Ethosuximide (Zarontin) 250 mg capsules: Brand change

Brand change Active

Your brand of ethosuximide is changing from Zarontin to Ethosuximide Essential Generics.

What's happening?

The supplier of Zarontin branded capsules can no longer source the Zarontin brand of ethosuximide. From January 2024, they will be supplying Ethosuximide Essential Generics brand.

It’s important to keep taking ethosuximide
Suddenly stopping epilepsy medicines can cause an increase in seizures. Your doctor, nurse or pharmacist will talk with you and answer your questions about this temporary medicine change.

There is no supply issue affecting the oral liquid of Zarontin brand of ethosuximide

The new brand looks different but works the same way

The Ethosuximide Essential Generics packaging and capsules look different. Each capsule has the same amount of active ingredient as Zarontin. It works in the body in the same way. 

The Ethosuximide Essential Generics is made by the same manufacturer as Zarontin, but at a different site. While the active ingredients are the same, the capsules have extra preservatives compared to Zarontin.

You may have already used this brand. Ethosuximide Essential Generics was supplied in 2022 when there was a shortage of Zarontin. 

Key differences:

  • capsule colour
  • capsule shape
  • number of capsules in a pack
  • some extra preservative ingredients
Contains 2 pictures of capsules. Zarontin brand capsules are opaque red with P-D 237 printed on them. Essentials brand capsules are rounder and clear with no colour.
Capsules not shown to scale
Zarontin box has Zarontin in bold capital letters and the Clinect logo. The Essential Generics packaging has a thick dark pink line bisecting the label. The dose (250 mg) and brand name appear in the same pink. Information about non-active ingredients als.
Comparison of ethosuximide packaging

Reduced number of capsules in a packet

Ethosuximide Essential Generics comes in a 56-capsule packet. The previous Zarontin brand came in a 100-capsule packet. 

People will still get the same number of capsules with each dispensing.

Not currently Medsafe-approved

Ethosuximide Essential Generics is not yet Medsafe approved, which means it has to be prescribed and supplied in line with section 29 of the Medicines Act. While not approved in New Zealand, Ethosuximide Essential Generics is approved in the United Kingdom. 

Data sheet and Patient information leaflet for Ethosuximide Essential Generics – link)

The supplier is applying to Medsafe for approval. However, we have listed this as a section 29 medicine in the meantime to make sure people can continue to get the medicine they need.

Prescribing and supplying an unapproved medicine

Section 29 of the Medicines Act 1981 allows for medicines that are not Medsafe approved to be prescribed and supplied to people. The medicine must be prescribed by someone registered with the Medical Council of New Zealand – such as, a doctor. 

We apologise for any inconvenience this causes. 

Advice for prescribing under section 29 – BPAC website(external link) 

Prescriber and pharmacist requirements for section 29 medicines – Medsafe website (external link)

Medsafe’s section 29 Declaration / Notification Form [DOC](external link)

What patients need to know about unapproved medicines – Healthify website(external link)