Phenobarbitone (15 mg and 30 mg tablets): Brand change

What's changing

API, the supplier of the ‘PSM’ brand of phenobarbitone tablets (15 mg & 30 mg), closed its New Zealand manufacturing plant and is no longer supplying product in New Zealand. 

Medsafe has approved the Noumed 15 mg tablet for people to change to. It was listed in the Pharmaceutical Schedule from 1 March 2024. There was enough stock of the previous brand (PSM) to last until May 2024. 

Phenobarbitone tablet Medsafe Datasheet [PDF](external link)

People taking the 15 mg 'PSM' brand of phenobarbitone will need to start the process to change brand to the Noumed brand.

People taking the 30 mg phenobarbitone tablets changed brand to Noumed by December 2023.

Unaffected products

This brand change only applies to the 15 mg and 30 mg tablets. It does not affect parenteral phenobarbitone, phenobarbitone powder or injections. 

About phenobarbitone

Phenobarbitone is mostly used to treat epilepsy. About 400 people in Aotearoa New Zealand take it.

It is a category 1 antiepileptic agent according to the UK's Medicines and Healthcare products Regulatory Agency (MHRA).

MHRA's advice on antiepilepsy agents(external link)

People who take phenobarbitone tablets

We know that changing brands of phenobarbitone is not ideal. Unfortunately, with the closure of the manufacturing plant for PSM phenobarbitone tablets, there is no choice but to change brand.

We are working to support healthcare professionals and you as best we can, while ensuring New Zealanders can continue to receive funded access to phenobarbitone tablets.

Two visits to your GP needed 

If you take 15 mg phenobarbitone tablets for epilepsy, you needed to visit your GP twice to discuss changing brands:

• About 1 month before you start taking the new brand of phenobarbitone
• About 1 month after you start taking the new brand of phenobarbitone.

You didn't need to pay for these appointments. Pharmac covered GP visit payments. Funding was available until 31 July 2024.

Four blood tests needed

The experts on our Neurological Advisory Committee recommended a monitoring programme to help you through the change. You needed to get 4 blood tests so your GP can monitor your progress.

You'll need blood tests:

• 3 weeks before you start taking the new brand of phenobarbitone tablets 
• the same week you start taking the new brand (but before you start taking it)
• 4-10 days after you start taking the new brand
• 1 month after the brand change.

These tests will check the concentration of phenobarbital in your body. You will not need to pay for these tests. If you can't get to a collection site where these tests are funded, Pharmac will cover the cost. 

Get Noumed brand after your first blood test

If you’ve had first of these serum tests, please collect Noumed Phenobarbitone 15 mg tablets from your pharmacy. 

Brand change flyer [PDF] - Healthify(external link)

About phenobarbitone - Healthify(external link)

People who prescribe phenobarbitone tablets

We asked that you alert anyone taking 15 mg phenobarbitone tablets for epilepsy to the brand change and book them in to see you. They needed to visit you twice – once before and once after the brand change.

Once you organised the first of the serum tests, you needed to note on the prescription that Noumed Phenobarbitone 15 mg tablets needs to be dispensed from the pharmacy. 

If someone who is taking phenobarbitone is pregnant (or could get pregnant), get timely neurologist advice to inform a management approach and refer to advice in HealthPathways. 

Pharmac funding the co-payment

Pharmac funded the patient co-payment for these appointments. The reimbursement of waived patient co-payment and laboratory fees was available until 31 July 2024.

Clinical advice about the brand change

Pharmac’s Neurological Advisory Committee advised that you needed to carefully monitor people taking phenobarbitone tablets when they change brands. 

This includes organising serum testing for your patients. If your patients can't get to a collection site where this test is funded, Pharmac covered the costs for the serum testing.

Record from the Advisory Committee's discussion of the phenobarbitone brand change [PDF, 270 KB]

He Ako Hiringa developed resources to support you as your patients make this transition. It includes more information about phenobarbital serum testing.

Pharmacists who dispense phenobarbitone tablets

Noumed Phenobarbitone 15 mg tablets were listed from 1 March 2024. If you are aware of someone taking phenobarbitone 15 mg tablets, please:

• Alert them to the upcoming brand change
• Make sure they have see their doctor about the brand change
• Dispense Noumed Phenobarbitone 15 mg tablets if they’ve had their first serum test.

Monthly dispensing from 1 February

From 1 February 2024, all-at-once (‘stat’) dispensing was removed from phenobarbitone tablets. The dispensing frequency changed to monthly dispensing. This brings the Schedule listing for phenobarbitone tablets in line with the legislation. 

Phenobarbitone is a Class C5 controlled drug under the Misuse of Drugs Act 1975. Under Regulation 31(1)(d)(external link) of the Misuse of Drugs Regulations 1977, the legal maximum amount that can be dispensed at one time is one month. A total of three months can still be prescribed.

Ministry of Health (Manatū Hauora) made the change to Regulations after consulting with the sector about the prescribing and dispensing of controlled drugs.

Controlled drugs - Ministry of Health(external link)

Who to contact

If you take phenobarbitone, please talk to your GP or pharmacist. Pharmac cannot comment on anyone's individual clinical circumstances. Your GP or pharmacist know you best.

If you have other questions about this brand change, email enquiry@pharmac.govt.nz