Eltroxin

The Ministry of Health's drug regulatory arm Medsafe and Government drug-funding agency PHARMAC are well advanced in their efforts to source an alternative brand to the funded thyroid medicine Eltroxin.

Medsafe Group Manager Dr Stewart Jessamine says on September 3, Medsafe received its first application to seek approval for another brand of levothyroxine and he has been assured that an application for a second alternative is due to be submitted in the next week.

PHARMAC Funding and Procurement Manager Steffan Crausaz says PHARMAC will be able to give an update on funding an alternative within the next two weeks.

Since May of this year, when the numbers of adverse reactions to Eltroxin began to significantly increase, Medsafe has been contacting manufacturers and distributors of medicines encouraging them to submit an application for alternative brands of levothyroxine. "While any new products will still need to meet the required standards of safety, quality and efficacy before they can be approved, Medsafe will fast track the assessment of any applications it receives for levothyroxine to allow an approved alternative to be made available as promptly as possible," Dr Jessamine said.

Steffan Crausaz says approval by Medsafe is only the first step in the process of making a funded alternative to Eltroxin available and PHARMAC expects to complete negotiations with at least one of the alternative medicine supply companies shortly.

PHARMAC has been holding discussions with suppliers in parallel with Medsafe's work, and once a medicine has Medsafe approval, PHARMAC is well placed to move quickly on funding, says Steffan Crausaz.

"We need to be assured that sufficient stock will be available, and to consult with suppliers and the public on the listing arrangements."

Dr Jessamine says in the meantime the advice received from specialist endocrinologists is that many of the adverse reactions are consistent with some patients absorbing lower amounts of levothyroxine from the new tablets. In their expert experience, blood tests to check the level of thyroid hormone stimulating hormone (TSH), and adjustment of the dose of Eltroxin, either to increase the dose (or in some cases to decrease it) will lead to resolution of the patients symptoms over a few weeks to months. Patients taking Eltroxin who are worried about the product, or who have already changed to other brands of unapproved levothyroxine, should contact either Healthline on 0800 611-116 or their doctor, as they may need ongoing thyroid blood monitoring and dose adjustment.
Dr Jessamine confirmed the results of independent testing of both the old and new formulation of Eltroxin by ESR indicate the new Eltroxin tablets are acceptably potent and do not contain unexpected or excessive impurity content, compared to the old formulation, and meet the requirements for dissolution (a marker for how quickly the products dissolve). The batches of products tested include samples obtained from a pharmacy and from Eltroxin manufacturer GlaxoSmithKline (GSK).

Dr Jessamine says some of the claims being circulated about the product are wrong, such as:

it is not manufactured in India
its manufacture does not involve any genetic engineering
it does not contain MSG or any products not found routinely in other medicines.

The active ingredient (levothyroxine) in the new formulation is made in Austria by the same company, using the same method at the same site as the old formulation, and the finished product is manufactured in Germany. The other ingredients of the new formulation are routinely found in a range of other medicines and are not associated with increased rates of adverse effects.

The new GSK formulation of Eltroxin is currently marketed in close to 30 countries around the world. Medsafe has sought information from several of these countries where they have comparable adverse reactions reporting systems to New Zealand and it is clear they are not receiving increased numbers of reports for the new formulation product.

Medsafe also asked each of the 83 countries who make up the World Health Organisation Adverse Reactions Reporting System for any information they had on increased rates of reporting to GSK Eltroxin, or to adverse reactions following switches to brands of levothyroxine. The only positive feedback received came from the United Kingdom and Australia, countries where the GSK brand of Eltroxin is not available, who reported that they have small numbers of reports of adverse reactions that are similar in nature to those received in New Zealand but associated with patients shifting between different brands of levothyroxine.

While most patients (approx 99%) continue to have no major problems with the GSK Eltroxin, many of the side effects reported by the 800 individuals who have submitted reports to the New Zealand Pharmacovigilance Centre would be explained by changes in how these individuals absorb, metabolise or excrete the new formulation of Eltroxin compared to the old product.

Dr Jessamine says that while changing to a new levothyroxine product may resolve some of the problems where the person is allergic to, or intolerant of, the new formula of Eltroxin, patients will still need to have their blood tests monitored and it is quite likely that they will need to have the dose of any new brand of product adjusted to suit their individual metabolism. If patients wish to avoid adverse effects associated with increased or decreased thyroid activity that can occur following a switch in brands, so careful monitoring and dosage is essential.