slow-release medication.
It is available in New Zealand, but without a subsidy, it costs around $100 a month.
These issues and other potential changes to diagnosis and treatment were discussed at a Parliamentary hui on ADHD last year, which was considered a milestone event by many in the health and disability sector.
Another proposal to emerge from that hui was whether GPs and nursing practitioners could play a greater role in diagnosis of ADHD and prescribing medicine.
An estimated one in 20 people in New Zealand have ADHD. A New Zealand Health survey shows that parents of two to 14 year-olds who report their child has been diagnosed with ADHD fluctuates between 1.5 and 3 per cent - though the condition is believed to be under-diagnosed.
Teva shortage
27mg and 54mg doses are now available for pharmacies to order in New Zealand;
18mg are available for pharmacies to order from today;
Shipment of 36mg doses has been delayed; Teva is waiting on confirmation of when stock will arrive in NZ.
Isaac Davison is an Auckland-based reporter who covers health issues. He joined the Herald in 2008 and has previously covered the environment, politics, and social issues.